JPH06311600A - Image displacement control information generating system and acoustic system - Google Patents

Abstract

PURPOSE:To form a sound field where a sound source can be moved by drawing a desired locus by forming an image by freely switching the phase and level of acoustic signals sent from plural electro-acoustic transducer means arranged in a hall. CONSTITUTION:A personal computer 40 displays the coordinates of speakers 391-396 in a hall on a CRT, and stores the contents of the coordinates. Also, the personal computer 40 converts the phase and level set in advance both to attenuation quantity by variable attenuators 361-366, and to delaying time generated by difference of readout addresses of RAMs 341-346, and holds a conversion result as a table corresponding to the coordinates and the frequency component of the sound source. The personal computer 40 outputs default values for a signal switching period, sending time, and the frequency component from a CD player 31 to a processor 42 as set values. Thereby, the phase and level of an analog audio signal supplied to the speakers 391-396 can be switched, and the sound field where the sound source is moved by drawing the desired locus can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic system for forming a sound field in which a sound source is displaced in time series at an event site of a department store or an exhibition.

[0002]

2. Description of the Related Art In department stores, halls, stadiums and other event venues, a broadcasting system has been introduced in order to simultaneously transmit information by voice to a large number of people dispersed in a large venue. For such a broadcasting system, in order to reliably transmit information by voice, it is possible to amplify the audio signal or perform electro-acoustic conversion in accordance with the acoustic characteristics of the ear of the venue or the audience where the broadcasting is performed. Various technologies have been proposed.

In addition, at present, in order to reproduce the original sound field as faithfully as possible not only in a movie theater or a theater but also in a general household, the sense of localization and the original sound for identifying the direction in which the performer is playing. Stereo audio systems, which provide a sense of spaciousness that distinguishes the reverberation and width of the acoustic space of a field, have become widespread.

[0004]

By the way, such a conventional broadcasting system or stereo audio system is configured for the purpose of faithfully converting the recorded audio information into sound, and the above-mentioned sense of localization and expansiveness are eliminated. , It was not reproduced unless it was included in advance when the voice information was recorded.

However, in recent years, at a specific venue or another event venue provided in a department store, a sound source that emits a sound (for example, a song of a small bird flying in the space of a forest bath rest area) suitable for the content of the event to be held. There is a demand for acoustically simulating a desired space by obtaining an acoustic effect that is equivalent to a case of moving along a predetermined trajectory. Further, the sound emitted from such a sound source is not only obtained by actually recording from the natural world, but also artificially generated using an electronic musical instrument or the like according to the diversification of the held event. Many things are being used.

It is an object of the present invention to provide an acoustic system that acoustically simulates the presence of a sound source moving in an arbitrary trajectory in a venue.

[0007]

FIG. 1 is a block diagram showing the principle of the invention described in claim 1. In FIG. The present invention stores the phases and levels of acoustic signals emitted in parallel from a plurality of positions installed in a venue in association with each position of a sound image formed in the venue as a vector sum of these acoustic signals. For the storage unit 11 and the position along the time series on the trajectory where the sound image should be displaced and drawn in the venue, the phase and level stored in the storage unit 11 corresponding to the position are read out, and these phases and levels are read. Control information generating means 13 for generating sound image displacement control information composed of a set of

FIG. 2 shows the principle block of the invention according to claim 2.
FIG. The present invention provides a sound image displacement control according to claim 1.
The sound image displacement control information generated by the control information generation method.
The storage means 21 to hold and the sound stored in the storage means 21
It is placed individually in the venue corresponding to the image displacement control information and
The same audio signal is captured and the audio signal is
Electric-acoustic conversion means 23 for transmitting electric-acoustic conversion after transmission
₁~ 23_NAnd the sound image displacement control stored in the storage means 21.
The information is read out in chronological order and used as the sound image displacement control information.
The included phase and level are converted into electric-acoustic conversion means 23.₁
~ 23_NSound image displacement control means 25 set via
It is characterized by what you got.

[0009]

In the sound image displacement control information generating method according to the first aspect, the storage means 11 forms the sound image in advance in correspondence with each position which can be located on the trajectory drawn by the sound image displaced in the hall. The individual phases and levels of the acoustic signals to be emitted in parallel from a plurality of positions installed in the venue for storing are stored. The control information generation unit 13 reads out the phase and level stored in the storage unit 11 corresponding to each position along the time series on the above-described locus and generates the sound image displacement control information.

Therefore, with respect to a plurality of fixed sound sources set in advance in the hall, the phases and levels of the acoustic signals to be transmitted in order to simulate the sound source that freely moves in the hall as a sound image are given in chronological order. Sound image displacement control information is generated.

In the acoustic system according to the second aspect, the sound image displacement control means 25 sequentially reads out the sound image displacement control information stored in the storage means 21 in time series, and the phase and level included in the sound image displacement control information. Are set in the electro-acoustic conversion means 23 ₁ to 23 _N.

In this way, the electro-acoustic conversion means 23 ₁
Since ~ 23 _N converts the same audio-frequency signal into acoustic signals of the phase and level set in this way and sends them out in parallel to the venue, the vector of these acoustic signals is placed in the venue. A sound image that displaces in accordance with the sum is formed, and a sound source that moves along an arbitrary trajectory according to the content of the sound image displacement control information described above is acoustically simulated in the venue.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 is a diagram showing an embodiment corresponding to the invention described in claims 1 and 2.

In the figure, the output of the CD player 31 is connected to the input of an AD converter (ADC) 33 via a preamplifier 32, and the output thereof is a dual port RAM (RAM).
(Hereinafter, simply referred to as “RAM”.) 34 _{1 to} 34 ₆ are connected to the data inputs. RAM 34 ₁ to 34C data output ₆ is connected individually to D-A converter (DAC) input 35 _{1-35 6,} these outputs variable attenuator (ATT) 36
_{1-36 6,} is connected to the equalizing amplifier 37 _{1-37 6} and the power amplifier 38 ₁ to 38 ₆ speaker 39 ₁ arranged in the region for forming a sound field in the event hall through to 39 _6. Communication connector provided in the personal computer 40 is connected to the communication connector of the processor 42 via the communication cable 41, DMA bus of the processing unit 42 writes the address input of the RAM 34 ₁ to 34C ₆ via the address control unit 43 Connected to. The input / output bus of the processing device 42 includes a phase shift control unit 44 and an attenuation amount control unit 45.
, And the output of the phase shift control unit 44 is connected to the read address input of the RAMs 34 _{1 to} 34 ₆ . The output of the attenuation amount control unit 45 is connected to the control inputs of the variable attenuators 36 _{1 to} 36 ₆ .

Regarding the correspondence relationship between this embodiment and the block diagrams shown in FIGS. 1 and 2, the personal computer 40 and the communication cable 41 correspond to the storage means 11 and the control information generating means 13, the processing device 42, the address. The control unit 43, the phase shift control unit 44 and the attenuation amount control unit 45 correspond to the storage means 21, and include the preamplifier 32, the equalization amplifiers 37 _{1 to} 37 ₆ , the power amplifiers 38 _{1 to} 38 ₆ and the speakers 39 _{1 to} 39. ₆ is an electro-acoustic conversion means 23 ₁ to 2
Corresponding to 3 _N , address control unit 43, phase shift control unit 44, attenuation control unit 45, A / D converter 3
3, RAM 34 _{1 to} 34 ₆ , D / A converters 35 _{1 to} 35
₆ and the variable attenuators 36 _{1 to} 36 ₆ correspond to the sound image displacement control means 25.

The operation of this embodiment will be described below. Speaker 39 _{1-39 6} in event venues sound system according to this embodiment is installed, is arranged a sound field sound source is moved along a locus in advance a certain position in order to simulate acoustically.

The personal computer 40 displays the sketch of such an event hall on CRT, the coordinates of the speaker 39 _{1-39 6} at the venue to the operator, as the above-described trajectory, each along its trajectory The apparent movement speed in the section is plotted on the display screen and input, and the contents are stored.

Further, the personal computer 40 simulates the movement of the sound source along such a locus so that the speakers 39 ₁ to 39 _1- .
And switching period of the audio signal to be transmitted from 39 _6, and times to be sent to the acoustic signal, the frequency component of the audio signal outputted from the CD player 31, a set value the default value, the operator These set values are appropriately updated based on the operation to be performed.

Further, the personal computer 40, the above-mentioned coordinates, trajectory, when in parallel according to the movement speed and the switching period of the apparent from the speaker 39 _{1-39 6} sequence (t = 1, 2,
..), the attenuation amounts L _{1t to} L _{6t of} the variable attenuators 36 _{1 to} 36 ₆ for setting the levels.
And the delay times (differences) D _{1t to} D _6t determined by the read addresses of the RAMs 34 _{1 to} 34 ₆ are calculated by the following procedure. The value of the above-described switching period is set to be equal to or less than the upper limit value (≈50 ms) at which it is possible to avoid that the acoustic signals sent by switching are heard separately.

[0020] In this embodiment, venue speaker 39 _{1-39 6} is arranged is treated as a set of a plurality of grating formed by dividing logically a lattice shape at a predetermined interval. Hereinafter, the coordinates indicating the position of such a lattice are referred to as “lattice coordinates”, and for all positions of the plurality of lattices described above, in order to match the localization point of the sound source for each frequency component of the sound source, level and the phase of the acoustic signal to be transmitted from the speaker 39 _{1-39 6} based on the combination of acoustic phenomena as shown in ~ of are actually measured. When the acoustic signals transmitted from the two speakers at substantially the same time mainly include a large number of frequency components of a predetermined value F _S (= 4000 Hz) or more, the one of the speakers having a higher level (sound pressure) of the acoustic signals transmitted is Direction, on the contrary, in the case of a frequency component having a frequency lower than F _S , a phenomenon in which a pseudo sound source (sound image) is formed that is displaced in the direction of the speaker side that outputs the acoustic signal with the phase advance, When the same acoustic signal is transmitted from the speakers with a level difference of a predetermined value L _S1 (≈10 dB) or less, the direction of the pseudo sound source recognized by the listener who is located at the apex of an equilateral triangle having the intervals between these speakers as one side. Direction orientation of a stereo sound image that changes substantially linearly with respect to the level difference, and when the same acoustic signal is given to both ears of the listener, the level difference between both acoustic signals is set to a predetermined value L _S2 (≈11 dB) or more. When set Large acoustic signal is recognized that there is a sound source in the direction of the ear given, and a predetermined value a delay time difference between the audio signal D _S Bell (≒ 0.65 ms)
When the above settings are made, the sound image phenomenon in which the sound source is recognized to be in the ear direction of the earliest arrival, and the level difference between the acoustic signals transmitted from the two speakers in the sound field in which the direction localization of the stereo sound image described above is obtained is predetermined. When the value exceeds (= 20 to 25 dB), the direction of the pseudo sound source is localized to the speaker side with the higher transmission level, and the same acoustic signal is transmitted from the two speakers with a predetermined delay time difference (about 1 to 30 ms). In this state, the preceding sound effect in which the listener, who is located at a point equidistant from these speakers, perceives only one speaker as a sound source, which sends out an acoustic signal without delay time, A certain delay time difference (≈50ms)
In a state where the sound source exceeds the above, the listener can separate and hear the acoustic signal transmitted from each speaker. The sound separation effect Note that in the following, the phenomenon in which the pseudo sound source is localized by any combination of Is broadly referred to as a sound image phenomenon, and the above-mentioned (1) to (7) are applied when such a sound image phenomenon cannot be used due to the above-mentioned predetermined values F _S , L _S1 , L _S2 , D _{S, and} other physical restrictions. Shall be done.

The personal computer 40 uses the variable attenuators 36 ₁ to 36 3 to respectively set the level and the phase set in this way in advance.
6 and attenuation L _1t ~L _6t to be set to _6, RAM 34 ₁ ~
34 converts ₆ in the difference delay time D _1t to D _6t to be implemented by the read address, and holds the result of the conversion as a table corresponding to the frequency components of the sound source as described above with grid coordinates.

Further, the personal computer 40 integrates the moving speed of the pseudo sound source in each section on the time series for each switching cycle described above to obtain the position taken by the pseudo sound source in the order of the time series.
The coordinates of these positions are individually approximated using the grid coordinates that minimize the error.

Further, the personal computer 40 refers to the above-mentioned table on the basis of the individual grid coordinates obtained in the order of time series by such an approximation and the frequency component of the audio signal outputted by the CD player 31, and refers to the table. The parameters shown in FIG. 4 are generated collectively by the delay times D _{1t to} D _6t and the attenuation amounts L _{1t to} L _6t obtained as a result. The personal computer 40 transmits the above-mentioned parameters, the switching cycle of these parameters, and the time zone in which the acoustic signal should be transmitted to the opposing processing device 42 via the communication cable 41 based on a predetermined communication procedure.

When the processing device 42 holds the information received from the personal computer 40 according to such a communication procedure, whether the time given by the built-in calendar clock is included in the transmission time zone of the acoustic signal included in the information. Monitor whether or not. When the processor 42 recognizes that the sending time has arrived by such monitoring, it activates the address control unit 43, and among the information held as described above, the delay times D _{1t to} D _6t included in the parameters. (T = 1,2, ...) And the switching cycle of the parameters are given to the phase shift control unit 44, and the attenuation amounts L _{1t to} L _6t (t = 1,2,
...) and the parameter switching period are given to the attenuation amount control unit 45.

The address control unit 43, when activated in this way, generates the same write address that is updated cyclically and supplies it to the RAMs 34 ₁ to 34 ₆ . The phase shift control unit 44 receives the given delay time D _1t.
~ D _6t (t = 1,2, ...) Is fetched and RAMs 34 _{1 to} 34 ₆
As a correction value of the read address of the above, equivalent values a _{1t to} a _6t (t = 1, 2, ...) Of these delay times are obtained and stored, and a length equal to the switching cycle of the parameters given together with these delay times is obtained. Start Sano's timer.

The attenuation amount control unit 45 takes in the given attenuation amounts L _{1t to} L _6t (t = 1, 2, ...) And sets them in the variable attenuators 36 _{1 to} 36 ₆ to obtain these attenuation amounts. The control values c _{1t to} c _6t (t = 1, 2, ...) Are calculated and stored, and a timer having a length equal to the switching cycle of the parameters given together with these attenuation amounts is started.

In this way, the address control unit 4
3, phase shift control unit 44 and attenuation amount control unit 4
In a state where 5 is started, RAM 34 ₁ to 34C ₆ is a storage area corresponding to the write address is sequentially supplied from the address control unit 43, the analog voice signal provided via the pre-amplifier 32 from the CD player 31 The digital signals generated by the A / D converter 33 are sequentially stored.

The phase shift control unit 44 provides the read addresses, which are cyclically updated in synchronism with the update cycle of the write address output from the address control unit 43, with corresponding values a _{1t to} a _{6t for} each cycle given by the timer. (T
= 1,2, ...) is added to perform correction, and RAMs 34 _{1 to} 34
_It is given as a read address of ₆ . Therefore, RA
Digital signals are read from the outputs of M34 _{1 to} 34 ₆ at different timings according to the read addresses thus corrected, and the D-A converters 35 _{1 to} 35 ₆ respond to such digital signals. It outputs analog audio signals whose phases are periodically different.

The attenuation amount control unit 45 switches and supplies the control values c _{1t to} c _6t (t = 1, 2, ...) To the variable attenuators 36 _{1 to} 36 ₆ in each cycle given by the activated timer. Therefore, the outputs of the variable attenuators 36 _{1 to} 36 ₆ are D-
The analog voice signals obtained at the outputs of the A converters 35 _{1 to} 35 ₆ are individually obtained at periodically different levels, and the speakers are output via the equalization amplifiers 37 _{1 to} 37 ₆ and the power amplifiers 38 _{1 to} 38 _6. 39 is supplied to _{1-39 6.}

As described above, according to this embodiment, the speaker 3
9 _1-39 analog audio signal applied to ₆ phase and level is changed in correspondence with any combination of the acoustic phenomenon of ~ described above, the speaker 39 _{1-39 6} based on such sound effects are placed A sound field in which the sound source moves in a desired trajectory is formed in the venue.

In this embodiment, the venue is logically divided into a grid shape, and the points on the trajectory drawn by the pseudo sound source when moving are approximated by the grid coordinates, and various sound phenomena are used to form the pseudo sound source. In order to do so, the phase and level of the audio signal to be supplied to each speaker are switched by referring to the table that gives the measured values of the phase and level of the acoustic signal to be sent from each speaker. The invention is not limited to such a method. For example, the two speakers closest to the position of the pseudo sound source are selected, and the difference in the linear distance between these speakers and the position of the pseudo sound source, the pseudo sound source Select the best available acoustic phenomenon within the constraints of the frequency content of the acoustic signal emitted by the speaker, the relative position of the listener to these loudspeakers, the acoustic characteristics of the venue or the ear of the listener, and other constraints, If the phase difference and level difference required to realize the selected acoustic phenomenon can be calculated in real time by arithmetic operation or other predetermined algorithm, the phase shift obtained by actual measurement without lattice coordinate approximation is performed. It can be realized without using quantity or level difference.

Further, in the present embodiment, the two nearest speakers are sequentially selected along the movement locus of the pseudo sound source, and the acoustic signal is transmitted only from these speakers. However, the present invention has such a configuration. However, the sound source is three-dimensionally generated by, for example, individually transmitting acoustic signals from the above-mentioned speakers located on the locus or transmitting acoustic signals from three or more speakers at predetermined phases and levels. The sound field moving to can be simulated.

Further, in the present embodiment, no treatment is made on the error in the position of the pseudo sound source caused by the reflected sound from the wall, ceiling, floor surface and the like installed in the venue.
In the present invention, a material having good absorption characteristics is used for walls, ceilings,
It is not necessary to configure the floor surface or the like, and for example, an image source supposed to be a sound source that emits a reflected sound to the opposite side through these surfaces can be actively used as a sound source for obtaining a desired acoustic phenomenon, or directly. Actively use it as an increase in the sense of distance and spread obtained by hearing the synthesized wave with the sound,
Of the included frequency components when the reflected sound becomes noise,
It may be removed through the main component filter of the offensive sound.

Further, in the present embodiment, the sound field in which the sound source moves is simulated by combining various acoustic phenomena. Regarding the sensation and psychological characteristics (auditory physiology) that humans feel according to such acoustic phenomena, It is sufficient to adopt an acoustic phenomenon in which an effect is obtained with a desired accuracy in consideration of fluctuations due to age, concentration, and other physiological or psychological states. If necessary, for example, a time delay device or a reverberation device. You may use together.

Furthermore, in the present embodiment, the acoustic phenomenon described above is used by assuming that the frequency components of the acoustic signal transmitted from the sound source are concentrated and distributed in a specific frequency band, but in the present invention, The present invention is not limited to such an acoustic signal, and in particular, regarding the control of the delay (phase shift) amount, if the distribution of frequency components has a spread, it may be divided into a plurality of bands and controlled individually.

Further, in this embodiment, the speakers 39 _{1 to} 3 are used.
9 ₆ electro - although not described at all for transducing characteristics and directivity characteristics, the present invention is effectively available various acoustic phenomena described above in accordance with the shape of the hall, other constellation points of the speakers Then, a speaker having any characteristics may be used.

Further, in this embodiment, the RAMs 34 _{1 to} 3 are
4 is the phase of the acoustic signal transmitted from the speaker 39 _{1-39 6} by shifting the ₆ read address is variably controlled, the present invention is not limited to such a method, what type A phase shift circuit may be used.

Further, in the present embodiment, the CD player 31 performs some start control (including selection of a signal to be transmitted as a sound source) in the process of repeatedly transmitting a predetermined signal. However, the present invention is not limited to such a configuration, and for example, the processing device 42 may perform start / stop control and the like in synchronization with control of the address control unit 43 and the like.

[0039]

As described above, according to the present invention, a sound image is formed by freely switching the phases and levels of the acoustic signals transmitted from the plurality of electro-acoustic converting means arranged in the venue, and the sound source is The sound field moving in a desired trajectory is simulated.

Therefore, at the event venue to which the present invention is applied, it is possible to give the visitor a sense of presence of a sound source that dynamically moves by producing a sound that matches the content of the event to be held, and the prerecorded audio information is recorded. It is possible to obtain an effective acoustic effect that cannot be realized by the conventional broadcasting system or stereo audio system configured for faithfully converting the sound.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the invention according to claim 1.

FIG. 2 is a principle block diagram of the invention described in claim 2.

FIG. 3 is a diagram showing an embodiment corresponding to the invention described in claims 1 and 2.

FIG. 4 is a diagram showing the contents of parameters calculated by a personal computer.

[Explanation of symbols]

 11 storage means 13 control information generation means 21 storage means 23 electric-acoustic conversion means 25 sound image displacement control means 31 CD player 32 preamplifier 33 AD converter (ADC) 34 dual-port RAM (RAM) 35 DA conversion Device (DAC) 36 Variable attenuator 37 Equalizing amplifier 38 Power amplifier 39 Speaker 40 Personal computer 41 Communication cable 42 Processor 43 Address control unit 44 Phase shift control unit 45 Attenuation control unit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuo Yoshimura 1920, Kamimizo, Sagamihara-shi, Kanagawa Takeshiba Electric Co., Ltd.

Claims (2)

[Claims] 1. The phase and level of acoustic signals emitted in parallel from a plurality of positions installed in a venue are associated with respective positions of a sound image formed in the venue as a vector sum of these acoustic signals. Storage means for storing (11)
And with respect to a position along the time series on the trajectory where the sound image should be displaced and drawn in the venue, the phase and level stored in the storage means (11) corresponding to the position are read out,
A sound image displacement control information generation method comprising: a control information generation means (13) for generating sound image displacement control information composed of a set of these phases and levels. 2. Storage means (21) for holding the sound image displacement control information generated by the sound image displacement control information generation method according to claim 1, and sound image displacement control information stored in the storage means (21). captures the same audio signal is arranged separately in the corresponding venue, its audio signal in parallel electrical - electrical sent by transducing - acoustic conversion means (23 ₁ ~23 _N), the storage means (21) read in the order of time-series sound image displacement control information stored in its said phase and level electrical included in the sound image displacement control information - acoustic transducer means (23 ₁ -
23 _N ) and a sound image displacement control means (25) for setting the sound system.