JP2015125253A - Siren sound output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a siren sound output device capable of efficiently generating a siren sound easy to hear for a person inside a vehicle and a pedestrian.SOLUTION: There is provided a siren output device which outputs a siren sound for an emergency vehicle from a speaker. The siren sound output device includes a sound generation part. The sound generation part generates a first synthesized siren sound which adds a first additional siren sound to a basic siren sound. When the frequency of the basic siren sound is taken as fand the first additional siren sound is taken as f, formulas f<f<2fand f+20 Hz≤fare established.

Description

  The present invention relates to a siren sound output device for outputting siren sounds for emergency vehicles such as fire engines, ambulances, and police cars from a speaker.

  Usually, emergency vehicles such as fire engines, ambulances, and police cars are equipped with siren sound output devices for outputting siren sounds for alerting the surroundings through a speaker. This type of siren sound is subject to certain restrictions by laws and regulations. For example, if it is a siren sound of a fire engine, it is defined as a sound that transitions between 320 Hz and 780 Hz, which we usually hear. Moreover, if it is a siren sound of an ambulance, it is determined as a sound which alternately repeats a sound of 960 Hz (so-called beep sound) and a sound of 770 Hz (so-called po sound).

  However, siren sounds (hereinafter referred to as limit sounds) having the above frequencies determined by laws and regulations are not always optimal under any environment. In Patent Document 1, a sound with a frequency different from that of the octave (n is an integer) is superimposed on the limit sound so as not to inconvenience residents in a quiet residential area or an area around a fire station where emergency vehicles are frequently dispatched. Technology has been proposed. As a result, while complying with restrictions such as laws and regulations, the limit sound and the sound superimposed on it form a comfortable chord, reducing the discomfort of the residents.

JP 2004-69960 A

  By the way, in recent years, the sound insulation performance of the window glass of an automobile has been further improved. Under such circumstances, there is a fear that a driver may have difficulty in hearing siren sounds. In particular, the higher the frequency, the greater the amount of attenuation and the more difficult it is to transmit through the window glass. Therefore, in order to deliver the siren sound more reliably to the driver in the vehicle, it is desirable to blow a sound in a lower frequency range. On the other hand, as shown by an equal loudness curve (a curve in which points having the same perceived volume in the sound pressure level-frequency space are connected as contour lines), the human perceived volume is a frequency around the limit sound. In the band, sounds with higher frequencies tend to be heard louder. Therefore, it can be said that it is desirable to sound a higher frequency range if considering the alerting power and warning performance for pedestrians. From the above, in order to make the siren sound easily reachable to drivers and pedestrians in the vehicle, it is desirable to generate both high-frequency and low-frequency sounds rather than the limit sound. Patent Document 1 discloses that a sound one octave and two octaves higher than the limit sound is added to the limit sound, but such a method has a warning power and warning property. From the point of view, it is not enough.

  An object of this invention is to provide the siren sound output device which can produce | generate efficiently the siren sound which is easy to hear for the person and the pedestrian in a vehicle.

A siren sound output device according to a first aspect of the present invention is a siren sound output device for outputting a siren sound for an emergency vehicle from a speaker, and includes a sound generation unit. The sound generation unit generates a first synthesized siren sound obtained by adding a first additional siren sound to a basic siren sound. When the frequency of the basic siren sound is f _a and the frequency of the first additional siren sound is f _b , f _a <f _b <2f _a and f _a +20 Hz ≦ f _b .

Here, _a first synthesized siren sound is generated by adding the first additional siren sound of the frequency f _b to the basic siren sound of the frequency fa. Frequency f _b satisfy the relationship of f _a <f _b <2f _a and f _a + 20Hz ≦ f _b. That is, here, since f _a <f _b , the first additional siren sound that is higher than the basic siren sound can be blown. Accordingly, the volume of human perception can be increased, and the warning performance of siren sounds can be further enhanced. Further, when such a sound is output from the speaker, harmonics of the fundamental siren _{(2f a, 3f a, 4f} a, sound frequencies.) And harmonics of the first additional siren (2f _b, 3f _b , 4f _b ,...) are also generated. Therefore, here, a high-frequency sound (usually referred to as 2 kHz to 5 kHz) that can be easily heard by the human ear is efficiently generated by the harmonic component of the first additional siren sound in the high-frequency range than the basic siren sound. .

In addition, when a plurality of sounds having different frequencies are output from the speaker, their difference sounds are generated at the same time. Here are the f _b <2f _a and f _a + 20Hz ≦ f _b, the frequency f _c of the difference tone to the base siren sound and the first additional siren sound, satisfies the relationship 20Hz ≦ f _c <f _a. Note that the human audible region is generally said to be 20 Hz to 20 kHz. Therefore, here, it is possible to generate a sound that can be heard by a person's ear and that is lower in frequency range than the basic siren sound, that is, more easily transmitted through the window glass of the automobile than the basic siren sound.

  As described above, here, by outputting a sound obtained by synthesizing the first additional siren sound as described above to the basic siren sound, it is possible to generate both a high-frequency sound and a low-frequency sound than the basic siren sound. . Accordingly, it is possible to efficiently generate a siren sound that can be easily heard by people in the vehicle and pedestrians with a small amount of additional sound.

Siren sound output device according to a second aspect of the present invention, there is provided a siren sound output device of the first aspect, wherein the frequency f _b is generating the basic siren sound and the first additional siren sound and the consonance It is set not to.

  Here, the basic siren sound and the first additional siren sound are set so as not to generate a consonant sound. Therefore, it is possible to maintain the siren sound warning.

The siren sound output device according to a third aspect of the present invention is the siren sound output device according to the first aspect or the second aspect, wherein the first additional siren sound has a section where 1000 Hz ≦ f _b .

Here, since 1000 Hz ≦ f _b , a sound in a high frequency range (usually referred to as 2 kHz to 5 kHz) that can be easily heard by human ears is more efficiently generated by the harmonic component of the first additional siren sound having the frequency f _b . Can be generated.

A siren sound output device according to a fourth aspect of the present invention is the siren sound output device according to any of the first to third aspects, wherein the first additional siren sound satisfies f _a +200 Hz ≦ f _b. It has a section.

Here, since the frequency f _c of the difference between the basic siren sound and the first additional siren sound is f _c ≧ 200 Hz, a sound in a low frequency range (usually said to be 200 Hz or more) that can be easily heard by the human ear is obtained. It can be generated more efficiently.

A siren sound output device according to a fifth aspect of the present invention is the siren sound output device according to any of the first to fourth aspects, wherein the first additional siren sound satisfies f _b ≦ f _a +600 Hz. It has a section.

As already mentioned, the sound insulation performance of automobile window glass tends to increase as the frequency of the sound increases, but moreover, for sound exceeding 600 Hz, the sound attenuation when transmitting through the window glass is 30 dB. It tends to exceed. Here, since the frequency f _c of the difference between the basic siren sound and the first additional siren sound is f _c ≦ 600 Hz, it is more easily transmitted through the window glass of the automobile and more easily reachable to people in the car. Sound in the range can be generated efficiently.

  A siren sound output device according to a sixth aspect of the present invention is the siren sound output device according to any one of the first to fifth aspects, wherein the sound generation unit includes a normal warning mode and a normal warning mode. Also have a first high warning mode with high warning performance. The sound generation unit generates a siren sound having the same frequency range as the basic siren sound in the normal warning mode, and generates the first synthesized siren sound in the first high warning mode.

  Here, the first synthetic siren sound that is easy to hear for both persons in the vehicle and pedestrians is generated in a first high warning mode different from the normal warning mode. Therefore, by using the first high warning mode, it is possible to reliably notify the surrounding people that the emergency vehicle is in a special situation with higher urgency such as when entering an intersection or passing through a traffic jam. As a result, safer and smoother emergency travel can be realized.

  A siren sound output device according to a seventh aspect of the present invention is the siren sound output device according to a sixth aspect, wherein the basic siren sound and the first synthesized siren sound gradually increase from the first frequency to the second frequency. And after the said 2nd frequency continues for a predetermined area, it has a period which falls gradually from the said 2nd frequency to the said 1st frequency. The ratio of the section in which the frequency changes between the first frequency and the second frequency is larger in the first high warning mode than in the normal warning mode.

  In general, a person can grasp a sense of movement and distance to some extent without using vision by changing the volume. Also, if the volume changes rapidly, a sense of urgency is created (hereinafter, such characteristics are referred to as “auditory time characteristics”). On the other hand, as described above, the human perceived volume depends on the frequency of sound. Here, in the first high warning mode, since the section in which the frequency of the siren sound is changed becomes longer, the volume of the siren sound is heard more dynamically by the human ear. Therefore, in the first high warning mode, a sense of urgency can be enhanced by the auditory time characteristics.

  The siren sound output device according to an eighth aspect of the present invention is the siren sound output device according to the sixth aspect, wherein the ratio of the high frequency section in the first high warning mode is the ratio of the high frequency section in the normal warning mode. Greater than percentage.

  In this case, in the first high warning mode, the high frequency section of the siren sound becomes long, so that the volume of human sensation increases and the warning performance of the siren sound can be further improved. Here, the “high frequency section” refers to “a section having a relatively high frequency in the period of the frequency change curve”. For example, when a period of a frequency change curve gradually rises from the first frequency to the second frequency, draws a curve that gradually falls from the second frequency to the first frequency after the second frequency continues for a predetermined period The section above the average of the first frequency and the second frequency can be called a “high frequency section”. In addition, when the first frequency continues for a predetermined interval and then has a cycle in which the second frequency higher than the first frequency continues for a predetermined interval, the predetermined interval where the second frequency continues is referred to as a “high frequency interval”. Can be called.

  A siren sound output device according to a ninth aspect of the present invention is the siren sound output device according to any of the sixth to eighth aspects, wherein the period of the frequency change curve in the first high warning mode is It is shorter than the period of the frequency change curve in the normal warning mode.

  Here, in the first high warning mode, the period of the frequency change curve of the siren sound is shortened and the frequency change becomes intense, so that the volume of the siren sound is heard more dynamically by the human ear. Therefore, in the first high warning mode, a sense of urgency can be enhanced by the auditory time characteristics.

  A siren sound output device according to a tenth aspect of the present invention is the siren sound output device according to any of the sixth aspect to the ninth aspect, further comprising a warning light control unit. The warning light control unit blinks the warning light in a normal warning pattern in the normal warning mode, and in the first high warning mode, the warning light in a first high warning pattern different from the normal warning pattern. Make the light blink.

  Here, not only the siren sound but also the warning pattern by the warning light changes according to the warning mode. Accordingly, it is possible to reliably notify the surrounding people that the emergency vehicle is in a special situation such as when entering an intersection or passing through a traffic jam.

  A siren sound output device according to an eleventh aspect of the present invention is the siren sound output device according to any of the sixth to tenth aspects, wherein the sound generation unit has higher warning performance than the normal warning mode. And a second high warning mode different from the first high warning mode. In the second warning mode, the sound generation unit generates a second synthesized siren sound obtained by adding a second additional siren sound to a siren sound having the same frequency range as the basic siren sound.

  Here, apart from the normal warning mode, at least two warning modes with higher alerting power and higher warning performance are prepared. Therefore, it is possible to deal with various special situations such as when an emergency vehicle enters an intersection or passes through a traffic jam.

According to the present invention, the basic siren sound frequency f _a, by outputting a first sound obtained by combining the additional siren sound frequency f _b, also the treble and bass both sound than the basic Siren Can be generated. The frequency f _b satisfy the relationship of f _a <f _b <2f _a and f _a + 20Hz ≦ f _b. As a result, it is possible to efficiently generate a siren sound that can be easily heard by people in the vehicle and pedestrians with a small amount of additional sound.

1 is an overall configuration diagram of a siren sound output system including a siren sound output device according to an embodiment of the present invention. Functional block diagram of the siren sound output system. The graph which shows the time change of the frequency of the siren sound in normal warning mode. The graph which shows the time change of the frequency of the siren sound in intersection approach mode. The graph which shows the time change of the frequency of the siren sound in traffic jam passing mode.

Hereinafter, a siren sound output device according to an embodiment of the present invention will be described with reference to the drawings.
<1. Overall configuration>
FIG. 1 is an overall configuration diagram of a siren sound output system 100 including a siren sound output device 1 according to the present embodiment, and FIG. 2 is a functional block diagram thereof. The siren sound output device 1 is mounted in an emergency vehicle such as a fire engine, an ambulance, or a police car, and outputs a siren sound for alerting the surroundings through a speaker 2.

  As shown in FIGS. 1 and 2, the siren sound output device 1 is connected to a warning light 3 and a microphone 4 in addition to a speaker 2. The siren sound output device 1 can also output audio input via the microphone 4 via the speaker 2. The siren sound output device 1 can also control blinking of the warning light 3. The speaker 2 and the warning light 3 are provided outside the emergency vehicle, for example, on the roof or side of the vehicle body. The microphone 4 is disposed in the vehicle so that a person in the vehicle can easily use it. The warning light 3 can be any vehicle-mounted warning light in addition to the diffused warning light. In the present embodiment, the warning light 3 includes a plurality of LEDs 3A arranged as appropriate, and also includes a CPU 30 for independently controlling the timing of turning on / off the LEDs 3A.

  The siren sound output device 1 has a plurality of warning modes for blowing different siren sounds. Specifically, the siren sound output device 1 is equipped with a high warning mode for outputting a siren sound having a higher warning property in addition to a normal warning mode for outputting a normal siren sound. The siren sound in the normal warning mode is a siren sound (restricted sound) having a frequency defined by laws and regulations. As will be described in detail later, the siren sound in the high warning mode is a synthesized sound obtained by adding a siren sound having a frequency different from that of the limit sound.

  In the present embodiment, the siren sound output device 1 is equipped with an intersection approach mode used when an emergency vehicle enters an intersection and a traffic jam passage mode used when passing a traffic jam as high warning modes. The siren sound in the intersection approach mode and the traffic jam passing mode is designed to be a siren sound that is easier to hear for both persons in the vehicle and pedestrians than the siren sound in the normal warning mode. Accordingly, it is possible to reliably convey to the surrounding people that the emergency vehicle is in a special situation with a high degree of urgency, such as when entering an intersection or passing through a traffic jam, thereby realizing safer and smoother emergency travel. In particular, in the intersection approach mode, for the purpose of performing a more appropriate alert to a relatively near area of an emergency vehicle equipped with the siren sound output system 100, and in the traffic jam passing mode, to a relatively far front of the vehicle. Yes. In the intersection approach mode, siren sounds necessary for alerting are transmitted to the driver of the vehicle provided with the sound insulation glass around the emergency vehicle. In the traffic jam passing mode, attention is given to a driver or a pedestrian in a relatively remote place by transmitting a siren sound that can suppress a decrease in sound pressure due to air attenuation.

<2. Detailed configuration of siren sound output device>
Hereinafter, a detailed configuration of the siren sound output device 1 will be described. As shown in FIG. 1, the siren sound output device 1 includes a housing 8 having a shape that is easy to install in a vehicle, for example, a rectangular parallelepiped shape, and further includes a CPU 10 and a storage unit 20 in the housing 8 (FIG. 1). 2). Operation switches 50 to 54 and a jog dial 55 are arranged on the front face surface 8A of the housing 8 that is easily accessible by persons in the vehicle. A microphone input terminal 40 for connecting an external microphone 4 is also disposed on the front face surface 8A. On the other hand, connection terminals (not shown) for connecting the external speaker 2 and the warning light 3 are obstructed by the wirings 6 and 7 between the peripheral devices 2 and 3 and the siren sound output device 1. It arrange | positions at the back surface, side surface, etc. of the housing | casing 8 so that it may not become.

  As shown in FIG. 2, an amplifier 60 is also mounted in the housing 8. The amplifier 60 is a circuit for amplifying the sound signal sent from the CPU 10 and sending it to the speaker 2. The microphone input terminal 40 is connected to both the amplifier 60 and the CPU 10. Therefore, the voice (mainly human voice) input from the microphone 4 can be directly output from the speaker 2 via the amplifier 60, and after being converted into a voice file by the CPU 10, stored in the storage unit 20. You can also keep it. As a result, voices of frequently used words can be recorded in the storage unit 20 in advance, and then reproduced through the speaker 2 by appropriately performing a switch operation or the like.

  The CPU 10 and the storage unit 20 are connected via a bus line, and the CPU 10 can read various data in the storage unit 20. The CPU 10 operates as the mode determination unit 11, the sound generation unit 12, and the warning light control unit 13 by reading and executing a program stored in the storage unit 20. The operation of each unit 11 to 13 will be described later.

  The storage unit 20 is a non-volatile storage device including a hard disk, a flash memory, and the like. In the storage unit 20, data (hereinafter, frequency parameter data) 21 </ b> A to 21 </ b> C defining the frequency of the siren sound are stored in addition to the above-described program. The frequency parameter data 21A is used in the normal warning mode, the frequency parameter data 21B is used in the intersection approach mode, and the frequency parameter data 21C is used in the traffic jam passing mode. As will be described later, the frequency changes with time, but the frequency parameter data 21A to 21C includes data defining the frequency change with time.

  The storage unit 20 also stores speech files 23A to 23C for words and data files (hereinafter referred to as flashing pattern files) 22A to 22C indicating flashing patterns of the warning light 3. The audio file 23A is used in the normal warning mode, the audio file 23B is used in the intersection approach mode, and the audio file 23C is used in the traffic jam passing mode. Similarly, the blinking pattern file 22A is used in the normal warning mode, the blinking pattern file 22B is used in the intersection approach mode, and the blinking pattern file 22C is used in the traffic jam passing mode.

  In the storage unit 20, voice files of many words (including voice files recorded through the microphone 4 using the recording function described above) are stored as original data of the voice files 23A to 23C. Yes. By operating the jog dial 55, the user can set appropriate ones among these many sound files as the sound files 23A to 23C for the normal warning mode, the intersection approach mode, and the traffic jam passing mode. .

  The operation switch group on the front face surface 8A includes a siren switch 50, a warning light switch 51, an intersection switch 52, a traffic jam switch 53, and an audio reproduction switch 54. The siren switch 50 is a switch for operating switching of output / stop of siren sound. The warning light switch 51 is a switch for operating switching of turning on / off of the warning light 3. The intersection switch 52 is a switch for operating ON / OFF switching of the intersection approach mode. The traffic jam switch 53 is a switch for operating ON / OFF switching of the traffic jam mode. The audio reproduction switch 54 is a switch for reproducing the audio file 23. The jog dial 55 can be used to adjust the volume of the speaker 2. The operation switches 50 to 54 and the jog dial 55 are connected to the CPU 10, and the CPU 10 can detect user operations on the operation switches 50 to 54 and the jog dial 55.

<3. Siren sound>
Hereinafter, details of the siren sound in the normal warning mode, the intersection approach mode, and the traffic jam passing mode will be described in order. In the following, a siren sound for a fire engine will be described as an example, but the same design concept can be applied to a siren sound for other emergency vehicles such as an ambulance or a police car.

<3-1. Siren sound in normal warning mode>
First, the siren sound in the normal warning mode will be described with reference to FIG. FIG. 3 is a graph (for one cycle) showing a temporal change in the frequency of the siren sound in the normal warning mode according to the present embodiment. The siren sound in the normal warning mode includes a siren sound (hereinafter referred to as a normal siren sound) that is a limit sound defined by laws and regulations as indicated by a solid line in FIG. As the frequency parameter data 21A referred to in the normal warning mode, only the frequency of the normal siren sound is stored. However, as shown by a broken line in FIG. 3, when a siren sound is output via the speaker 2 by the CPU 10 in accordance with the frequency parameter data 21A, the sound signal is transmitted through the internal circuit of the siren sound output device 1, the horn of the speaker 2, etc. By passing through, the second harmonic, the third harmonic, and so on of the normal siren sound are also generated.

The frequency f _a0 of the normal siren sound gradually increases from 320 Hz to 780 Hz, and after 780 Hz continues for a predetermined interval, has a cycle of gradually decreasing from 780 Hz to 320 Hz. Period T ₀ of the change curve of the frequency _a0, in the present embodiment is set such that T ₀ = 6 sec. The frequency of the second harmonic, the third harmonic,... Of the normal siren sound is 2f _a0 , 3f _a0,.

<3-2. Siren sound in intersection approach mode>
Next, the siren sound in the intersection approach mode will be described with reference to FIG. FIG. 4 is a graph (one cycle) showing a temporal change in the frequency of the siren sound in the intersection approach mode according to the present embodiment. As shown by the solid line in FIG. 4, the siren sound in the intersection approach mode is a first basic siren sound, which is a restricted sound determined by laws and regulations, and a first additional siren sound having a frequency different from that of the first basic siren sound. Synthetic siren sounds are included. As the frequency parameter data 21B referred to in the intersection approach mode, only the frequencies of the first basic siren sound and the first additional siren sound are stored. However, as shown by a broken line in FIG. 4, when the first synthesized siren sound is synthesized and output through the speaker 2 by the CPU 10 in accordance with the frequency parameter data 21B, the first basic siren sound and the second overtone of the first additional siren sound, 3 Overtones ... are also generated. In addition, since a plurality of sounds having different frequencies such as the first basic siren sound and the first additional siren sound are output from the speaker 2, in addition to the above harmonics as well as the above harmonics as shown in FIG. To do.

The first basic siren sound is a limit sound, similar to the normal siren sound in the normal warning mode, but in the present embodiment, both are slightly different. Although the difference will be described later, the frequency f _a1 of the first basic siren sound gradually increases from 320 Hz (first frequency) to 780 Hz (second frequency), similarly to the frequency f _a0 of the normal siren sound, and reaches 780 Hz. After a predetermined period, the period gradually decreases from 780 Hz to 320 Hz. That is, the first basic siren sound transitions in the same frequency range as the normal siren sound.

The frequency f _b1 of the first additional siren sound is set so that f _a1 <f _b1 <2f _a1 and f _a1 +20 Hz ≦ f _b1 . As shown in FIG. 4, in this embodiment, it is set to f _b1 = 1.7f _a1, the frequency f _b1 of the first additional siren sound from 544Hz (first frequency) to 1326Hz (second frequency) It rises gradually, and after 1326 Hz continues for a predetermined interval, it has a cycle of gradually falling from 1326 Hz to 544 Hz. As the second harmonic component of the first basic siren sound, a sound that transitions between 640 Hz and 1560 Hz is generated, and as the third harmonic component, a sound that transitions between 960 Hz and 2340 Hz is generated. The same applies to the fourth harmonic component and thereafter. In addition, as the second harmonic component of the first additional siren sound, a sound that transitions between 1088 Hz and 2652 Hz is generated, and as the third harmonic component, a sound that transitions between 1632 Hz and 3978 Hz is generated. The same applies to the fourth harmonic component and thereafter.

In general, the human audible region is said to be 20 Hz to 15 kHz. Among them, it is said that, in particular, sounds in the frequency range of 200 Hz to 5 kHz, more specifically 2 kHz to 4 kHz, are particularly easy to hear. Therefore, in the intersection approach mode, since the frequencies f _a1 and f _b1 are set as described above, in addition to the harmonic component of the first basic siren sound, the first additional siren sound and its harmonic component cause the human ear. In particular, high-frequency sounds that are particularly easy to hear are efficiently generated.

Further, since the frequency f _b1 is set as described above, the frequency f _c1 of the difference sound between the first basic siren sound and the first additional siren sound satisfies the relationship of 20 Hz ≦ f _c1 <f _a1 . Accordingly, it is possible for a person to hear with his / her ears and to generate a sound in a lower frequency range than the first basic siren sound. That is, it is possible to generate a sound that is more easily transmitted through the window glass of the automobile than the first basic siren sound, and it is possible to deliver the siren sound to the driver in the vehicle without being obstructed by the soundproofing property of the window glass.

Note that, as in the present embodiment where f _b1 = 1.7f _a1 , the frequency f _b1 of the first additional siren sound is set so that the first basic siren sound and the first additional siren sound do not generate a consonant sound. It is preferred that Moreover, it is preferable that any one of the difference sound of the frequency f _c1 and its harmonic, and the first basic siren sound, the first additional siren sound, and any of these harmonics are set so as not to generate a consonant sound.

Specifically, for example, when f _b1 = 1.25f _a1 or f _b1 = 1.5f _a1 , the frequency ratio between the first basic siren sound and the first additional siren sound is 4: 5 or 2 : 3. Accordingly, since the first basic siren sound and the first additional siren sound generate a consonant sound, it is preferable to avoid such a frequency as the frequency f _b1 . For example, when f _b1 = 1.75f _a1 , the frequency ratio between the difference sound (frequency: 0.75fa ₁ ) and the first basic siren sound is 3: 4, which is the second harmonic of the difference sound ( frequency: frequency ratio between 1.5f _a1) and the first base siren sound, 3: 2. Therefore, since the difference sound and its second overtone and the first basic siren sound generate a consonant sound, it is preferable to avoid such a frequency as the frequency f _b1 . With the above settings, it is possible to prevent the siren sound in the intersection approach mode from sounding comfortably in the ear and maintain the warning property of the siren sound. In addition, when the frequency f _b1 is set so that the sound components (including overtones and difference sounds) included in the siren sound in the intersection approach mode generate a dissonance, the warning performance of the siren sound can be further improved. it can.

Further, the frequency f _b1 of the first additional siren sound is preferably set so as to have a section where 1000 Hz ≦ f _b1 . This is because the harmonic component of the first additional siren sound can more efficiently generate a high-frequency sound of 2 kHz to 5 kHz that is particularly audible to human ears.

The frequency f _b1 of the first additional siren sound is preferably set so as to have a section where f _a1 +200 Hz ≦ f _b1 . That is, since there is a section where the frequency f _{c1 of} the difference sound is f _c1 ≧ 200 Hz, it is possible to more efficiently generate a low-frequency sound of 200 Hz or more that is particularly audible to human ears. It is. Therefore, the frequency f _b1 is set in such a numerical range, so that the siren sound can be delivered to the person in the vehicle more reliably. It is more preferable to set so that f _a1 +200 Hz ≦ f _b1 always.

Further, the frequency f _b1 of the first additional siren sound is preferably set so as to have a section where f _b1 ≦ f _a1 +600 Hz. In other words, there is a section where the frequency f _{c1 of} the difference sound is f _c1 ≦ 600 Hz, so that it is more easily transmitted through the window glass of the automobile. In general, it is said that the traffic noise in the vicinity of a place where a vehicle is traveling, such as in an intersection, is about 80 dB. Further, when traffic noise is viewed as white noise, it is difficult to recognize unless the sound has a sound pressure difference of +5 dB or more. Here, the sound pressure of the siren sound of the emergency vehicle is determined to be 120 dB or less at a point 20 m from the vehicle. That is, even if the maximum of 120 dB is used as a reference, if it is attenuated by 30 dB, it becomes 90 dB, and it becomes difficult for a person in the vehicle to recognize the further attenuation in traffic noise. In addition, the sound insulation performance of automobile window glass tends to increase as the frequency of sound increases. In addition, for sound exceeding 600 Hz, the sound attenuation when transmitting through the window glass is 30 dB. It tends to exceed. Therefore, by setting the frequency f _{b1 in the} numerical range as described above, the difference between the first basic siren sound and the first additional siren sound is more easily transmitted through the window glass of the automobile, so In addition, it is possible to efficiently generate a low-frequency sound that is easy to reach. In order to increase the perceived volume, it is more preferable that the frequency f _c1 of the difference sound is set so as to have a section having a frequency close to a higher frequency of 600 Hz. In addition to or instead of this, it is more preferable that the setting is always made so that f _b1 ≦ f _a1 +600 Hz (that is, f _c1 ≦ 600 Hz).

By the way, although sound waves are attenuated by propagating in the air, the degree of attenuation of frequency components exceeding 4 kHz, particularly exceeding 5 kHz is severe in an environment of 50% humidity. Therefore, setting the frequency f _b1 as described above is excellent also from the viewpoint that it is possible to efficiently generate such a sound with a frequency range of 5 kHz or less, particularly 4 kHz or less with little air attenuation. Yes.

In addition, many speaker horns mounted on emergency vehicles have a characteristic that they can strongly generate sound in the frequency range of 200 Hz to 9 kHz, particularly 700 Hz to 2 kHz. Therefore, setting the frequency f _b1 as described above is also excellent from the viewpoint that it is possible to efficiently generate sound in a frequency range that matches the characteristics of the horn.

In this embodiment, as can be seen by comparing FIG. 3 and FIG. 4, the period T ₁ of the change curve of the frequencies f _a1 and f _b1 in the intersection approach mode is the period T of the change curve of the frequency a ₀ in the normal warning mode. It is set to be shorter than ₀ and T ₁ = 5 seconds. Of course, 3 seconds, 4 seconds, 5.5 seconds, etc. are also possible. Thereby, in the intersection approach mode, the frequency changes more rapidly than in the normal warning mode, and the volume of the siren sound is heard more dynamically by the human ear. Therefore, in the intersection approach mode, a sense of urgency can be enhanced by auditory time characteristics.

  In the present embodiment, as can be seen by comparing FIGS. 3 and 4, the ratio of the high frequency section in the intersection approach mode is larger than the ratio of the high frequency section in the normal warning mode. Therefore, in the intersection approach mode, the high frequency section of the siren sound becomes longer than in the normal warning mode, so that the human perceived sound volume can be increased and the warning performance of the siren sound can be further enhanced. The “high frequency section” refers to a section having a relatively high frequency in the period of the frequency change curve, and here, the lowest frequency (first frequency) and the highest frequency (second frequency). It is a section that is more than the average value of.

<3-3. Siren sound in traffic passing mode>
Next, the siren sound in the traffic jam passing mode will be described with reference to FIG. FIG. 5 is a graph (for one cycle) showing a temporal change in the frequency of the siren sound in the traffic jam passing mode according to the present embodiment. As shown by the solid line in FIG. 5, the siren sound in the traffic passage mode is a second basic siren sound that is a limit sound determined by laws and regulations and a second additional siren sound having a frequency different from that of the second basic siren sound. Synthetic siren sounds are included. As the frequency parameter data 21C referred to in the traffic jam passing mode, only the frequencies of the second basic siren sound and the second additional siren sound are stored. However, as shown by the broken line in FIG. 5, when the second synthesized siren sound is synthesized and output via the speaker 2 by the CPU 10 according to the frequency parameter data 21C, the second basic siren sound and the second overtone of the second additional siren sound, Triple overtones ... are also generated. In addition, as shown by the one-dot chain line in FIG. 5, a plurality of sounds having different frequencies such as the second basic siren sound and the second additional siren sound are output from the speaker 2, and in addition to the above harmonics, these differential sounds are also generated. To do.

  As described above, the design concept of the siren sound in the traffic jam passing mode is substantially the same as the design concept of the siren sound in the intersection approach mode. However, siren sounds need only be delivered to people near the emergency vehicle when approaching an intersection, while siren sounds need to be delivered not only near the emergency vehicle but also far away when passing traffic. is there. That is, when approaching an intersection, the driver who should hear the siren sound is near the emergency vehicle, so the sound insulation of the window glass is not a problem as compared to when passing through a traffic jam. On the other hand, when passing through a traffic jam, it is important to consider that the volume of the siren sound is reduced due to air attenuation so that the driver can be surely alerted to a distant driver. Since the role of the traffic jam passing mode and the role of the intersection intrusion mode have such a difference in characteristics, there are differences as described later in the siren sound implemented in these warning modes. Hereinafter, siren sounds in the traffic jam passing mode will be described while comparing these warning modes.

The second basic siren sound is a limit sound, like the normal siren sound in the normal warning mode and the first basic siren sound in the intersection approach mode, but in the present embodiment, these sounds are slightly different. Although the difference will be described later, the frequency f _a2 of the second basic siren sound gradually increases from 320 Hz (first frequency) to 780 Hz (second frequency), similarly to the normal siren sound and the first basic siren sound. , 780 Hz continues after a predetermined interval, and then has a period of gradually decreasing from 780 Hz to 320 Hz. That is, the second basic siren sound transitions in the same frequency range as the normal siren sound and the first basic siren sound.

Similar to the first additional siren sound, the frequency f _b2 of the second additional siren sound is set so that f _a2 <f _b2 <2f _a2 and f _a2 +20 Hz ≦ f _b2 . However, it is preferable that the frequency f _b2 of the second additional siren sound is set lower than the frequency f _b1 of the first additional siren sound. This is because in the traffic jam passing mode, it is necessary to deliver a siren sound to a driver in a distant vehicle, so that a low-frequency sound that is more easily transmitted through the window glass is generated. In this sense, for the frequency f _b2 of the second additional siren sound, and more preferably _{f a2 <f b2 <1.5f a2} . On the other hand, when approaching intersections where sirens should be heard nearby, the sound insulation of the window glass is not a problem compared to when passing through traffic, so it is set to generate more high-frequency sounds. It becomes important to do. Therefore, it is more preferable that the frequency f _b1 of the first additional siren sound is 1.5f _a1 ≦ f _b1 <2f _a1 .

Specifically, in the present embodiment, as shown in FIG. 5, f _b2 = 1.4f _a2 is set. Accordingly, the frequency f _b2 of the second additional siren sound gradually increases from 448 Hz (first frequency) to 1092 Hz (second frequency), and after 1092 Hz continues for a predetermined period, the frequency f _b2 gradually decreases from 1092 Hz to 448 Hz. Have. As the second harmonic component of the second additional siren sound having the frequency f _b2 , a sound that transits between 896 Hz and 2184 Hz is generated, and as the third harmonic component, a sound that transits between 1344 Hz and 3276 Hz is generated. The same applies to the fourth harmonic component and thereafter. Accordingly, even in the traffic passing mode, since the frequencies f _a2 and f _b2 are set as described above, in addition to the harmonic component of the second basic siren sound, the second additional siren sound and its harmonic component cause High-frequency sounds that are particularly audible to the ear are efficiently generated.

Incidentally, as in this embodiment is f _b2 = 1.4f _a2, the frequency f _b2 of the second additional siren sound is also set to the second basic siren sound and a second additional siren produces no consonance It is preferred that Further, with any of the difference tone and its harmonics of the frequency f _c2, the second basic siren sound and the second additional siren sound and with any of these harmonics, it is preferably set to not generate consonance. Thereby, it is possible to prevent the siren sound in the traffic jam passing mode from resonating comfortably in the ear and to maintain the warning property of the siren sound. In addition, in order to improve the warning property due to the siren sound, the frequency f _b2 may be set so that sound components (including overtones and difference sounds) included in the siren sound in the traffic passing mode generate dissonance.

The frequency f _b2 of the second additional siren sound is also preferably set so as to have a section where f _a2 +200 Hz ≦ f _b2 . That is, since there is a section where the frequency f _{c2 of} the difference sound is f _c2 ≧ 200 Hz, it is possible to more efficiently generate a low-frequency sound of 200 Hz or more that is particularly audible to human ears. It is. In this sense, the condition that the difference sound is 200 Hz or more is particularly suitable for the traffic jam passing mode in which it is important to make the siren sound heard by a driver in a distant vehicle. It is more preferable to set so that f _a2 +200 Hz ≦ f _b2 is always satisfied.

Furthermore, it is preferable that the frequency f _b2 of the first additional siren sound is also set so as to have a section where f _b2 ≦ f _a2 +600 Hz. That is, because there is a section where the frequency f _{c2 of} the difference sound is f _c2 ≦ 600 Hz, it is easier to transmit through the window glass of the automobile. In this sense, the condition that the difference sound is 600 Hz or less is particularly suitable for the traffic jam passing mode in which it is important to let the driver in a distant car hear the siren sound. In order to increase the perceived volume, it is more preferable that the frequency f _c2 of the difference sound is set so as to have a section having a frequency close to a higher frequency of 600 Hz. In addition to or instead of this, it is more preferable that the setting is always made so that f _b2 ≦ f _a2 +600 Hz (that is, f _c2 ≦ 600 Hz).

Also, the frequency f _b2 of the second additional siren sound is preferably set so as to have a section where 1000 Hz ≦ f _b2 . This is because the harmonic component of the second additional siren sound can more efficiently generate a high-frequency sound of 2 kHz to 5 kHz that is particularly audible to the human ear. Note that the condition that the additional sound is 1000 Hz or more is a condition for generating a sound in a higher sound range, and is therefore more suitable for the intersection approach mode than for the traffic jam passing mode.

In addition, setting the frequency f _b2 as described above effectively generates sound in a frequency range of 5 kHz or less, particularly 4 kHz or less with less air attenuation, or in a frequency range that matches the characteristics of the horn. From the viewpoint of being able to

Further, in this embodiment, as can be seen by comparing FIGS. 3 and 5, the period T ₂ of the change curve of the frequencies f _a2 and f _b2 in the traffic passage mode is also the period T of the change curve of the frequency _a0 in the normal warning mode. It is set to be shorter than ₀ and T ₂ = 5 seconds. Of course, 3 seconds, 4 seconds, 5.5 seconds, etc. are also possible. Thereby, in the traffic jam passing mode, the frequency changes more rapidly than in the normal warning mode, and the volume of the siren sound is heard more dynamically by the human ear. Therefore, in the traffic jam passing mode, the sense of urgency can be enhanced by the auditory time characteristics.

  In the present embodiment, as can be seen by comparing FIG. 3 and FIG. 5, the ratio of the section in which the frequency changes between the lowest frequency (first frequency) and the highest frequency (second frequency) is normally Longer in the traffic jam mode than in the warning mode. Therefore, also from this, in the traffic jam passing mode, the volume of the siren sound is heard more dynamically by the human ear than in the normal warning mode. Therefore, in the traffic jam passing mode, the sense of urgency can be further enhanced by the auditory time characteristics.

<4. Operation of siren sound output device>
Hereinafter, the operation of the siren sound output apparatus 1 will be described. As described above, the crew of the emergency vehicle can operate the siren sound output device 1 to output siren sound and verbal sound from the speaker 2 and to blink the warning light 3. At this time, the siren sound, the sound of words, and the blinking pattern of the warning light 3 depend on the currently set warning mode.

  The currently set warning mode is determined by the mode determination unit 11 in real time. The default warning mode is the normal warning mode, but when the intersection switch 52 is pressed by the user, the mode is switched to the intersection approach mode, and the mode determination unit 11 determines that. The same applies to the traffic congestion switch 53. When the traffic congestion switch 53 is pressed by the user, the traffic congestion switching mode is switched to, and the mode determination unit 11 determines that. Further, when the intersection switch 52 is further pressed when the intersection approach mode is set, and when the traffic congestion switch 53 is further pressed when the traffic congestion mode is set, the normal warning mode is set. Return to.

  The crew member presses the siren switch 50 when he / she wants to generate a siren sound. In response to the depression of the siren switch 50, the sound generator 12 generates a siren sound according to the currently set warning mode. Specifically, the frequency parameter data 21A is read from the storage unit 20 in the normal warning mode, the frequency parameter data 21B in the intersection approaching mode, and the frequency parameter data 21C in the traffic jam passing mode. The sound of the frequency prescribed | regulated to these is repeatedly produced | generated. The siren sound generated by the sound generator 12 is output from the speaker 2 after being amplified by the amplifier 60. The siren sound is stopped when the siren switch 50 is further pressed during the siren sound. Note that when the mode determination unit 11 detects that the warning mode has been switched during the siren sounding, the sound generation unit 12 determines that the different frequency parameter data 21A to 21C corresponding to the switched warning mode. To output a siren sound.

  In addition, the crew member presses the sound reproduction switch 54 when he / she wants to reproduce the sound of the words registered for each warning mode. In response to the depression of the sound reproduction switch 54, the sound generator 12 generates a sound of words corresponding to the currently set warning mode. Specifically, the audio file 23A is read from the storage unit 20 in the normal warning mode, the audio file 23B in the intersection approach mode, and the audio file 23C in the traffic jam passing mode. Played once. The sound reproduced by the sound generator 12 is amplified by the amplifier 60 and output from the speaker 2.

  The crew member presses the warning light switch 51 when he wants to blink the warning light 3. When the warning light switch 51 is pressed, the warning light control unit 13 causes the warning light 3 to blink with a blinking pattern corresponding to the currently set warning mode. Specifically, the warning light control unit 13 uses the blinking pattern file 22A in the normal warning mode, the blinking pattern file 22B in the intersection approach mode, and the blinking pattern file 22C in the traffic jam passing mode. Are read from the storage unit 20. Subsequently, the warning light control unit 13 instructs the CPU 30 of the warning light 3 to blink the LED 3A with the blinking pattern as defined in the read blinking pattern files 22A to 22C. The blinking of the LED 3A stops when the warning light switch 51 is further pressed while the LED 3A is blinking. When the mode determination unit 11 detects that the warning mode is switched while the LED 3A is blinking, the warning light control unit 13 stores the blinking pattern files 22A to 22C corresponding to the switched warning mode. Read and change the blinking pattern.

  When the crew member wants to make an announcement from the speaker 2, he turns on the switch of the microphone 4. While the switch of the microphone 4 is set to ON, the sound input to the microphone 4 is amplified by the amplifier 60 and then flows from the speaker 2.

  The above siren sound output, verbal sound output, and blinking operation of the warning light 3 can be performed in any combination and simultaneously. Therefore, for example, while outputting a siren sound, the warning light 3 can be blinked, and a voice of words can be output simultaneously.

<5. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, the following changes can be made. Moreover, the gist of the following modifications can be combined as appropriate.

<5-1>
The above-described intersection approach mode and traffic jam passing mode are examples of the high warning mode. As the high warning mode, it is possible to set a mode for other special situations, for example, a right turn mode or a left turn mode.

<5-2>
The number of high warning modes is not limited to two and may be one or three or more. Moreover, it is also possible to mount the synthetic siren sound according to the present invention in the normal warning mode without or providing the high warning mode. That is, the synthetic siren sound according to the present invention can be applied in any warning mode (including a case where there is no warning mode switching).

<5-3>
The first synthetic siren sound is not limited to that described above. For example, the first synthetic siren sound may be not only the first basic siren sound and the first additional siren sound but also other additional sounds superimposed. The same applies to the second synthetic siren sound. In addition to or instead of this, the siren sound in the normal warning mode does not have to be composed of only the normal siren sound. For example, the siren having the frequency that forms the normal siren sound and the consonant sound is not necessary. It may be a synthesized sound with sound.

<5-4>
In the above embodiment, the first and second basic siren sounds used in the intersection approach mode and the traffic jam passing mode may be different in frequency change period and / or have the same high frequency section ratio. It may be. In addition to or instead of this, the first and second basic siren sounds used in the intersection approach mode and the traffic jam mode and the normal siren sound in the normal warning mode may be a frequency change period and / or a high frequency. The ratio of the sections may be the same.

<5-5>
In the above embodiment, the flashing pattern of the warning light 3 is configured to be linked to the warning mode, but can be configured to flash in the same flashing pattern without being linked to the warning mode. In addition to or instead of this, it is also possible to configure the voice of words in the storage unit 20 not to be linked to the warning mode.

<5-6>
In the above embodiment, the frequency data of the siren sound is stored in the storage unit 20, and the sound generation unit 12 refers to the data to generate the siren sound. However, the mode of generation of the siren sound by the sound generation unit 12 is not limited to this. For example, a sound data file in which a siren sound is programmed may be stored in the storage unit 20, and the sound generation unit 12 may reproduce the file when the siren sound is generated. In this case, one sound data file obtained by synthesizing the first basic siren sound and the first additional siren sound can be prepared as the sound data file for the intersection approach mode. Separate sound data files can be prepared for the additional siren sounds, and these can be reproduced synchronously. The same applies to the traffic passing mode.

DESCRIPTION OF SYMBOLS 1 Siren sound output device 2 Speaker 12 Sound generation part 13 Warning light control part

Claims (11)

A siren sound output device for outputting a siren sound for an emergency vehicle from a speaker,
A sound generation unit for generating a first synthetic siren sound obtained by adding a first additional siren sound to a basic siren sound;
When the frequency of the basic siren sound is f _a and the frequency of the first additional siren sound is f _b ,
f _a <f _b <2f _a and f _a +20 Hz ≦ f _b
Siren sound output device. The frequency f _b is set so that the basic siren sound and the first additional siren sound do not generate a consonant.
The siren sound output device according to claim 1. The first additional siren sound has a section where 1000 Hz ≦ f _b .
The siren sound output device according to claim 1 or 2. The first additional siren sound has a section satisfying f _a +200 Hz ≦ f _b .
The siren sound output device according to any one of claims 1 to 3. The first additional siren sound has a section where f _b ≦ f _a +600 Hz.
The siren sound output device according to any one of claims 1 to 4. The sound generation unit has a normal warning mode and a first high warning mode having a higher warning property than the normal warning mode, and generates a siren sound in the same frequency range as the basic siren sound in the normal warning mode. And generating the first synthesized siren sound in the first high warning mode,
The siren sound output device according to any one of claims 1 to 5. The basic siren sound and the first synthetic siren sound gradually increase from the first frequency to the second frequency, and after the second frequency continues for a predetermined interval, gradually decrease from the second frequency to the first frequency. Has a period,
The ratio of the section in which the frequency changes between the first frequency and the second frequency is larger in the first high warning mode than in the normal warning mode,
The siren sound output device according to claim 6. The ratio of the high frequency section in the first high warning mode is larger than the ratio of the high frequency section in the normal warning mode,
The siren sound output device according to claim 6. The period of the frequency change curve in the first high warning mode is shorter than the period of the frequency change curve in the normal warning mode.
The siren sound output device according to any one of claims 6 to 8. A warning light control that causes the warning light to blink in a normal warning pattern in the normal warning mode and that causes the warning light to blink in a first high warning pattern different from the normal warning pattern in the first high warning mode. Further comprising
The siren sound output device according to any one of claims 6 to 9. The sound generator has a second high warning mode that is higher in warning than the normal warning mode and different from the first high warning mode, and is the same as the basic siren sound in the second warning mode. A second synthesized siren sound is generated by adding the second additional siren sound to the frequency range siren sound;
The siren sound output device according to any one of claims 6 to 10.

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