CN117940992A

CN117940992A - Sound system for enclosed space

Info

Publication number: CN117940992A
Application number: CN202180102120.0A
Authority: CN
Inventors: 藤原奖; 垂石圭悟; 相川真实
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2024-04-26
Also published as: WO2023042323A1; JPWO2023042323A1

Abstract

The sound system for an enclosed space comprises: a speaker system disposed in the closed space and mounted with a speaker unit; a storage unit that stores audio content; and a sound field control unit that irradiates a sound signal based on sound content to the enclosed space from the speaker system, the sound content including: a natural environmental sound representing environmental sounds generated in nature; and chord serial tones composed of combinations of chords including a chord and a non-chord.

Description

Sound system for enclosed space

Technical Field

The present invention relates to a sound system for an enclosed space for radiating sound into an enclosed space such as an elevator car.

Background

A car of a conventional elevator is provided with a speaker for guiding a voice of a user in the car. Further, an intercom for allowing a user to communicate with an external person in an emergency is provided in the car. These speakers and interphones are provided on, for example, a car operating panel.

In addition, in the conventional elevator, the following technology is proposed: not only voice guidance but also BGM (Background Music) is played in the car (for example, refer to patent document 1).

The elevator described in patent document 1 has 1 speaker provided in a car and configured to sound BGM (background music) together with a broadcast for guiding passengers. The elevator further includes a microphone provided in one of the car, outside the car, in the hoistway, and at the elevator landing. The microphone measures dark noise around the installation site, and the measurement result of the microphone is used for adjusting the broadcast volume. The dark noise is noise that is present in a certain place even when the main noise stops at that place. Further, the elevator described in patent document 1 includes a BGM sound volume automatic adjustment device that adjusts the volume of BGM that sounds from a speaker in a car. The BGM automatic volume adjustment device acquires information of an elevator and information of a setting building from an information center via an elevator control device or a communication control device. Then, the BGM sound volume automatic adjustment device obtains the corresponding BGM sound volume from the preset sound volume adjustment map based on the acquired elevator information and building information, and sets the sound volume of BGM sounded from the speaker in the car.

Generally, the interior space of the car of an elevator is required to ensure a certain degree of tightness and quietness. In addition, the same applies to the interior space of vehicles such as electric cars, buses, and taxis, and waiting spaces such as waiting rooms in hospitals and pharmacies. In such a special narrow enclosed space, which is different from a normal living space, a user does not talk with an unknown person. As a result, users often have "unpleasant feeling" and "unpleasant feeling", and stress is generated by them.

Accordingly, patent document 1 proposes the following technique: music is sounded as BGM (background music) from a car interior speaker. In patent document 1, the volume of BGM is adjusted based on elevator information (e.g., car capacity (number of persons)) and building information (e.g., use of a building) so as not to make an elevator user feel a sense of harshness.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2010-222127

Disclosure of Invention

Problems to be solved by the invention

In patent document 1, music is radiated from a speaker used in a broadcast for guiding passengers. Therefore, a speaker for providing music is an edge of a speaker for broadcasting. Therefore, for example, the speaker is disposed in the operation panel, and is required to be lightweight, thin, small, and mono-reproducing due to the influence of the installation environment in the operation panel. Therefore, the sound quality is very poor at the time of music reproduction, and is a sound radiation state that is significantly different from music reproduction or the like heard by audio equipment in the home.

In general, the number of elevators for reproducing music is very small, and in most cases, only 1 speaker is mounted as the minimum number. There are few examples of elevators that provide music to the elevator user for positive, stable or certain purposes.

In patent document 1, a technique of ringing music as BGM is proposed, but the category of music is not particularly mentioned.

The selection of music to be actually performed is determined by a building owner, a person in charge of an elevator maintenance company, or the like, and is therefore basically selected according to interests of the building owner, the person in charge, or the like. In addition, there is no sound content generated for the elevator, and existing sound content is generally used. Further, the action of generating a dedicated sound content in consideration of the pleasure and pressure reduction of the elevator user is not very visible at present. As a result, even if music is played in the car of the elevator, the elevator user may feel unpleasant to BGM. Further, since the same BGM is always used or BGM is selected on the system side irrespective of the likes and dislikes of the user, there arises a problem that the elevator user is not interested in the music type or the like. In this case, a case where the reproduction of BGM is understood as noise by the user is also considered. In this way, in the reproduction of BGM in patent document 1, the pressure caused by "uncomfortable feeling" and "unpleasant feeling" of the user may not be reduced, and depending on the circumstances, the pressure of the elevator user may also increase.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sound system for a closed space as follows: the sound content obtained by combining the natural environment sound generated in the natural world and the chord serial sound composed of the harmony and the non-harmony sound is reproduced, whereby the pressure of the user in the closed space can be reduced.

Means for solving the problems

The sound system for a closed space of the present invention comprises: a speaker system disposed in the closed space and mounted with a speaker unit; a storage unit that stores audio content; and a sound field control section that radiates, from the speaker system to the enclosed space, a sound signal based on the sound content including: a natural environmental sound representing environmental sounds generated in nature; and chord serial tones composed of combinations of chords including a chord and a non-chord.

Effects of the invention

According to the sound system for a closed space of the present invention, the pressure of the user in the closed space can be reduced by reproducing the sound content in which the natural environment sound generated in the natural world and the chord serial sound composed of the chord and the harmony sound are combined.

Drawings

Fig. 1 is a perspective view showing the structure of an elevator 1 according to embodiment 1.

Fig. 2 is a diagram showing a state of an inner space of the car 5 of the elevator 1 according to embodiment 1.

Fig. 3 is a block diagram showing the configuration of an audio content generating apparatus 40 that generates audio content 30 used in the audio system 13 according to embodiment 1.

Fig. 4 is an explanatory diagram illustrating the structure of audio content 30 used in audio system 13 according to embodiment 1.

Fig. 5 is an explanatory diagram illustrating the structure of the chord serial 30B included in the sound content 30 used in the sound system 13 of embodiment 1.

Fig. 6 is a front view showing the structure of the sound system 13 of embodiment 1.

Fig. 7 is a plan view showing the arrangement of the speaker box 20 of the sound system 13 of embodiment 1.

Fig. 8 is a side view showing an example of the structure of the speaker box 20 according to embodiment 1.

Fig. 9 is a front view showing the structure of the speaker box 20 of fig. 8.

Fig. 10 is a side view showing a structure of a modification of the speaker box 20 of embodiment 1.

Fig. 11 is a front view showing the structure of the speaker box 20 of fig. 10.

Fig. 12 is a front view schematically showing a configuration of a modification of the audio system 13 of embodiment 1.

Fig. 13 is a plan view schematically showing a configuration of another modification of the sound system 13 of embodiment 1.

Fig. 14 is an explanatory diagram schematically showing a time variation of the sound pressure level of the sound content 30 used in the sound system 13 of embodiment 1.

Fig. 15 is a basic explanatory diagram of the harmony sound 33 and the harmony sound 34 used in the sound system 13 of embodiment 1.

Fig. 16 is an explanatory diagram showing the relationship between "down" and "up" constituting the chord used in the sound system 13 of embodiment 1, using a list of "degrees".

Fig. 17 is a diagram showing an example of the definition of the harmony sound 33 and the harmony sound 34 used in the sound system 13 of embodiment 1.

Fig. 18 is a diagram showing an example of the harmony sound 33 used in the sound system 13 of embodiment 1.

Fig. 19 is a diagram showing an example of the harmony sound 33 used in the sound system 13 of embodiment 1.

Fig. 20 is a diagram showing an example of the mismatch 34 used in the audio system 13 according to embodiment 1.

Fig. 21 is an explanatory diagram showing an example of the characteristics of the frequency band used as the chord serial tone 30B used in the sound system 13 of embodiment 1.

Fig. 22 is a diagram showing instantaneous frequency characteristics when FFT processing is performed on the time waveform at the point (B) in fig. 4.

Fig. 23 is a diagram showing instantaneous frequency characteristics when FFT processing is performed on the time waveform at the point (a) in fig. 4.

Fig. 24 is an explanatory diagram illustrating an example of signal processing performed on the audio content 30 according to embodiment 1.

Fig. 25 is an explanatory diagram illustrating an example of signal processing performed on the audio content 30 according to embodiment 1.

Fig. 26 is an explanatory diagram illustrating an example of signal processing performed on the audio content 30 according to embodiment 1.

Fig. 27 is an explanatory diagram illustrating an example of signal processing performed on the audio content 30 according to embodiment 1.

Fig. 28 is a schematic diagram showing subjective evaluation results and physiological evaluation results of a person based on the SD method.

Fig. 29 is a diagram showing an example of the additional sound 32 inserted into the natural environment sound 30A of the sound content 30 every season and every living period.

Detailed Description

Next, an embodiment of the sound system for a closed space according to the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. The present invention includes all combinations of combinable structures among the structures shown in the following embodiments and modifications thereof. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and are common throughout the specification. In the drawings, the relative dimensional relationship, shape, and the like of the respective structural members may be different from the actual ones.

Embodiment 1

The sound system for an enclosed space according to embodiment 1 is applied to an enclosed space in which a certain degree of tightness and quietness are required to be ensured. Examples of the closed space include an interior space of an elevator car, an interior space of a vehicle such as a train, a bus, or a taxi, and a waiting space such as a waiting room of a hospital or a pharmacy. That is, the enclosed space to which the enclosed space sound system of embodiment 1 is applied is a special narrow enclosed space different from a normal living space. More specifically, the closed space according to embodiment 1 is a space in which 2 or more persons can be present, and has a structure in which the entrance is closed, and is a space in which a person who is present inside cannot go outside in principle for a certain period of time. Next, as the closed space, a space in a car of an elevator is exemplified.

Fig. 1 is a perspective view showing the structure of an elevator 1 according to embodiment 1. As shown in fig. 1, an elevator 1 is installed in a building and moves up and down in a hoistway 2. A hoisting machine 3 is provided at an upper portion of the hoistway 2. A main rope 4 is suspended on a sheave 3a provided in the hoisting machine 3. A car 5 and a counterweight 6 are connected to both ends of the main rope 4. The car 5 and the counterweight 6 are suspended in a bucket form from the sheave 3a by the main ropes 4. An elevator control panel 7 is provided at an upper portion of the hoistway 2. The elevator control panel 7 is connected to the hoisting machine 3 via a communication line and to the car 5 via a control cable 8. The control cable 8 transmits electric power and control signals to the car 5. The control cable 8 is also called a tail cable.

The car 5 is composed of 4 side plates 5a, a floor 5b, and a ceiling plate 5 c. The 4 side plates 5a are disposed on the right, left, front and rear sides of the car 5, respectively. Further, a car door 5d is provided to the front side plate 5a of the 4 side plates 5 a. When the car 5 stops at a landing on each floor, the car door 5d engages with a landing door (not shown) provided at the landing, and performs an opening and closing operation.

As shown in fig. 1, a car control device 9 and an acoustic field control device 21 are provided on the upper surface of a ceiling plate 5c of the car 5. The car control device 9 controls the operation of each device provided in the car 5. Examples of the devices provided in the car 5 include a car door 5d, a lighting device 5e (see fig. 2), and a car operating panel 5f (see fig. 2). The sound field control device 21 performs overall control of the operation of the closed space sound system 13 (see fig. 6), which will be described later, so as to form a three-dimensional sound field 27 (see fig. 6) in the entire inner space of the car 5. Hereinafter, the sound system 13 for the closed space will be simply referred to as a sound system 13.

As shown in fig. 1, a suspended ceiling 10 is fixed to the lower surface of a ceiling plate 5c of the car 5. The suspended ceiling 10 is located in the inner space of the car 5. The suspended ceiling 10 has a rectangular parallelepiped shape. The suspended ceiling 10 has 4 side surfaces 10a and a lower surface 10b (see fig. 2). The suspended ceiling 10 may further have an upper surface disposed to face the lower surface 10 b. Or the suspended ceiling 10 may be a rectangular flat plate shape. In this case, the suspended ceiling 10 is composed of a lower surface 10b and a plurality of struts (not shown) that fix the lower surface 10b to the ceiling plate 5c of the car 5. These struts are preferably provided at 4 corners of the suspended ceiling 10. A lighting device 5e (see fig. 2), an emergency speaker 5g (see fig. 2), and a speaker system 22 of the sound system 13 (see fig. 6) are provided in the internal space of the suspended ceiling 10. In the above description, the sound field control device 21 is described as being provided on the upper surface of the ceiling plate 5c of the car 5 as shown in fig. 1, but the sound field control device 21 may be disposed in the internal space of the suspended ceiling 10. A gap 11 (see fig. 2 and 6) is provided between the side surface 10a of the suspended ceiling 10 and the side plate 5a of the car 5. Hereinafter, the certain distance D is referred to as 1 st distance D.

In the example of fig. 1, the case where the elevator 1 is a rope elevator is shown, but the present invention is not limited to this case. The elevator 1 may be another type of elevator such as a linear elevator.

Fig. 2 is a diagram showing a state of an inner space of the car 5 of the elevator 1 according to embodiment 1. As shown in fig. 2, the inner space of the car 5 is surrounded by 4 side plates 5a, a floor 5b, and a lower surface 10b of the suspended ceiling 10. The inner space of the car 5 is, for example, rectangular parallelepiped. The floor 5b is constituted by a rectangular plane provided in the horizontal direction. Each side plate 5a is constituted by a rectangular plane provided in the vertical direction. Here, the vertical direction is, for example, the vertical direction. The lower surface 10b of the suspended ceiling 10 is disposed to face the floor 5 b. The lower surface 10b of the suspended ceiling 10 is constituted by a rectangular plane provided in the horizontal direction. The suspended ceiling 10 is provided with a lighting device 5e. The main body of the lighting device 5e is provided in the internal space of the suspended ceiling 10. The lighting device 5e is, for example, an LED lighting device. As shown in fig. 2, the irradiation surface 5ea of the illumination device 5e faces the floor 5 b. The illumination device 5e illuminates the inner space of the car 5 with light irradiated from the irradiation surface 5 ea. Further, the suspended ceiling 10 is provided with an emergency speaker 5g for playing emergency communication from the building management room. The emergency speaker 5g is used not only for playing emergency contact but also for playing a voice message for a user such as "door close".

As described above, the car door 5d is provided to the front side plate 5a of the 4 side plates 5 a. As shown in fig. 2, a car operating panel 5f is provided on the front side plate 5 a. The car operation panel 5f is provided with a plurality of car call registration buttons provided corresponding to the floors and a door opening/closing button for controlling the opening/closing operation of the car door 5d. Further, the car operating panel 5f is provided with an intercom device 5h for allowing a user to communicate with the outside in an emergency or the like.

As shown in fig. 2, the car control device 9 is connected to the elevator control panel 7 via a control cable 8 (see fig. 1), for example. As shown in fig. 2, the car control device 9 includes an input unit 9a, a control unit 9b, an output unit 9c, and a storage unit 9d. The input unit 9a inputs a control signal from the elevator control panel 7 to the control unit 9b. The control unit 9b performs operation control of each device provided in the car 5 based on the control signal. The output unit 9c outputs a drive signal to each device under the control of the control unit 9b. The output unit 9c transmits a signal such as a car call registration input from the user to the car operation panel 5f to the elevator control panel 7 under the control of the control unit 9b. The storage unit 9d stores the calculation result of the control unit 9b, various data and programs used for the control of the control unit 9b, and the like.

The sound field control device 21 is one of the constituent elements of the sound system 13. The sound system 13 is constituted by a sound field control device 21 and a speaker system 22 (see fig. 6) described later. As shown in fig. 2, the sound field control device 21 has a sound field control section 21a, an output section 21b, a storage section 21c, and a timer section 21d. The sound field control unit 21a controls the operation of the sound system 13 to form a sound field with high sound quality in the inner space of the car 5. The output unit 21b transmits the drive signal and reproduction data of the sound signal to the speaker box 20 (see fig. 6) under the control of the sound field control unit 21 a. The storage unit 21c stores, for example, sound content 30 (see fig. 4) obtained by mixing natural environment sounds representing sounds generated in the natural world with chord serial sounds based on combinations of harmony and non-harmony. The storage unit 21c also stores the calculation result of the sound field control unit 21a, various data and programs used for controlling the sound field control unit 21a, and the like. The sound field control unit 21a reproduces the sound content 30 stored in the storage unit 21c, and radiates a sound signal based on the sound content 30 from the speaker system 22 to the inner space of the car 5. The timer 21d counts the current date and time, and holds the current date and time data. The timer unit 21d has data of the month and day of the year and data of the time of day in the year as date-and-time data. The sound field control unit 21a may acquire date and time data from the timer unit 21d, and switch the sound content 30 according to seasons and life time based on the date and time data.

The audio content 30 stored in the storage unit 21c is generated by the audio content generating device 40 provided outside, for example, and stored in the storage unit 21c of the sound field control device 21 in advance. The sound content generating apparatus 40 combines the natural environment sound 30A (see fig. 4) and the chord serial sound 30B (see fig. 4) to generate the sound content 30.

[ Sound content Generation device 40]

Fig. 3 is a block diagram showing the configuration of an audio content generating apparatus 40 that generates audio content 30 used in the audio system 13 according to embodiment 1. Fig. 4 is an explanatory diagram illustrating the structure of the audio content 30 used in the audio system 13 according to embodiment 1. In fig. 4, the horizontal axis shows time and the vertical axis shows sound pressure level. The sound content 30 is generated by the sound content generating device 40, for example. The sound content 30 includes a natural environment sound 30A and a chord serial sound 30B. The natural environmental sound 30A is a sound representing environmental sounds generated in nature. The chord serial tone 30B is a sound composed of a combination of chords including a chord and a non-chord. The sound content 30 is formed by mixing the natural environment sound 30A and the chord serial sound 30B. That is, the sound content 30 is constituted by adding the chord serial 30B to the natural environment sound 30A. The natural environment sound 30A and the chord serial sound 30B are radiated from the speaker system 22 into the car 5 at the same time. The example shown in fig. 4 is an example showing the time change of each of the natural environment sound 30A and the chord serial sound 30B, and shows an example of the time waveform before mixing the natural environment sound 30A and the chord serial sound 30B.

As shown in fig. 3, the sound content generating apparatus 40 has an input section 41, a natural environment sound generating section 42, a chord serial sound generating section 43, a signal processing section 44, a mixing processing section 45, an output section 46, and a storage section 47.

The input section 41 has a1 st input section 41a and a2 nd input section 41b. The 1 st input unit 41a receives material data representing natural environmental sounds of sounds generated in nature from an externally provided recorder (not shown), a memory (not shown), or a sound material database 60. The material data of the natural environment sound may be any of recording data obtained by recording a sound actually generated in the natural world or pseudo data obtained by artificially generating a sound generated in the natural world. The audio data of the harmony and the non-harmony are input to the 2 nd input unit 41b from an external musical instrument (not shown) or the audio material database 60. The sound material database 60 is a database storing various sound materials such as recording data obtained by recording sounds actually generated in nature, dummy data obtained by artificially generating sounds generated in nature, effect sounds, chords, and human sounds.

The natural-environment-sound generating unit 42 generates the natural environment sound 30A using the material data of the natural environment sound input to the 1 st input unit 41 a. As shown in fig. 4, the natural environment sound 30A includes a natural background sound (hereinafter referred to as a natural BG sound) 31 and an additional sound 32 added to the natural BG sound 31. The natural BG sound 31 is a sound generated according to the state of the environment in the natural world. The natural BG sound 31 includes at least one of a sound of a tree swinging with the wind, a sound of water flowing in a river or sea, a loud sound, and a moving sound of an artificial object such as a car or an electric car. The additional sound 32 is a sound generated according to the behavior of living beings in nature. The additional sound 32 includes at least one of 1 or more bird song, 1 or more bird wing song when flying, 1 or more bird song when flying, 1 or more insect song, 1 or more animal song, and a human voice. The natural environment sound generation unit 42 adds the additive sound 32 to the natural BG sound 31 according to a preset timing adjustment rule. The timing adjustment rule is stored in the storage section 47. The storage unit 47 may store 2 or more timing adjustment rules. In this case, the timing adjustment rule to be used is selected by the user from among 2 or more timing adjustment rules. Alternatively, the timing of adding the additive sound 32 to the natural BG sound 31 may be input by the user operating the sound content generating apparatus 40 without using the timing adjustment rule of the storage section 47. As shown in fig. 4, the natural BG sound 31 is set to radiate continuously over the entire time length L of the natural environment sound 30A. The overall time length L of the natural environment sound 30A is set to 2 minutes or less. The additive sound 32 is set separately for each time zone 35 in which the time length L is divided into a plurality of time zones. Therefore, each time zone 35 has a time length set in accordance with the timing adjustment rule. The sound pressure level of the additional sound 32 is greater than that of the natural BG sound 31. The sound pressure level of the additional sound 32 is set to be larger than that of the natural BG sound 31 according to a preset sound pressure adjustment rule. The sound pressure adjustment rule is stored in the storage unit 47. The storage unit 47 may store 2 or more sound pressure adjustment rules. In this case, the user selects a sound pressure adjustment rule to be used from among 2 or more sound pressure adjustment rules. Alternatively, the sound pressure level of the natural BG sound 31 and the additive sound 32 may be input by the user operating the sound content generating device 40 without using the sound pressure adjustment rule of the storage unit 47.

The chord serial tone generating section 43 generates the chord serial tone 30B using the sound data of the harmony and the non-harmony inputted to the 2 nd input section 41B. The chord serial tone 30B is composed of a combination of a chord 33 and a non-chord 34. Fig. 5 is an explanatory diagram illustrating the structure of the chord serial 30B included in the sound content 30 used in the sound system 13 of embodiment 1. The chord serial tone 30B is generated by the chord serial tone generating section 43 provided in the sound content generating device 40. As shown in fig. 5, the chord serial tone 30B is configured such that the chord 33 and the chord 34 are alternately arranged in order, for example, as the chord 33→the chord 34→the chord 33. The length of time L1 of the harmony 33 is the same as the length of time L2 of the non-harmony 34 or longer than the length of time L2. Next, an example of time allocation of the time length L1 of the harmony 33 and the time length L2 of the non-harmony 34 is shown. However, the time allocation is not limited to the following example, and may be appropriately determined as an arbitrary allocation.

(A) Let the time length L1 of the harmony 33 be 2 seconds, and let the time length L2 of the non-harmony 34 be 1 second.

(B) The time length L1 of the harmony 33 is set to 3 seconds, and the time length L2 of the non-harmony 34 is set to 1 second.

(C) Let the time length L1 of the harmony 33 be 2 seconds, and let the time length L2 of the non-harmony 34 be 2 seconds.

(D) The time length L1 of the harmony 33 is set to 1 second, and the time length L2 of the non-harmony 34 is set to 1 second.

Thus, the harmony 33 and the non-harmony 34 are alternately arranged according to a predetermined time allocation rule. The time allocation rule is stored in the storage section 47. As described in (a) to (d), the storage unit 47 stores 2 or more time allocation rules. The user selects a time allocation rule to be used from among these time allocation rules. The time length L of the entire chord serial tone 30B is set to 2 minutes or less. Since the chord serial tone 30B is repeatedly reproduced, as shown in the example of fig. 5, when the chord at the beginning of the chord serial tone 30B is the chord 33, the chord at the end of the chord serial tone 30B is the chord 34. In contrast, in the case where the chord at the beginning of the chord serial tone 30B is the non-chord 34, the chord at the end of the chord serial tone 30B is made the chord 33. Thus, in the case of repeatedly cyclically reproducing the chord serial tone 30B, the chords 33 or the non-chords 34 can be prevented from being juxtaposed with each other at the joint portion. Therefore, the harmony 33 and the non-harmony 34 are also sequentially arranged at the joint portion.

The signal processing section 44 performs 1 or more signal processes on the natural environment sound 30A generated by the natural environment sound generating section 42 and the chord serial sound 30B generated by the chord serial sound generating section 43, as necessary. The timing of performing the signal processing may be before or after the mixing processing by the mixing processing unit 45. The signal processing unit 44 may perform signal processing on only one of the natural environment sound 30A and the chord serial sound 30B. The signal processing includes a plurality of processes such as generation of the preamble section 36 and the like, adjustment of sound pressure level, and phase control processing, which will be described later. This signal processing is described later.

The mixing processing section 45 performs mixing processing on the natural environment sound 30A and the chord serial sound 30B, thereby generating the sound content 30. The mixing processing section 45 performs mixing processing on the natural environment sound 30A and the chord serial sound 30B according to a synchronization timing adjustment rule set in advance. The synchronization timing adjustment rule is stored in the storage section 47.

Here, a hardware configuration of the car control device 9 will be described. The functions of the input unit 9a, the control unit 9b, and the output unit 9c in the car control device 9 are realized by a processing circuit. The processing circuitry is comprised of dedicated hardware or processors. The dedicated hardware is, for example, ASIC (Application SPECIFIC INTEGRATED Circuit) or FPGA (Field Programmable GATE ARRAY field programmable gate array). The processor executes programs stored in the memory. The storage unit 9d is constituted by a memory. The Memory is a nonvolatile or volatile semiconductor Memory such as RAM (Random Access Memory: random access Memory), ROM (Read Only Memory), flash Memory, EPROM (Erasable Programmable ROM: erasable programmable Read Only Memory), or a disk such as a magnetic disk, a floppy disk, or an optical disk.

The hardware configuration of the sound field control device 21 will be described. The functions of the sound field control section 21a, the output section 21b, and the timer section 21d in the sound field control apparatus 21 are realized by a processing circuit. The processing circuitry is comprised of dedicated hardware or processors. The dedicated hardware and processor may be the same as those described above, and thus description thereof is omitted. The storage unit 21c is constituted by a memory. The memory may be the same as that described above, and thus an explanation is omitted.

The hardware configuration of the audio content generating apparatus 40 will be described. The functions of the input unit 41, the natural environment sound generation unit 42, the chord serial sound generation unit 43, the signal processing unit 44, the mixing processing unit 45, and the output unit 46 in the sound content generation device 40 are realized by processing circuits. The processing circuitry is comprised of dedicated hardware or processors. The dedicated hardware and processor may be the same as those described above, and thus description thereof is omitted. The storage section 47 is constituted by a memory. The memory may be the same as that described above, and thus an explanation is omitted.

The software configuration of the sound material database 60 and the sound content generating apparatus 40 may be configured by virtual singer software to which a singing voice synthesizing technique such as Vocaloid (registered trademark) is applied, for example.

Fig. 6 is a front view showing the structure of the sound system 13 of embodiment 1. Fig. 7 is a plan view showing the arrangement of the speaker box 20 of the sound system 13 of embodiment 1. Fig. 7 shows a state in which the suspended ceiling 10 of the car 5 is seen from the floor 5b side of the car 5. In fig. 6 and 7, the height direction of the car 5 is defined as the Y direction, the width direction of the car 5 is defined as the X direction, and the depth direction of the car 5 is defined as the Z direction. The Y direction is, for example, the vertical direction. As shown in fig. 7, when the right and left directions in the car 5 are defined, the X direction is the right and left direction of the car 5, and the Z direction is the front and rear direction of the car 5.

As shown in fig. 6, the sound system 13 is composed of a speaker system 22 and a sound field control device 21, which are disposed on the ceiling of the closed space. The speaker system 22 includes 1 or more speaker boxes 20. In addition, 1 or more speaker units 23 are mounted on each speaker box 20. The sound system 13 forms a sound field 27 for the user of the car 5, and radiates sound. In embodiment 1, for example, as the sound, a sound content 30 is used in which a natural environment sound 30A naturally occurring in nature such as a river running sound and a bird song, and a chord serial sound 30B based on a combination of a chord 33 and a non-chord 34 are mixed. In embodiment 1, a sound field environment having 2 or more channels of reproduction is created in a closed space, and sound content 30 is reproduced in the sound field environment. Thus, the sound content 30 can be radiated from a plurality of directions to the closed space, and a "pleasant sensation" can be given to the auditory sensation of the user in the closed space. As a result, unpleasant factors such as pressure during retention in a narrow space can be reduced.

The natural environment sound 30A constituting the main body of the sound content 30 is constituted such that, for example, if it is a domestic living person in japan, it is possible to feel from sound a season such as spring, summer, autumn, winter, etc., and life time periods such as dawn, daytime, evening, nighttime, etc., in which the person can feel. Thus, even if the user uses a closed space in which the external environment cannot be seen, the user can obtain the sense of time and the sense of season from the "sound". In addition, the natural environment sound 30A does not have a loud feeling or the like, and does not have an unpleasant feeling in terms of hearing due to a content structure excluding unpleasant factors such as noise. Specifically, the natural environment sound 30A is composed of a composite combination of a sound source type, a time zone, and a frequency band, such as a flow of wind or river, or bird sound, which naturally occurs in the natural world.

In embodiment 1, as shown in fig. 6, the number of speaker boxes 20 included in the speaker system 22 is 2. However, the number of speaker boxes 20 is not limited to this, and may be any number of 2 or more. Thereby, a sound field 27 of 2 channels or more can be formed in the closed space. As shown in fig. 6, each speaker box 20 is provided in the internal space of the suspended ceiling 10. However, the speaker box 20 may be provided in at least one of the ceiling plate 5c of the car 5, the side plate 5a of the car 5, and the floor 5b of the car 5, not limited to the interior of the suspended ceiling 10. Each speaker box 20 is constituted by a speaker unit 23 and a housing 25. In embodiment 1, the speaker system 22 is described as including the speaker box 20, but the present invention is not limited to this case. That is, the speaker system 22 may include not the speaker box 20 but only 1 or more speaker units 23. In embodiment 1, the speaker unit 23 and the speaker box 20 are disposed on the suspended ceiling 10, but the present invention is not limited to this case. That is, the speaker unit 23 and the speaker box 20 may be disposed at other positions such as the side plate 5a of the car 5. In the above description, the number of the speaker boxes 20 provided in the car 5 is arbitrary 2 or more, but the present invention is not limited to this case. That is, the number of speaker boxes 20 and the number of speaker units 23 provided in the car 5 may be any number of 1 or more, and these numbers may be appropriately determined according to the volume, use, and the like of the car 5.

Fig. 8 is a side view showing an example of the structure of the speaker box 20 according to embodiment 1. Fig. 9 is a front view showing the structure of the speaker box 20 of fig. 8. As shown in fig. 8 and 9, the speaker box 20 is constituted by a speaker unit 23 and a housing 25. The speaker unit 23 is housed in a case 25. The speaker unit 23 has a radiation surface 23a provided on the front surface 25a of the housing 25 and radiating sound to the outside. The case 25 has, for example, a rectangular parallelepiped shape. The housing 25 is a hollow enclosure. The radiation surface 23a of the speaker unit 23 is fitted into a mounting hole provided in the front surface 25a of the housing 25, and is exposed to the outside through the mounting hole. The other portions of the speaker unit 23 are all disposed in the housing 25. Therefore, the sound from the radiation surface 23a of the speaker unit 23 is radiated only in the direction of arrow a in fig. 8, and is not radiated to the outside through other portions of the housing 25 than the radiation surface 23a.

Fig. 10 is a side view showing a structure of a modification of the speaker box 20 of embodiment 1. Fig. 11 is a front view showing the structure of the speaker box 20 of fig. 10. As shown in fig. 10 and 11, the speaker box 20 may house 2 or more speaker units 23 in the case 25. In this case, for example, one speaker unit 23-1 may be set as a full-range speaker, and the other speaker unit 23-2 may be set as a tweeter. The full-band speaker is a speaker that reproduces a frequency from a low frequency to a high frequency by using 1 speaker. In embodiment 1, when 1 speaker unit 23 is housed in the case 25 of the speaker box 20, the speaker unit 23 is a full-range speaker. The tweeter is a speaker dedicated to low frequencies, which is used as an auxiliary of the full-range speaker. It is assumed that it is difficult to reproduce sound quality from low frequency to high frequency with 1 speaker. In this case, a tweeter is used for compensating for this. The 2 or more speaker units 23 disposed in the housing 25 may use speakers of different types, or may use speakers of the same type. However, it is preferable to use 1 speaker as a full-range speaker, and use the other speaker as a low-frequency dedicated or high-frequency dedicated speaker serving as an auxiliary of the full-range speaker. In this case, it is possible to cope with a wide frequency band from a low frequency to a high frequency, and to radiate sound for each small frequency band. In this way, in the case where 1 speaker box 20 has a plurality of speaker units 23, improvement of the sound quality and expansion of the reproduction band can be achieved by the speaker box 20 alone. As a result, a "high sound quality system" that can cover a wide frequency band can be easily obtained.

[ Indirect Acoustic radiation ]

The description of fig. 6 and 7 is returned. As shown in fig. 6 and 7, the speaker box 20 is disposed in the internal space of the suspended ceiling 10. The height of the suspended ceiling 10 in the Y direction (the height direction of the car 5) is, for example, about 5 cm. Therefore, as shown in fig. 3, the height H1 of the housing 25 of the speaker box 20 in the Y direction (the height direction of the car 5) is 5cm or less. Or the height H1 is in the range of 3cm to 20 cm. In this way, the height H1 of the housing 25 is limited by the height of the suspended ceiling 10 in the Y direction (the height direction of the car 5). As shown in fig. 6 and 7, the radiation surface 23a of the speaker unit 23 is disposed so as to face the side plate 5a of the car 5. The radiation surface 23a is disposed along the edge of the side surface 10a of the suspended ceiling 10. As shown in fig. 7, the radiation surface 23a is located in the same plane as the side surface 10a of the suspended ceiling 10. Therefore, the position of the radiation surface 23a in the X direction (the width direction of the car 5) coincides or substantially coincides with the position of the side surface 10a of the suspended ceiling 10 in the X direction. An opening is provided in the side surface 10a of the suspended ceiling 10 so as to be aligned with the radiation surface 23 a. The entire side surface 10a of the suspended ceiling 10 may be opened. Therefore, the sound radiated from the radiation surface 23a is not shielded by the side surface 10a of the suspended ceiling 10. As described above, the gap 11 of the 1 st distance D is provided between the side surface 10a of the suspended ceiling 10 and the side plate 5a of the car 5. The 1 st distance D is about 5 cm. The 1 st distance D is appropriately set in the range of 2cm to 20cm, preferably in the range of 3cm to 10cm in combination with the specification of the car 5 of the elevator 1. As shown in fig. 6 and 7, sound radiated from the radiation surface 23a of the speaker unit 23 is radiated in the arrow a direction. Then, the sound is reflected by the side plate 5a of the car 5 to become a reflected sound. As shown in fig. 6 and 7, the reflected sound travels in the direction of arrow B. As described above, in embodiment 1, the speaker unit 23 performs "indirect sound radiation" in which sound radiation is performed to the user by reflection of the side plate 5a of the car 5.

In embodiment 1, the radiation surface 23a of the speaker unit 23 is disposed so as to face the side plate 5a of the car 5 across the gap 11 having the 1 st distance D, and so as to be close to the side plate 5a of the car 5. As described above, the 1 st distance D is, for example, about 5 cm. Therefore, the sound radiated from the radiation surface 23a of the speaker unit 23 is reflected by the side plate 5a of the car 5 immediately after the radiation before the sound pressure level is reduced.

As shown in fig. 7, the speaker box 20 is disposed at a position on the rear side of the central portion in the Z direction (the depth direction of the car 5) of the suspended ceiling 10. The position of the speaker box 20 in the Z direction is not limited to this, and may be provided at the center of the suspended ceiling 10 in the Z direction, or may be provided at a position on the front side of the center of the suspended ceiling 10 in the Z direction. As shown in fig. 6, the speaker box 20 is disposed at the center of the suspended ceiling 10 in the Y direction (the height direction of the car 5). The position of the speaker box 20 in the Y direction is not limited to this, and may be a position above the central portion or a position below the central portion in the Y direction of the suspended ceiling 10.

The speaker unit 23 of one speaker box 20 provided in the 2 speaker boxes 20 shown in fig. 7 is referred to as a speaker unit 23R. The speaker unit 23 provided in the speaker box 20 is referred to as a speaker unit 23L. The speaker unit 23R and the speaker unit 23L are arranged separately from each other. The speaker box 20 accommodating the speaker unit 23R and the speaker box 20 accommodating the speaker unit 23L are disposed at a predetermined distance from each other with the center portion of the suspended ceiling 10 in the X direction as the center. This certain distance is referred to as the 2 nd distance D2. The 2 nd distance D2 is determined by the X-direction dimension of the car 5, the 1 st distance D, and the X-direction dimension of the housing 25. The speaker unit 23R and the speaker unit 23L are arranged with their back surfaces facing each other. Therefore, as shown in fig. 7, the radiation surface 23a of the speaker unit 23R is disposed so as to face the right side plate 5a of the car 5. On the other hand, the radiation surface 23a of the speaker unit 23L is disposed so as to face the left side plate 5a of the car 5. The radiation surfaces 23a of the speaker units 23R and 23L are disposed so as to face the space 11, respectively. The radiation surfaces 23a of the speaker units 23R and 23L are arranged in the same plane as the left and right side surfaces 10a of the suspended ceiling 10.

In the car 5 of the elevator 1, the user generally stands in the direction of the car door 5 d. Therefore, the sound radiated from the speaker unit 23R mainly reaches the right ear of the user, and the sound radiated from the speaker unit 23L mainly reaches the left ear of the user. Hereinafter, the sound radiated from the speaker unit 23R is referred to as "right-side sound", and the sound radiated from the speaker unit 23L is referred to as "left-side sound".

[ Direct Acoustic radiation ]

The arrangement orientation of the speaker box 20 is not limited to the case of fig. 6 and 7. Fig. 12 is a front view schematically showing a configuration of a modification of the audio system 13 of embodiment 1.

In fig. 12, 2 speaker units 23R-1 and 23L-1 are provided opposite to the floor 5b of the car 5. Therefore, as shown in fig. 12, the radiation surfaces 23a of the speaker units 23R-1 and 23L-1 are disposed so as to face the floor 5b of the car 5. The speaker box 20 housing the speaker unit 23R-1 and the speaker box 20 housing the speaker unit 23L-1 are disposed at a predetermined distance from each other with the center portion of the suspended ceiling 10 in the X direction as the center. This certain distance is referred to as 3 rd distance D3. The 3 rd distance D3 may be the same as or different from the 2 nd distance D2 shown in fig. 7.

As shown in fig. 12, the radiation surfaces 23a of the speaker units 23R-1 and 23L-1 are arranged in the same plane as the lower surface 10b of the suspended ceiling 10, respectively. Therefore, the position of each radiation surface 23a in the Y direction (the height direction of the car 5) coincides or substantially coincides with the position of the lower surface 10b of the suspended ceiling 10 in the Y direction. Further, the radiation surface 23a portions of the speaker units 23R-1 and 23L-1 are fitted into mounting holes provided on the lower surface 10b of the suspended ceiling 10. The radiation surfaces 23a of the speaker units 23R-1 and 23L-1 are exposed to the outside from the mounting holes, respectively. Therefore, the sound radiated from the radiation surfaces 23a of the speaker units 23R-1 and 23L-1, respectively, is not shielded by the lower surface 10b of the suspended ceiling 10.

As shown in fig. 12, sound radiated from the speaker units 23R-1 and 23L-1 is radiated from the radiation surface 23a in the arrow a direction. In this way, the speaker units 23R-1 and 23L-1 perform "direct sound radiation" in which sound radiation is directly performed from the suspended ceiling 10 to the user.

[ Combination of indirect Acoustic radiation and direct Acoustic radiation ]

Fig. 13 is a plan view schematically showing a configuration of another modification of the audio system 13 according to embodiment 1. Fig. 13 shows a state in which the lower surface 10b of the suspended ceiling 10 is viewed from the floor 5b side. In fig. 13, 4 speaker units 23R-1, 23R-2, 23L-1, 23L-2 are provided. In fig. 13, 2 speaker units 23R-2 and 23L-2 out of 4 speaker units 23R-1, 23R-2, 23L-1, 23L-2 are provided opposite to the side plate 5a on the front side of the car 5. The other 2 speaker units 23R-1 and 23L-1 are disposed opposite to the floor 5b of the car 5. Therefore, as shown in fig. 12, the radiation surfaces 23a of the speaker units 23R-1 and 23L-1 are disposed so as to face the floor 5b of the car 5.

This will be described in more detail. As shown in fig. 13, the front-side 2 speaker units 23R-2 and 23L-2 are provided opposite to the front-side plate 5a of the car 5. The speaker box 20 accommodating the speaker unit 23R-2 and the speaker box 20 accommodating the speaker unit 23L-2 are disposed apart from each other by a predetermined distance with the center portion of the suspended ceiling 10 in the X direction as the center. The fixed distance may be the same as or different from the 3 rd distance D3 shown in fig. 12, for example.

Accordingly, the radiation surfaces 23a of the speaker units 23R-2 and 23L-2 are disposed so as to face the side plate 5a of the car 5, respectively. The radiation surfaces 23a are arranged along the sides of the side surfaces 10a of the suspended ceiling 10. Therefore, the position of each radiation surface 23a in the Z direction (depth direction of the car 5) coincides or substantially coincides with the position of the side surface 10a of the suspended ceiling 10 in the Z direction.

As described above, the gap 11 of the 1 st distance D exists between the side plate of the suspended ceiling 10 and the side plate 5a of the car 5. As shown in fig. 13, sound radiated from the speaker units 23R-2 and 23L-2 is radiated from the radiation surface 23a in the arrow a direction. Then, the sound is reflected by the side plate 5a of the car 5 to become a reflected sound. As shown in fig. 13, the reflected sound travels in the direction of arrow B. In this way, the speaker units 23R-2 and 23L-2 perform "indirect sound radiation" that performs sound radiation from the suspended ceiling 10 to the user by using the reflection of the side plate 5a of the car 5.

On the other hand, as described using fig. 12, the 2 speaker units 23R-1 and 23L-1 on the rear side are provided opposite to the floor 5b of the car 5. Therefore, as described above, the 2 speaker units 23R-1 and 23L-1 on the rear side perform "direct sound radiation" in which sound radiation is directly performed from the suspended ceiling 10 to the user. In embodiment 1, as in the modification of fig. 13, the "indirect sound radiation" and the "direct sound radiation" may be mixed. In this case, in fig. 13, instead of the speaker units 23R-2 and 23L-2, the speaker units 23R and 23L shown in fig. 7 may be provided.

The speaker unit 23 may be provided at any place on the lower surface 10b of the suspended ceiling 10 in the car 5. As the installation mode, there are, for example, a case of being arranged on the right and left sides as shown in fig. 7, a case of being arranged on the front and rear sides, a case of being arranged on the corner and the corner of the lower surface 10b of the suspended ceiling 10, and the like, and combinations of these cases are also free. However, when the speaker units 23 are separated from each other to some extent, sound quality becomes good. Therefore, in embodiment 1, the speaker boxes 20 accommodating the speaker units 23 are arranged apart from each other by the 2 nd distance D2 or the 3 rd distance D3.

[ Height of speaker box 20)

A speaker box 20 is sometimes provided in the floor 5b of the car 5. However, the body itself of the user becomes a sound absorbing body and a reflecting body, and therefore, when the number of users increases, it is difficult for the sound signal radiated from the lower part of the user's feet to reach the position of the user's ears. As a result, the sound field 27 based on the sound reproduction with high quality cannot be produced in the car 5. Thus, in embodiment 1, in order to realize high-quality reproduction, the speaker box 20 is provided at a position substantially above the chest of the user. Therefore, the speaker box 20 is preferably provided on the suspended ceiling 10, the upper portion of the side plate 5a of the car 5, or the like.

[ Sound field 27]

The sound field 27 generated by the sound system 13 is, for example, the range shown by the broken line in fig. 6. Specifically, the height H2 of the lower limit 27a of the sound field 27 is, for example, about 1.0m to 1.8m, preferably about 1.6m to 1.8m, from the floor 5b of the car 5. The upper limit of the sound field 27 is, for example, 1.8m to 2.0m from the floor 5b of the car 5. Thus, the sound field 27 is preferably formed in a height range of 1.6m to 1.8m from the floor 5 b. In this way, the sound field 27 is generated in the car 5 at a portion above the lower limit 27 a. As a result, as shown in fig. 6, the sound field 27 is formed around the head of the user. The height H2 of the lower limit 27a of the sound field 27 is set according to the average height of the user (excluding middle school students). In addition, in the range of 0m to less than 1.6m from the floor 5b, as described above, when a plurality of users are riding in the car 5, the sound is shielded or absorbed by the body of the users, and therefore, a good sound field cannot be formed. Further, in a range where the height from the floor 5b exceeds 1.8m, the sound field 27 is formed so as to be biased toward the head of the user, and thus hearing by the user is difficult. The generation range of the sound field 27 is not limited to the case of being generated in the range of 1.6m to 1.8m. That is, since the sound field 27 may be generated in a range of not less than the chest of the user based on the average height of the user (excluding the middle school student), it is preferable that the height H2 of the lower limit 27a of the sound field 27 is in a range of, for example, 1.0m to 1.8m from the floor 5b of the car 5.

[ Structure of Sound content 30 ]

Next, the structure of the audio content 30 according to embodiment 1 will be described in detail with reference to fig. 4. The sound content 30 is sound data for reproducing the sound signal radiated from the speaker system 22 by the control of the sound field control section 21 a. As described above, the natural environment sound 30A and the chord serial sound 30B based on the combination of the chord 33 and the non-chord 34 are mixed to constitute the sound content 30. The upper segment of fig. 4 is a time waveform example of the natural environment sound 30A, and the lower segment of fig. 4 is a time waveform example of the chord serial sound 30B.

In the natural environment sound 30A shown in the upper stage of fig. 4, (1) to (3) are the additional sounds 32. Specifically, (1) is a sound of 1 or more animals, (2) is a sound of 1 or more birds, and (3) is a flying sound of 1 or more birds flying and a sound of 1 or more birds. In the natural environment sound 30A shown in the upper stage of fig. 4, (4) is a natural BG sound 31. Specifically, (4) includes at least one of a sound of a tree swinging with the wind, a sound of water flowing in a river or sea, a loud sound, a sound of a person, and a moving sound of an artificial object such as a car or an electric car. In this way, the natural BG sound 31 is set over the entire time length L of the sound content 30. On the other hand, the additional sound 32 is arranged at intervals.

In addition, in the upper and lower stages of fig. 4, (5) shows a state of fade-in of the sound content 30, and (6) shows a state of fade-out of the sound content 30. The "fade-in" means that the sound pressure level of the sound content gradually increases, and the fade-in process means that the sound pressure level of the sound content gradually increases. The "fade-out" means a process of gradually decreasing the sound pressure level of the sound content, and the fade-out process means a process of gradually decreasing the sound pressure level of the sound content. That is, the head of the audio content 30 is subjected to fade-in processing, and the tail of the audio content 30 is subjected to fade-out processing. Therefore, in the case of cyclically reproducing the sound content 30, the sound pressure level of the joint portions 30a (see fig. 14) of the sound content 30 is configured to be minimum.

As shown in fig. 5, the chord serial tone 30B shown in the lower stage of fig. 4 is configured such that the chord 33 and the non-chord 34 are alternately arranged in order with the lapse of time. As described using fig. 5, the time length L1 of the harmony 33 is greater than the time length L2 of the non-harmony 34. Further, one of the chords of the beginning and end of the chord serial tone 30B is constituted by the harmony tone 33, and the other is constituted by the incoordination tone 34.

In embodiment 1, the overall time length L of the audio content 30 (i.e., the audio signal) is set to be 2 minutes or less. That is, the time length L of the sound content 30 is at most 2 minutes (i.e., 120 seconds). The up-and-down movement time of the car 5 of the elevator 1 depends on the height of the building, but even in a high-rise building, the movement time of the car 5 is often about 2 minutes or less. The reason for this is as follows. The space in the car 5 is a closed space. Under the condition that the user is restrained in the closed space for a long time, the user is in an immovable state, and thus, the pressure state is continued. Further, since persons not recognized in the closed space are in a very close positional relationship with each other in the car 5, it can be said that a state is not preferable from the viewpoint of prevention of a crime. Therefore, the actual travel time of the car 5 of the elevator 1 is limited to 90 seconds or less in many cases, and is limited to 90 seconds to 120 seconds or less even in a super high-rise building. Thus, in embodiment 1, the time length L of 1 audio content 30 is set to be within 2 minutes, that is, within 90 seconds to 120 seconds. In the example of fig. 4, the time length L of the sound content 30 is set to 90 seconds. The sound field control unit 21a repeatedly and continuously reproduces the sound content 30 in the car 5 for 2 minutes or less. In this way, the repeatedly reproduced sound content 30 is generated so as to have the melody that varies in a certain period.

But also assumes the case of using the sound content 30 in an environment other than an elevator. In this case, the time length L of the sound content 30 may be longer than 2 minutes. However, in this case, one of the chords at the beginning and the chords at the end of the chord serial 30B is composed of the harmony 33, and the other is composed of the incoordination 34. Thus, when the sound content 30 is cyclically reproduced, the harmony 33 and the non-harmony 34 are connected at the joint portion 30a of the sound content 30.

In addition, when the sound content 30 is reproduced cyclically, a foreign sound (pop sound) is sometimes generated in the joining portion 30a of the sound content 30. Examples of the cause of the generation of the abnormal sound (pop) include the performance of a sound circuit or a data recording device for storing the sound content 30, and particularly the degradation of the data recording device for storing the sound content 30. Since the user in the car 5 is in a quiet environment, the abnormal sound (pop-up sound) is prominent and is easily heard, and may be perceived as a very unpleasant abnormal sound. In order to prevent unpleasant feeling caused by the abnormal sound (pop-up sound), in embodiment 1, the audio content 30 has the following structure.

Fig. 14 is an explanatory diagram schematically showing a time variation of the sound pressure level of the sound content 30 used in the sound system 13 of embodiment 1. Fig. 14 schematically shows the sound pressure level of the entire sound content 30 obtained by combining the sound pressure level of the natural environment sound 30A and the sound pressure level of the chord serial sound 30B of the sound content 30.

As shown in fig. 14, the sound content 30 is cyclically reproduced for a period of time equivalent to the time length L. In fig. 14, (5) shows a state of fade-in of the sound content 30, and (6) shows a state of fade-out of the sound content 30. As described above, the audio content 30 is subjected to the fade-in processing for gradually increasing the sound pressure level at the beginning of the reproduction start, and is subjected to the fade-in processing for gradually increasing the sound pressure level at the end of the reproduction end. Therefore, in the case of cyclically reproducing the sound content 30, as shown in fig. 14, (6) fade-out processing and (5) fade-in processing are performed at the joining portions 30a of the sound content 30 to each other. The length L3 of the engagement portion 30a is set to be within 3 seconds. In addition, in the fade-out processing, the sound pressure level of the sound content 30 is reduced by 6dB from the original sound pressure level. In the fade-in process, the sound pressure level of the sound content 30 reduced in the fade-out process is increased by 6dB, and the original sound pressure level is returned. The increase or decrease in sound pressure level is not limited to 6dB, and may be 6db±α (here, α is an arbitrary value).

By performing the fade-out processing in the joint portion 30a in this way, the sound pressure level of the sound content 30 is reduced by 6dB from the original sound pressure level, and thus, the abnormal sound (pop-up sound) generated in the joint portion 30a can be prevented from being heard by protruding. In addition, in a silent space of a general silent elevator, many users feel uncomfortable and unpleasant. In embodiment 1, the fade-out process and the fade-in process of the joint portion 30a are performed in total within 3 seconds, and thus, only the transient silence is obtained. Therefore, the user can be prevented from feeling unpleasant feeling felt in the silent space of a general elevator.

In general, the car 5 moves up and down and stops at a floor designated by a user according to a button operation by the user. During this time, the sound content 30 is repeatedly reproduced. Therefore, the user does not have to listen to the audio content 30 from the initial head of the audio content 30. According to the user, the elevator 1 may be used from a stage in the middle of the sound content 30 being reproduced. In addition, for example, there may be many cases where the user uses the elevator 1 in the movement of a plurality of floors, such as from 1 floor to 10 floors, but there may be cases where the user uses the elevator 1 in the movement of a plurality of floors, such as from 4 floors to 5 floors.

When a user uses the elevator 1 during movement of only 1 floor, the time required for the series of operations of "the user gets on the car 5" → "the car 5 moves" → "the car 5 stops" is generally 10 seconds or less. If ordinary music reproduction is performed in the car 5 at this time, the music reproduction does not end at 10 seconds, and thus the user is forced to interrupt listening to the music during the music reproduction. According to the user, even if the user likes the music and wants to further listen to the music, he must get off the car 5 at the floor designated by the user. In this case, the user is stressed instead. Thus, in embodiment 1, for example, the user who uses the elevator 1 during the movement of the floor 1 radiates the sound content 30 without giving stress or unpleasant feeling. Specifically, in order not to bring about stress and unpleasant feeling even in a short use time, music that is "meaningful sound" is not reproduced, but "natural environment sound 30A (sound generated in nature)" = "meaningless sound" that is not particularly meaningful is used. As described later, the "chord serial tone 30B" is different from general music in that only a series of sets of chords in which the chord 33 and the non-chord 34 are arranged side by side. Therefore, "chord serial tone 30B" is also "nonsensical sound". If the "meaningless sound" is reproduced, the possibility of stress to the user is extremely low if the user is forced to interrupt listening to the sound during the reproduction of the sound.

The chord serial tone 30B reduces the sound pressure level by 3dB to 6dB on average compared with the natural environment tone 30A. Therefore, the natural environment sound 30A becomes the main body of the sound content 30, and the chord serial sound 30B becomes the background sound (background sound) of the natural environment sound 30A. As described above, the natural environment sound 30A is obtained by adding the added sound 32 such as the bird song to the natural BG sound 31 such as the river water sound. Therefore, the natural environment sound 30A is easily broken due to the intensity of the sound pressure level. On the other hand, the chord serial tone 30B has a musical tone structure and musical interval based on a predetermined period. Therefore, even if the sound pressure level of the natural environment sound 30A temporarily becomes small, the chord serial sound 30B is always presented to the user at substantially the same sound pressure level.

[ Chord Serial tone 30B ]

Next, the structure of the chord serial 30B will be described. As described using fig. 5, the chord serial tone 30B is a set of a series of chords in which the chord 33 and the non-chord 34 are arranged in order. Next, the harmony 33 and the non-harmony 34 are explained.

Fig. 15 is a basic explanatory diagram of the harmony sound 33 and the harmony sound 34 used in the sound system 13 of embodiment 1. As shown in fig. 15, the harmony 33 and the harmony 34 forming the chord serial tone 30B are chords composed of tones within 1 octave, respectively.

As shown in fig. 15, regarding the basic chord, the suffix of "degree" is used to indicate stepwise how far apart 2 tones are. Hereinafter, 2 tones are referred to as "down tone" and "up tone". In fig. 15, "degree" is used to indicate "upper pitch" when "lower pitch" is "do". The height of the same tone is referred to as "full 1 degree" or "same degree", the width of 1 semitone is referred to as "short 2 degrees", and the width of 2 semitones is referred to as "long 2 degrees". In the same manner, the width of 3 semitones is referred to as "short 3 degrees", and the width of 4 semitones is referred to as "long 3 degrees". In addition, the width of 12 semitones is referred to as "full 8 degrees" or "octave". Therefore, as shown in fig. 15, when "do" on the lower side is set as "downsound", the "re" is referred to as "2 degrees long", the "mi" is referred to as "3 degrees long", and the "do" on the upper side is referred to as "full 8 degrees". Fig. 16 is an explanatory diagram showing the relationship between "down" and "up" constituting the chord used in the sound system 13 of embodiment 1, using a list of "degrees".

In the case where more than 2 tones are simultaneously generated, any one of the harmonized state and the non-harmonized state is generated. The chord 33 is a chord in a synergetic state in which 2 or more simultaneous harmony notes are generated. The incoordination 34 is a chord in an incoordination state in which 2 or more incoordinations are simultaneously generated. However, there is no clear division between the coordination state and the non-coordination state, and the degree of coordination between 2 tones becomes an important element. The human ear has the following properties: in psychology, the closer the ratio of the vibration numbers (frequencies) of "down" and "up" is to a simple integer ratio, the more the sound is to be cooperated, and the more the ratio of the vibration numbers (frequencies) is to be a complex ratio, the more the non-cooperated sound is to be heard. Fig. 17 is a diagram showing an example of the definition of the harmony sound 33 and the harmony sound 34 used in the sound system 13 of embodiment 1. As shown in fig. 17, the harmony sound 33 includes, for example, a full 1 degree, a full 8 degrees, a full 5 degrees, a full 4 degrees, a long 3 degrees, a short 3 degrees, a long 6 degrees, and a short 6 degrees. Further, the non-chord 34 includes, for example, 2 degrees long, 2 degrees short, 7 degrees long, 7 degrees short, and the like. Fig. 18 and 19 are diagrams showing an example of the harmony sound 33 used in the audio system 13 according to embodiment 1. Fig. 20 is a diagram showing an example of the mismatch 34 used in the audio system 13 according to embodiment 1. In embodiment 1, the harmony 33 and the non-harmony 34 to be used are appropriately selected from these harmony 33 and non-harmony 34 to be used. Then, the selected chord 33 and the non-chord 34 are alternately configured, thereby generating the chord serial tone 30B.

Unlike the harmony 33, the non-harmony 34 is different from the harmony 33 in that the ratio of the vibration numbers (frequencies) is not an integer ratio. That is, the non-consonant 34 contains frequency components where one tone is not an integer multiple of the frequency of the other tone. Thus, the incoordination 34 can cause a change in sound quality. In the chord serial tone 30B, the chord 33 and the non-chord 34 are alternately reproduced. Accordingly, the user alternately listens to a certain period of sound quality based on the harmony 33 and to the sound quality causing the period change based on the non-harmony 34, whereby the change in hearing can be perceived. As a result, the cocktail effect is obtained, and the user's consciousness is focused on the chord serial tone 30B, thereby reducing unpleasant factors such as stress. The cocktail effect is an effect of enabling an unintentional selection of only brains from surrounding environmental sounds to listen to information on themselves or information of interest. The human brain has the following screening capacity: as in the cocktail party, in the gathering of the plurality of people talk and laugh, although the surrounding noise level is very high, only the voice of the partner who is engaged in the conversation can be naturally discriminated. The screening capacity is a cocktail party effect.

The chord serial tone 30B allows the user to feel a change in hearing by inserting the non-harmony 34 in the harmony tone 33. As a result, once the user is aware of the existence of the chord serial 30B, the consciousness is thereafter concentrated on the chord serial 30B due to the cocktail effect. Therefore, the user listens to the chord serial sound 30B in the subconscious sense, and thus the consciousness of being located in the closed space such as the car 5 of the elevator is weakened. As a result, the user's uncomfortable feeling and unpleasant feeling are reduced.

In addition, in general, the generation of the incoordination sound causes a person to feel "tension" of anxiety or excitement, and the generation of the incoordination sound causes a person to feel "relaxation" of silence or calm mood. When the 'loose' state is always continuous, the person feels boring, and the cocktail effect is not generated. Therefore, in the chord serial tone 30B of embodiment 1, the "tension" of the non-chord 34 is inserted in the "relaxation" of the harmony tone 33. That is, the chord serial tone 30B is constituted by repetition of "slackening" and "tension". The user generates "relaxation" after the "tension" generated from time to time, and thereby releases from the "tension" to feel happy mood. As a result, the user can feel the expansion of the sound, and can feel the feeling of openness, refreshing, and pleasure.

Fig. 21 is an explanatory diagram showing an example of the characteristics of the frequency band used as the chord serial tone 30B used in the sound system 13 of embodiment 1. In fig. 21, the horizontal axis shows frequency, and the vertical axis shows sound pressure level. In fig. 21, a thick line 50 shows the main frequency band of the chord serial 30B, and a thin line 51 shows the sub-frequency band of the chord serial 30B.

As shown by the thick line 50 in fig. 21, the chord serial tone 30B sets a frequency band of approximately 100Hz or more and less than 800Hz as a main frequency band. Therefore, the frequency of the chord serial tone 30B becomes substantially the range of the main frequency band. As described above, the chord serial tone 30B is constituted of tones within 1 octave, whereby the frequency does not change greatly. The reason for this will be described. Regarding human auditory properties, auditory sensitivity is high for a frequency band higher than about 1 kHz. Therefore, when the frequency of the chord serial sound 30B is changed greatly from the low frequency band to the high frequency band, the user only hears the sound of the high frequency, and the natural environment sound 30A is not easily heard. In this case, the harmony of the natural environment sound 30A and the chord serial sound 30B disappears. As a result, the user is provided with an audible unpleasant sensation. Therefore, in embodiment 1, the chord serial tone 30B basically uses the main frequency band, and the frequency does not change greatly. As a result, the harmony of the natural environment sound 30A and the chord serial sound 30B is ensured.

In addition, when it is desired to change the chord serial tone 30B for some reason, the chord serial tone 30B may partially use a sub-band of the frequency band of 800Hz to 2 kHz. In addition, when the sub-band is used for the chord serial tone 30B, the time length of the sound is set to a short time of 2 seconds or less, and the auditory cocktail effect is not easily caused, but the auditory function based on the melody as a musical tone remains.

[ Natural environmental Sound 30A ]

Next, the structure of the natural environment sound 30A will be described. As described using fig. 4, the natural environment sound 30A is formed by adding an additional sound 32 such as a bird song to a natural BG sound 31 such as a river water sound. The natural environmental sound 30A is composed of an environmental sound obtained by combining sounds from a plurality of sound sources existing in nature. The sound source of the environmental sound may be an artificially created sound source.

The sound source structure is, for example, as follows.

(1): Ringing sound of more than 1 animal

(2): Ringing sound of more than 1 bird

(3): Flying sound when more than 1 bird flies

(4): Including at least one of a sound of a tree swinging with the wind, a sound of water flowing in a river or sea, a loud sound, a sound of a person, and a moving sound of an artificial object such as a car or an electric car.

The sound sources (1) to (3) of the sound sources are sound sources constituting the natural BG sound 31 of fig. 4, and are sound for a user to imagine an environment state in nature. Sound sources (1) to (3) are sound sources of environments in nature (hereinafter referred to as 1 st sound source). The sounds of the sound sources (1) to (3) are sounds generated from the 1 st sound source, that is, sounds based on the environmental state of the natural world. On the other hand, the sound of the sound source (4) is a sound constituting the additional sound 32 of fig. 4, and is a sound for the user to imagine the behavior of living things in nature. The sound source (4) is a sound source (hereinafter referred to as the 2 nd sound source) of living beings and the like inhabiting in the natural world. The sound of the sound source (4) is a sound generated from the 2 nd sound source, that is, a sound based on the behavior of living beings in the natural world.

The time periods 35 constituting the natural environment sound 30A are not all the same, but are set to be at least 2 time periods. That is, the time interval 35 may be set to 2 time periods such as 2 seconds, 3 seconds, 5 seconds, 8 seconds, and the like.

The natural BG sound 31 is set to radiate continuously throughout the plurality of time intervals 35. The additive sound 32 is set individually for each time zone 35, and is radiated for each time zone 35. The additional sound 32 has a higher sound pressure level than the natural BG sound 31. The difference between the sound pressure level of the additional sound 32 and the sound pressure level of the natural BG sound 31 is 10dB or more. Further, too large a difference in sound pressure level gives an unpleasant feeling to the user, and therefore the upper limit is set to about 20 dB. In this way, in embodiment 1, the sound pressure level of the additive sound 32 is set to be greater than that of the natural BG sound 31 in the range of +10dB to +20dB (instantaneous). Thus, the additive sound 32 is presented as a signal having a clear sound pressure level with respect to the natural BG sound 31.

As shown in the example of fig. 4, the additional sound 32 is not set for all the time zones 35, and the time zone 35 in which the additional sound 32 is not set is also set. In the example of fig. 4, a time zone 35 (hereinafter referred to as "1 st time zone") in which the additional sound 32 is added and a time zone 35 (hereinafter referred to as "2 nd time zone") in which the additional sound 32 is not added are provided. The reason for this is that when the additional sound 32 is provided for all the time intervals 35, the user is highly likely to be given an impression of "noisy". In embodiment 1, in order to give the user an impression of "pleasure", each time zone 35 is arranged such that at least one of the adjacent time zones 35 is the 2 nd time zone of "no additional sound". That is, at least 1 "no additional sound" 2 nd time zone is arranged between adjacent "additional sound" 1 st time zones. On the other hand, 2 or more "no additional sound" 2 nd time intervals may be arranged in succession.

Further, the natural environment sound 30A has a pre-playing portion 36 including 1 or more time intervals 35, a post-playing portion 38 including 1 or more time intervals 35, and an intermediate playing portion 37 set between the pre-playing portion 36 and the post-playing portion 38 and including 1 time interval 35. In the example of fig. 4, the prelude portion 36 contains 4 time intervals 35, the middle portion 37 contains 1 time interval 35, and the postamble portion 38 contains 4 time intervals 35. The number of these time intervals 35 is merely an example, and is not limited thereto. Further, the intermediate playing section 37 is illustrated as including 1 time zone 35, but the intermediate playing section 37 may include 2 or more time zones 35.

In addition, the time zone 35 constituting the intermediate playing section 37 may have the longest time length among the plurality of time zones 35. Specifically, when the time length of the other time zone 35 is 2 seconds to 8 seconds, the time zone 35 constituting the intermediate playing section 37 may have a time length of about 15 seconds. Here, the time length of the time interval 35 having the largest time length among the plurality of time intervals 35 included in the prelude portion 36 is set to the 1 st time length. Further, the time length of the time interval 35 having the largest time length among the time intervals 35 included in the fingering portion 38 is set to be the 2 nd time length. At this time, when the time length of the time interval 35 included in the intermediate playing section 37 is set to be the 3 rd time length, the 3 rd time length may be set to be longer than the 1 st time length and the 2 nd time length.

In the car 5, the natural environment sound 30A including the additional sound 32 is reproduced together with the chord serial sound 30B, whereby it is possible to reduce the "tension feeling" which ensures unnecessary quietness that brings about the unique "uncomfortable feeling" in the elevator 1. Thus, the natural environment sound 30A of embodiment 1 utilizes the sound of the natural world. Further, a series of cue sounds of the natural environment sound 30A gradually change the intensity of the sound with time like the common music, like the pre-playing section 36→the intermediate playing section 37→the post-playing section 38. Specifically, it is preferable that the natural environment sound 30A maximizes the sound pressure level of the additional sound 32 in the intermediate playing section 37 and maximizes the time length of the additional sound 32.

Therefore, the maximum value of the sound pressure level of the additional sound 32 in the time interval 35 included in the preamble section 36 is set to level 1. Let the maximum value of the sound pressure level of the additional sound 32 in the time interval 35 contained in the accompaniment part 38 be level 2. Further, the maximum value of the sound pressure level of the additional sound 32 in the time interval 35 included in the intermediate playing section 37 is set to level 3. In this case, in embodiment 1, as shown in fig. 4, the 3 rd stage is set to be larger than the 1 st and 2 nd stages. In the example of fig. 4, the 3 rd stage is set to be about 1.5 to 4 times larger than the 1 st and 2 nd stages. Therefore, the user listens to the additional sound 32 with a larger sound pressure level in the intermediate playing section 37 after listening to the additional sound 32 with a smaller sound pressure level in the pre-playing section 36. In this way, the user receives the change in the intensity of the sound of the additional sound 32 with the temporal change, and thus does not hear the sudden sound change. As a result, the user can listen to the reproduced sound of the sound content 30 without being confused. In the above description, the maximum value of the sound pressure level of the additional sound 32 in the time zone 35 included in the intermediate section 37 is set to the 3 rd level, but the average value of the sound pressure levels of the additional sound 32 in the time zone 35 included in the intermediate section 37 may be set to the 3 rd level.

Next, the frequency bands of the natural BG sound 31 and the additive sound 32 will be described with reference to fig. 22 and 23. Fig. 22 is a graph showing instantaneous frequency characteristics when FFT (fast Fourier transform: fast fourier transform) processing is performed on the time waveform at the point (B) in fig. 4. That is, fig. 22 shows the instantaneous frequency characteristic of the additive sound 32. Fig. 23 is a diagram showing instantaneous frequency characteristics when FFT processing is performed on the time waveform at the point (a) in fig. 4. That is, fig. 23 shows the instantaneous frequency characteristics of the natural BG tone 31. In fig. 22 and 23, the horizontal axis shows frequency, and the vertical axis shows sound pressure level.

When comparing fig. 22 and fig. 23, in fig. 22, a large change can be observed in the frequency characteristic between 2000Hz and 10000 Hz. That is, in fig. 22, the sound pressure level in the frequency band between 2000Hz and 10000Hz is significantly higher than that in the other portions. On the other hand, in fig. 23, the frequency characteristics do not change greatly in any frequency band. That is, the change in frequency characteristics observed in fig. 22 indicates a characteristic change when the additive sound 32 is more than 10dB more prominent than the natural BG sound 31 as described above. By listening to the change in sound pressure level, the user reliably recognizes the sound of the frequency band in which the sound pressure level is changed, potentially having a posture in which the sound of the frequency band is to be listened to. As a result, the user concentrates on listening to the sound, and can cause a change in emotion.

In the example of fig. 22, the sound pressure level is changed in the frequency band between 2000Hz and 10000Hz, but the present invention is not limited to this case. That is, it is important to change the sound pressure level in a frequency band of 800Hz or more. The reason for this is that the frequency band that is easy to hear by a person is a frequency band of 800Hz or more and 15kHz (the range of the dotted line frame in fig. 22 and 23). By controlling the frequency of the frequency band, the user can pay attention to the sound and also utilize the physiological response of the sound to be listened to, and thus control can be performed in which the attention to the sound is increased. Therefore, in embodiment 1, the frequency of the additive sound 32 is set to 800Hz or more.

[ Signal processing in Signal processing section 44 ]

Next, the signal processing performed by the signal processing unit 44 will be described. The signal processing unit 44 performs the following signal processing on the natural environment sound 30A and the chord serial sound 30B included in the sound content 30. However, this signal processing is not necessarily required, and may be performed as needed.

[ Signal processing for Natural environmental Sound 30A ]

The natural BG sound 31 included in the natural environment sound 30A is not subjected to phase processing such as reverberation and sound image (panning). However, if the natural BG sound 31 is determined to be in a sound source state with a small auditory three-dimensional effect, signal processing may be performed. Specifically, at least one of the following 2 signal processes (i) and (ii) may be performed on the signal around the natural BG sound 31 to obtain a sense of expansion of the sound in the sense of hearing. Here, the sound radiated from the speaker unit 23R shown in fig. 7 is referred to as a "right signal", and the sound radiated from the speaker unit 23L shown in fig. 7 is referred to as a "left signal".

(I) A delay time of 300ms or less is set for one of the right signal and the left signal of the natural BG tone 31 so as to be delayed than the other.

(Ii) A gain difference in the range of ±3dB to 6dB is set for one of the right-side signal and the left-side signal of the natural BG tone 31 so as to be different from the other.

The signal processing (i) will be described. A delay time is set for the natural BG sound 31 of the right signal so that the natural BG sound 31 of the right signal is delayed from the natural BG sound 31 of the left signal. The delay time is appropriately set in a range of more than 0ms and 300ms or less. Thus, the sense of expansion of the sound can be deduced. In embodiment 1, the radiation timing of the signal on the left side is advanced from that of the signal on the right side, but the opposite may be adopted.

Next, the signal processing (ii) will be described. The gain difference is set for the sound pressure level of the signal on the right side so that the sound pressure level of the signal on the right side is greater than the sound pressure level of the signal on the left side. The absolute value of the difference between the sound pressure level of the signal on the right side and the sound pressure level on the left side is in the range of 3dB or more and 6dB or less. Thus, the sense of expansion of the sound can be deduced. In general, the ear on the right side is often the most favorable ear, and therefore, in embodiment 1, the sound pressure level on the right side is made larger than that on the left side, but the opposite may be also adopted.

Next, the signal processing performed on the additional sound 32 will be described with reference to fig. 24 to 27. Fig. 24 to 27 are explanatory diagrams illustrating an example of signal processing performed on the audio content 30 according to embodiment 1. Here, a case of processing the additional sound 32 is illustrated. In addition, these signal processing may be performed on the chord serial tone 30B. The case where these signal processes are performed on the chord serial tone 30B will be described later. In fig. 24, sound image processing of the left and right signals is being performed. In fig. 24, the horizontal axis shows time, and the vertical axis shows angle. Fig. 24 shows a case where sound image processing for making a user feel that the sound source moves from right to left is performed. In fig. 25, as signal processing, stereo expansion processing is being performed. In fig. 25, the horizontal axis shows time, and the vertical axis shows the proportion of stereoscopic expansion. Fig. 25 shows a case where the phase control process is performed in which the "spread" and the "sense of stenosis" are repeatedly obtained for the total time period of the audio content 30. Fig. 26 shows the original waveform before the reverberation processing of the additive sound 32 used in the sound system 13 of embodiment 1. Fig. 27 shows waveforms in which the reverberation processing of the additional sound 32 used in the sound system 13 of embodiment 1 is performed and the state in which the reverberation component is deleted from the original waveform of the additional sound 32. The signal processing shown in fig. 24 to 27 is performed on the additional sound 32 included in the natural environment sound 30A, as necessary.

As described above, the natural environment sound 30A performs signal processing such as sound image processing, stereo widening processing, and reverberation processing on the additional sound 32 as necessary. In the case of performing signal processing, the signal processing is performed based on the auditory sense, and at least one of the following 2 signal processing (iii), (iv) and (v) is performed.

(Iii) In the processing of the left and right signals of the additional sound 32, the range of 90 degrees to-90 degrees is freely changed within the total time length (for example, 90 seconds) of the sound content 30.

(Iv) In the stereo expansion processing of the left and right signals of the additional sound 32, the phase difference is freely changed within a range of 20% to 240% with respect to the left and right signals of the additional sound 32 within the total time length (for example, 90 seconds) of the sound content 30.

(V) In the reverberation processing of the left and right signals of the additional sound 32, the reverberation component is adjusted within a range of-100 ms to +100ms for the left and right signals of the additional sound 32. That is, the reverberation component is deleted from the original waveform of the additional sound 32, or the reverberation component is added to the original waveform of the additional sound 32.

The signal processing (iii) will be described. In the sound image processing of fig. 24, the sound image of the left and right signals of the additional sound 32 is changed within a range of 90 degrees to-90 degrees within the total time length (for example, 90 seconds) of the sound content 30. Thus, the user has the impression that the sound source moves from right to left. Therefore, when the sound image processing shown in fig. 14 is performed on the wing vibration sound generated when the bird of the sound source (5) flies, the user can have the impression that the bird flies up and moves from right to left.

The signal processing (iv) will be described. In the stereo widening processing of fig. 25, the phase difference is changed within a range of 20% to 240% with respect to the left and right signals of the additional sound 32 within the total time length (for example, 90 seconds) of the sound content 30. In fig. 25, the phase difference is 100% as a standard, and the user feels "a narrow feeling" when the phase difference is less than 100%. On the other hand, when the phase difference exceeds 100%, the user is given the impression of spatial expansion, and the user perceives "expansion feeling". Fig. 25 shows an example of processing in which the "spread feeling" and the "narrow feeling" are repeatedly obtained in 90 seconds. In fig. 25, the "spread" is gradually increased in 15 seconds in the first half and the "narrow" is gradually increased in 15 seconds in the second half with a period of 30 seconds.

The signal processing (v) will be described. Sounds radiated from the speaker units 23R and 23L shown in fig. 7 are first reflected by the side plate 5a of the car 5 to reach the ears of the user. This is the sound that reaches the user at the shortest distance. However, there is actually a sound that reaches the user's ears after being reflected multiple times by the floor 5b of the car 5, the lower surface 10b of the suspended ceiling 10, other portions of the side plates 5a of the car 5, and the like. Thus, the sound of the multiple reflections is called initial Reflection (Early Reflection). The delay time of the initial reflection is about several ms to 100 ms. The sound loses energy each time it is reflected, its amount gradually decays. The sound thus attenuated is called late reverberation (Late Reverberation). The delay time of the sound of the initial reflection and the delay time and the decay time of the sound of the late reverberation differ depending on the materials of the side plates 5a, the floor 5b, the lower surface 10b of the suspended ceiling 10, and the like of the car 5, the volume and the shape of the car 5, and the like. Therefore, the signal processing unit 44 deletes or adds the reverberation component to the left and right signals of the additive sound 32 within a range of-100 ms to +100ms as necessary. When the reverberation component is excessive, it is irritating to the user, and therefore, in this case, the reverberation component is deleted. Fig. 26 shows the original waveform of the additional sound 32 before the reverberation process is performed, and fig. 27 shows the waveform in which the reverberation component is deleted from the original waveform of the additional sound 32 after the reverberation process is performed. In addition, when the reverberation component is too small, the expansion of the sound disappears, and the sound becomes a lonely and boring sound. In this case, a reverberation component is added. When the velocity of the direct sound is 300ms, the increment amount is preferably in the range of 300ms±100 ms. By adjusting the time length of the reverberation component in accordance with the material of the car 5, the user can feel pleasant feeling by making the sound content 30 a sound that is easy to listen to.

The sound image processing of fig. 24, the stereo widening processing of fig. 25, and the reverberation processing of fig. 27 are realized by, for example, a phase control process. By adjusting the time difference Δt between the signals by the phase control process, the sound image process of fig. 24, the stereo widening process of fig. 25, and the reverberation process of fig. 27 can be realized. The method of the sound image processing in fig. 24, the stereo widening processing in fig. 25, and the reverberation processing in fig. 27 is not limited to the phase control processing, and any other conventionally known method may be used.

[ Signal processing for chord Serial tone 30B ]

The signal processing unit 44 also performs the signal processing of the above-described sound image, stereo extension, reverberation, and the like, which are described with reference to fig. 24 and 25, on the chord serial tone 30B. The method of processing these signals of the chord serial tone 30B is the same as the method of processing the signal of the additional tone 32 included in the natural environment tone 30A, and therefore, the description thereof is omitted here. In addition, regarding the effect of the above-described sound image processing on the chord serial sound 30B, the user can have the impression that the sound moves from right to left as in the case of the additional sound 32. In addition, when the above-described stereoscopic extension processing is performed on the chord serial tone 30B, the user can be given the impression of spatial extension, and the user can feel "sense of extension", as in the case of the additional tone 32. In addition, when the above-described reverberation processing is performed on the chord serial tone 30B, the user can feel "pleasant feeling" as in the case of the additional tone 32.

Alternatively, the above-described signal processing described using fig. 24 to 27 may not be performed on the chord serial tone 30B. The effect in this case will be described. In the natural environment sound 30A, signal processing such as sound image, stereo widening, and reverberation is performed on the additional sound 32. The natural BG sound 31 such as the running water sound of the river and the additional sound 32 such as the bird song sound include the natural moving feeling in the sound property. Therefore, for example, if the volume of the car 5 is small, or if the chord serial 30B is also subjected to signal processing, the sound field 27 is expanded more than necessary. In this case, the radiation sound with a disturbance in the sound image localization feeling is radiated into the car 5, and the user may feel an unpleasant sensation in the sense of hearing. Therefore, it is sufficient to appropriately determine whether or not signal processing such as sound image, stereo widening, and reverberation needs to be performed on the chord serial 30B, depending on the capacity of the car 5, or the like.

[ Control of the sound pressure level of the sound content 30 during stopping of the Car 5 ]

Next, control of the sound pressure level of the sound content 30 when the car 5 stops at the stop floor will be described. The sound field control unit 21a of the sound field control device 21 shown in fig. 2 controls the sound pressure level of the audio content 30 during reproduction. In a state where the car 5 is stopped at a stop floor and the car door 5d is opened, there is a case where a user cannot hear a voice guidance at the stop floor. Therefore, in order to cope with this problem, the sound field control unit 21a may perform fade-out processing for gradually reducing the sound pressure level of the sound content 30 before the car 5 stops at the stop floor. In this case, it is assumed that the sound field control section 21a can independently control the sound pressure level of the natural environment sound 30A and the sound pressure level of the chord serial sound 30B, respectively. In this case, the sound field control unit 21a may not decrease the sound pressure level of the chord serial sound 30B in the sound content 30 in a state where the car 5 is stopped at the stop floor and the car door 5d is opened. That is, in this case, the sound field control unit 21a may not fade out the sound pressure level of the chord serial sound 30B in the sound content 30. The reason for this will be described. As described above, the sound pressure level of the chord serial sound 30B is on average in the range of 3dB to 6dB smaller than that of the natural environment sound 30A. Therefore, even if the chord serial sound 30B is acoustically radiated, the problem that the voice guidance at the stop floor is not heard, etc. does not occur. Conversely, when the sound pressure level of the entire sound content 30 decreases and the user cannot hear the sound content 30 when the car 5 stops at the stop floor, the user may feel uneasy. Therefore, by continuing to radiate the chord serial 30B into the car 5 at the same sound pressure level, the user's sense of uneasiness can be reduced. Further, for example, when a user with an inconvenience in eyes waits for an elevator at a landing, the user can recognize the position of the car 5 by the sound of the chord serial sound 30B played from the inside of the car 5 in the stop. Therefore, the user can be guided to the position of the car 5 by the sound of the chord serial sound 30B.

[ Evaluation about Sound content 30 ]

Fig. 28 is a schematic diagram showing subjective evaluation results and physiological evaluation results of a person based on SD (SEMANTIC DIFFERENTIAL SCALE method: semantic difference scale) method. Fig. 28 shows an example of experimental results of a subject in the case where subjective amounts of the adaptability factors for the user of the elevator 1 actually moving are evaluated when the specification of the audio content 30 is changed. Fig. 4 shows the sound content 30 when the pleasantness is evaluated as the best according to the evaluation result of fig. 28.

The sound content 30 uses an evaluation result based on the SD method of evaluating impressions for sound in a plurality of stages using a plurality of adjective pairs shown in fig. 28. In the evaluation result of the factor analysis, the audio content 30 of embodiment 1 is highly evaluated.

Fig. 28 shows an example of an adjective pair used in the evaluation of the SD method. As shown in fig. 28, the subjective sound quality evaluation results and the physiological sound quality evaluation results of the SD method were each evaluated in 5 stages by using 7 adjective pairs. In particular, the 7 adjective pairs are "peaceful-restless," free-not free "," relaxed-tense "," open-closed "," pleasant-boring "," wide-narrow "," pleasant-unpleasant ". In this way, in fig. 28, pleasantness, feeling of expansion, and the like are also targets of evaluation.

Fig. 28 shows the results of experiments performed on 40 men, women, and the young as the subjects. The ratio of men to women of the tested person is 1:1, namely, 20 men and 20 women were included in the subjects. The years of the test subjects were set to 20 to 60 years. Further, the subjects did not recognize each other. Fig. 28 shows the average of the results. In the adjective pair in fig. 28, the adjective on the left is an adjective equivalent to "pleasant" or "good", and the adjective on the right is an adjective equivalent to "unpleasant" or "bad".

In fig. 28, the content of the sound radiated to the subject is as follows.

(A) : audio content 30 of embodiment 1

(B) : natural environment sound 30A of sound content 30 only

(C) : music (popular music with singing)

(D) : music (symphony without singing (generally known music))

(E) : general cage room (Silent)

Here, the audio content (a) is the audio content 30 of embodiment 1. That is, the sound content (a) includes the natural environment sound 30A and the chord serial sound 30B. The sound content (b) is only the natural environment sound 30A in the sound content 30 of embodiment 1.

Further, the sound content (c) is popular music containing singing voice. Further, the sound content (d) is an symphony song that does not contain singing. Thus, the sound contents (a) and (b) are "nonsensical sounds", and the sound contents (c) and (d) are "music" = "meaningful sounds".

Further, (e) is a state of a conventional general car room. That is, in (e), the sound content is not radiated into the car 5, and the car is in a silent state.

Fig. 28 shows subjective evaluation results and physiological evaluation results of the subjects for each of the sound contents (a) to (e) when the subjects were caused to listen to the sound contents in the car 5. As a result, as shown in fig. 28, in each adjective pair, the result of the sound content (a) is best, and the results of the sound contents (c) and (d) are all poor. From the result, it is known that the user also has a preference regarding the symphony of the sound content (d). There is also a suggestion that "no reverberation needs to be intentionally heard in the elevator car 5". In addition, popular music of the sound content (c) is greatly affected by the preference of the user, and thus, results in that reactions are classified into "pleasant" and "unpleasant".

In addition, the silence of (e) is evaluated worst among the adjective pairs. That is, it is known that the unpleasant element of the silent state in which the sound content is not radiated into the car 5 is highest for the user.

As shown in fig. 28, it is clear that the evaluation results of the popular music of the audio content (c) and the symphony of the audio content (d) are changed from "pleasant" elements to "unpleasant" elements, as compared with the audio content 30 of embodiment 1. In particular, the symphony of the sound content (d) has a large number of negative ideas such as "tension" and "stenosis" from the subject, and as a result, the impression of the car 5 is adversely affected. That is, from the factor analysis results for each audio content shown in fig. 28, it was confirmed that the audio content (a) gave better results than the other audio content. Therefore, it was confirmed that the sound content 30 of the embodiment 1, which is made of "nonsensical sound", gives the subject a feeling of ease, openness, and pleasure.

When compared with the sound contents (c) and (d), the results of the sound content (b) are all good. The sound content (B) contains only the natural environment sound 30A and does not contain the chord serial sound 30B. However, when the audio content (a) and the audio content (b) are compared, the results of the audio content (a) in embodiment 1 are all good. In particular, in the sound content (a), the level of "free", "relaxed", "pleasant" is high as compared with the sound content (b). As is clear from the result, when both the natural environment sound 30A and the chord serial sound 30B are radiated into the car 5 at the same time, the user feels more pleasant than the state of only the natural environment sound 30A. In the case of the natural environment sound 30A, in a portion where only the natural BG sound 31 is radiated without the additional sound 32, for example, only the sound of waves approaching the beach is played. In this case, the user may feel a feeling of silence in the car 5, tension or a feeling of occlusion. Therefore, in embodiment 1, the natural environment sound 30A and the chord serial sound 30B are radiated simultaneously. In this case, the natural BG tone 31 and the chord serial tone 30B are also radiated at the same time in the portion where the additional tone 32 is not present. Since the chord serial tone 30B includes the mismatch line 34, the cocktail effect can be expected as described above. Accordingly, the consciousness of the user is concentrated on the sounds generated by the natural BG sound 31 and the chord serial sound 30B, and unpleasant elements such as pressure in the closed space are reduced.

As described above, according to the evaluation result of fig. 28, it was confirmed that sounds generated in nature, which are heard by everyone, are acoustically peaceful when a confined enclosed space is closed and an unrecognized person such as an elevator is using them. Further, by adding the chord serial tone 30B including the harmony 34 to the natural environment tone 30A, the user can feel pleasant while further relaxing. On the other hand, the content of music is also based on the content, but is influenced by the likes and dislikes of the user, and the same musical composition is often listened to, so that it can be said that the feeling different from the case of natural sound is brought.

In the above description, the case where 1 or 2 pieces of sound content 30 are stored in the storage section 21c of the sound field control apparatus 21 shown in fig. 2 is mainly described. But is not limited to this case. The storage unit 21c may store a plurality of audio contents 30 for each season and each life time period. Fig. 29 is a diagram showing an example of the sound source of the additive sound 32 inserted into the natural environment sound 30A of the sound content 30 every season and every living period. As shown in fig. 29, the type of living organism used in the additional sound 32 is changed for each season and each living time zone. The natural BG sound 31 is one of the sound sources (4).

Therefore, in this case, at least (4 seasons) × (4 life time periods) =16 pieces of sound content 30 are produced. Specifically, for example, when the season is "spring" and the life time period is "morning", the sound content 30 is created such that at least 1 additional sound 32 of sparrow, bird's nest, bird's warrior, and needle cricket is added to the natural BG sound 31 of any one of the sound sources (4). For example, when the season is "autumn" and the life time period is "night", the sound content 30 of at least 1 additional sound 32 of the owl, zhong Xi, and pagoda fly is added to the natural BG sound 31 of any one of the sound sources (4). In this way, a plurality of different audio contents 30 are created in advance for each season and each life time period and stored in the storage unit 21c. The sound field control unit 21a acquires current date and time data from the timer unit 21d, and switches to the sound content 30 corresponding to the actual season and life time based on the date and time data.

In embodiment 1, a plurality of audio contents 30 may be prepared for each season and each living time zone, and the audio contents 30 may be switched in accordance with the actual season and living time zone. In this case, the user can feel the change of seasons, the change of life time, and the like in the sense of hearing without giving a feeling of uniformity to the user, and the possibility of "healing" and "ventilation" of the user is high. In addition, the user may feel happy by recognizing the switching of the audio content 30, and the car 5 mounted on the elevator 1 may become 1 fun. In this way, by switching the audio content 30, a further pressure reduction by the user can be achieved.

As described above, according to the sound system 13 of embodiment 1, a plurality of sound sources generated in nature are combined for reproduction, and at the same time, the chord serial sound 30B composed of the combination of the chord 33 and the non-chord 34 is reproduced. By radiating the sound content 30 based on the combination of the natural sound and the chord to the closed space as the object, the pressure reduction of the user in the closed space can be achieved. Thus, in embodiment 1, the chord serial tone 30B is constituted by the chord 33 and the non-chord 34. Further, the chord serial tone 30B has periodicity shown in the following (a) and (B). (a): the chord serial tone 30B is periodically reproduced by making the time length L within 2 minutes. (b): a non-consonant 34 is interposed between the consonants 33, and thus, for example, a non-consonant of 1 second is brought between the consonants of 2 seconds, and thus, has periodicity. Therefore, in the chord serial tone 30B, the tone quality change is exhibited at a certain period. Further, by combining such chord serial tone 30B and natural environment tone 30A with periodic sound quality variation, the inside of the car 5 is made a pleasant space.

In embodiment 1, the number of basic speaker boxes 20 is set to 2. By arranging at least 2 speaker boxes 20 at random in this way, the sound content 30 is radiated from a plurality of directions to the target closed space, thereby forming a three-dimensional sound field environment and obtaining a more natural sound field feeling.

As shown in fig. 10 and 11, the number of speaker units 23 mounted in 1 speaker box 20 may be 2 or more. In this case, 1 speaker is referred to as a full-range speaker, and the other speakers are referred to as low-frequency dedicated speakers or high-frequency dedicated speakers serving as auxiliary speakers for the full-range speaker. This allows the speaker box 20 alone to cope with low to high frequencies, and thus allows a broad frequency band to be radiated in a fine manner. As a result, the sound quality can be improved and the reproduction band can be enlarged, and a "high sound quality system" which can cover a wide frequency band can be easily obtained.

However, the number of speaker boxes 20 and speaker units 23 may be 1. In this case, the sound field control unit 21a also radiates the sound content 30, which is a combination of the natural environment sound 30A and the chord serial sound 30B, into the car 5. This brings about "healing" and "ventilation" of the user in the closed space, and further pressure reduction of the user can be achieved.

In embodiment 1, by the above-described radiation of the sound signal, a sound field space is created in a closed space, for example, in the car 5 of the elevator 1 where there are many opportunities for people to ride together, at a position on the head of a user or above the chest of the user. This allows the user to feel a narrow space as a wide space in the sense of hearing while riding on the car 5. As a result, it is possible to reduce stress caused by "unsmooth" and "unpleasant feeling" when riding with an unknown person in a narrow environment.

In embodiment 1, a sound signal based on the sound content 30 formed by combining the natural environment sound 30A and the chord serial sound 30B is radiated from the speaker system 22. In a closed space such as the car 5 of the elevator 1 where there are many opportunities for people not to know to ride together, such a radiation sound using the sound of the natural world can make the user feel a narrow space as a wide space in the sense of hearing, and can reduce the pressure. Further, since the natural sound is "nonsensical sound", the preference of the user is less likely to be classified, regardless of the type of preference of the user. Further, in the case where the sound content 30 is "nonsensical sound", the user does not particularly want to listen to the sound content 30 from the beginning or listen to the sound content 30 to the end. Therefore, even if the user gets on the car 5 or gets off the car 5 during reproduction of the audio content 30, no particular stress is applied to the user.

Further, as shown in fig. 29, the audio content 30 may be prepared for each season and each life time, and the audio content 30 may be switched in accordance with the actual season and life time. In this case, the user can feel season changes, life time period changes, and the like without giving a feeling of uniformity to the user, and the possibility of "healing" and "ventilation" of the user is high. As a result, a further pressure reduction by the user is achieved.

In embodiment 1 described above, the interior space of the car 5 of the elevator 1 is exemplified as the closed space, but the closed space may be a waiting room of a hospital or a pharmacy. In the case where the closed space is a waiting room of a hospital or pharmacy, the housing 25 of each speaker box 20 is disposed on the upper surface of a ceiling plate of the waiting room. That is, the case 25 of each speaker box 20 is provided in the ceiling space above the ceiling plate. Further, considering the case where the user sits on a chair, the height of the generated sound field 27 is set to be in the range of 1.2m to 1.4m, for example.

The enclosed space may be an in-vehicle space of an automobile or a train. Automobiles include passenger cars and buses. When the closed space is an interior space of a passenger car such as a taxi, the case 25 of each speaker box 20 is disposed in a ceiling of the interior space or in an instrument panel of a driver's seat. In this case, the height of the generated sound field 27 is set to, for example, a range of 1.2m to 1.4m, considering that the user sits on the seat of the passenger car. On the other hand, when the enclosed space is an in-vehicle space of an electric car or a bus, the case 25 of each speaker box 20 is disposed in a ceiling of the in-vehicle space. In this case, the height of the generated sound field 27 may be set to, for example, 1.6m to 1.8m in combination with a user standing in the vehicle, but may be set to, for example, 1.2m to 1.4m in combination with a user sitting in the seat.

Description of the reference numerals

1: An elevator; 2: a hoistway; 3: a traction machine; 3a: a rope pulley; 4: a main rope; 5: a car; 5a: a side plate; 5b: a floor; 5c: a ceiling panel; 5d: a car door; 5e: a lighting device; 5ea: an irradiation surface; 5f: a car operating panel; 5g: an emergency speaker; 5h: an interphone device; 6: a counterweight; 7: an elevator control panel; 8: a control cable; 9: a car control device; 9a: an input unit; 9b: a control unit; 9c: an output unit; 9d: a storage unit; 10: suspending the ceiling; 10a: a side surface; 10b: a lower surface; 11: a void; 13: sound systems (sound systems) for enclosed spaces; 20: a speaker box; 21: a sound field control device; 21a: a sound field control unit; 21b: an output unit; 21c: a storage unit; 21d: a timer unit; 22: a speaker system; 23: a speaker unit; 23-1: a speaker unit; 23-2: a speaker unit; 23L: a speaker unit; 23L-1: a speaker unit; 23L-2: a speaker unit; 23R: a speaker unit; 23R-1: a speaker unit; 23R-2: a speaker unit; 23a: a radiation surface; 25: a housing; 25a: a front face; 27: a sound field; 27a: a lower limit; 30: sound content; 30A: natural environmental sounds; 30B: chord serial tone; 30a: a joining portion; 31: natural BG sounds; 32: an additional sound; 33: synergism; 34: incoordination; 35: a time interval; 36: a prelude section; 37: a middle playing part; 38: a back playing part; 40: a sound content generating device; 41: an input unit; 41a: a1 st input unit; 41b: a2 nd input unit; 42: a natural environment sound generation unit; 43: a chord serial tone generating section; 44: a signal processing section; 45: a mixing processing unit; 46: an output unit; 47: a storage unit; 50: thick lines; 51: a thin wire; 60: a sound material database.

Claims

1. A sound system for an enclosed space, the sound system comprising:

a speaker system disposed in the closed space and mounted with a speaker unit;

A storage unit that stores audio content; and

A sound field control section that radiates a sound signal based on the sound content from the speaker system to the enclosed space,

The sound content includes:

a natural environmental sound representing environmental sounds generated in nature; and

Chord serial tones composed of combinations of chords including chord and non-chord.

2. The sound system for an enclosed space according to claim 1, wherein,

The sound content is constituted by adding the chord serial sound to the natural environment sound,

The natural environment sound and the chord serial sound are radiated from the speaker system at the same time.

3. The sound system for an enclosed space according to claim 1 or 2, wherein,

The chord serial tone is composed of the harmony tone and the non-harmony tone alternately arranged.

4. The sound system for an enclosed space according to claim 3, wherein,

The chord at the beginning of the chord serial tone is one of the harmony tone and the incoordination tone,

The chord at the end of the chord serial tone is the other of the harmony tone and the incoordination tone.

5. The sound system for an enclosed space according to any one of claim 1 to 4, wherein,

The duration of the harmony is the same as or longer than the duration of the non-harmony.

6. The sound system for an enclosed space according to any one of claims 1 to 5, wherein,

The chord serial tone is composed of the chord within 1 octave and the non-chord within 1 octave.

7. The sound system for an enclosed space according to any one of claims 1 to 6, wherein,

The sound pressure level of the natural environment sound is greater than that of the chord serial sound.

8. The sound system for an enclosed space according to claim 7, wherein,

The difference between the sound pressure level of the natural environment sound and the sound pressure level of the chord serial sound is in a range of 3dB or more and 6dB or less.

9. The sound system for an enclosed space according to any one of claim 1 to 8, wherein,

The natural environment sound includes:

a natural background sound representing a sound generated according to a state of the natural environment; and

An additional sound added to the natural background sound,

The natural environment sound is constructed by adding the additional sound to the natural background sound, and combining the natural background sound and the additional sound.

10. The sound system for an enclosed space according to claim 9, wherein,

The natural background sound includes at least one of a sound of a tree swinging with a wind, a sound of water flowing in a river or ocean, a loud sound, a moving sound of an artificial object, and a sound of a person.

11. The sound system for an enclosed space according to claim 9 or 10, wherein,

The additional sound is a sound generated due to the behavior of the living being in nature,

The additional sound includes at least one of 1 or more bird sounds, 1 or more wing sounds when the bird flies, 1 or more insect sounds, and 1 or more animal sounds.

12. The sound system for an enclosed space according to any one of claims 9 to 11, wherein,

The sound pressure level of the additional sound is greater than that of the natural background sound.

13. The sound system for an enclosed space according to claim 12, wherein,

The difference between the sound pressure level of the additional sound and the sound pressure level of the natural background sound is 10dB or more.

14. The sound system for an enclosed space according to any one of claims 1 to 13, wherein,

The overall length of time of the sound content is 2 minutes or less,

The sound field control section repeatedly and continuously radiates the sound signal based on the sound content from the speaker system.

15. The sound system for an enclosed space according to claim 14, wherein,

The sound content is structured such that,

A fade-in process is performed on an opening portion of the sound content to gradually increase a sound pressure level of the sound content,

A fade-out process is performed on an end portion of the sound content to gradually decrease a sound pressure level of the sound content,

In the case where the sound signals based on the sound contents are repeatedly and continuously radiated from the speaker system, the sound pressure level of the joined portion of the sound contents to each other is minimized.

16. The sound system for an enclosed space according to any one of claims 1 to 15, wherein,

The main band of the frequency of the chord serial tone is set to be 100Hz or more and 800Hz or less.

17. The sound system for an enclosed space according to claim 9 or any one of claims 10 to 16 when dependent on claim 9, wherein,

The frequency band of the additional sound is set to be 800Hz or more and 15kHz or less.

18. The sound system for an enclosed space according to any one of claims 1 to 17, wherein,

The closed space is the inner space of the car of the elevator,

Each speaker unit is disposed in at least one of the ceiling plate of the car, the side plate of the car, and the floor of the car, and the ceiling plate of the car is fixed to the ceiling plate of the elevator.