Hearing sound acquisition method and hearing sound acquisition device

Abstract

To acquire the sound pressure of the uttered sound heard by conference participants in a conference system.SOLUTION: A hearing sound acquisition method acquires the sound pressure at a hearing position of a listener in a loudspeaker system for delivering the uttered sound of a speaker to the listener via a loudspeaker transmission path including sound collection means, amplification means and sound-emitting means. The uttered sound is delivered to the listener via a direct transmission path not including the loudspeaker transmission path. The hearing sound acquisition method acquires the sound pressure at an arbitrary position on a transmission path of the uttered sound and determines the sound pressure at the hearing position of the listener on the basis of the acquired sound pressure.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method and an apparatus for acquiring audible sound. [Background technology]

[0002] In a conference system, a means for amplifying speech sounds and transmitting them to conference participants is provided in the conference room so that all conference participants can clearly hear the speech sounds. In this type of conference system, it is necessary to amplify the speech sounds of the speaker so that the speech sounds reach the listeners with sufficient sound pressure. Patent Document 1, which relates to remote control, discloses a technology for notifying the implementation status of amplification in an area where speech sounds are amplified. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-245365 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 only notifies the implementation status of sound amplification, and even if this notification is received, it is difficult to determine whether the speech sound is reaching the listener with sufficient sound pressure.

[0005] One embodiment of the present invention has been made in consideration of the above circumstances, and has an object to provide a method for acquiring audible sound that acquires the sound pressure of an uttered sound. [Means for solving the problem]

[0006] A method for acquiring audible sounds according to an embodiment of the present invention obtains a sound pressure at a listening position of a listener in a loudspeaker system that delivers a speech sound of a speaker to a listener via a loudspeaker transmission path including a sound collection means, an amplification means, and a sound emission means. The speech sound reaches the listener via a direct transmission path that does not include the loudspeaker transmission path. The method for acquiring audible sounds obtains a sound pressure at an arbitrary position on the transmission path of the speech sound, and obtains a sound pressure at the listening position of the listener based on the obtained sound pressure. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a configuration of a conference system and an audible sound acquisition device that executes a method for acquiring audible sound according to an embodiment of the present invention; [Diagram 2] 2 is a block diagram showing a hardware configuration of audible sound acquisition device 200. FIG. [Diagram 3] FIG. 2 is a diagram showing an example of the configuration of a speech sound transmission system in the embodiment. [Figure 4] FIG. [Diagram 5] 13 is a block diagram showing a method for acquiring audible sounds in the transfer system. FIG. [Figure 6] FIG. 2 is a generalized block diagram of a speech sound transmission system in the embodiment. [Figure 7] FIG. 2 is a block diagram showing a transmission path constituting the transmission system. [Figure 8] 13 is a block diagram showing a method for acquiring audible sounds in the transfer system. FIG. [Figure 9] FIG. 13 is a diagram illustrating an example of an information providing unit in the embodiment. [Figure 10] 11 is a flowchart of a listening sound acquisition process executed in the embodiment. [Figure 11] FIG. 13 is a block diagram showing a method for acquiring audible sounds according to another embodiment of the present invention. [Figure 12] FIG. 13 is a diagram showing a modified example of visible information. [Figure 13] FIG. 13 is a diagram showing a modified example of visible information. [Figure 14] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] FIG. 1 is a block diagram showing the configuration of an audible sound acquiring device 200 and a loudspeaker system 100 that executes a method for acquiring audible sounds according to an embodiment of the present invention.

[0010] The method for acquiring audible sounds according to this embodiment is directed to a loudspeaker system 100 shown in Fig. 1. The loudspeaker system 100 of this embodiment is a system that loudspeaks the voice of a speaker and delivers the voice to listeners, and is used, for example, in conferences, seminars, presentations, and the like. In this embodiment, an example is shown in which the loudspeaker system 100 is used in a conference. In the loudspeaker system 100, the speech sound of a conference participant Mi who is a speaker reaches a conference participant Mj who is a listener via a loudspeaker transmission path 10 including a sound collection means 11, an amplification means 12, and a sound emission means 13, and the speech sound also reaches the conference participant Mj via a direct transmission path 20 that does not include the loudspeaker transmission path 10.

[0011] In such a loudspeaker system 100, the audible sound acquisition device 200 acquires the sound of the conference participant M, who is a listener. j 1 as an external device of the loudspeaker system 100, it may be a device included in a control device (not shown) of the loudspeaker system 100.

[0012] 2 is a block diagram showing a hardware configuration of the audible sound acquisition device 200. The audible sound acquisition device 200 is, for example, a general-purpose information processing device such as a personal computer or a smartphone. The general-purpose information processing device may be a device used by a speaker, or may be a device used by an operator who manages a conference or an installer who installs a conference system.

[0013] The audio acquisition device 200 includes a display 251 , a user I / F 252 , a flash memory 253 , a CPU 254 , a RAM 255 , and a communication I / F 256 .

[0014] The display 251 is, for example, an LCD or an OLED, and displays various information. The user I / F 252 is, for example, a touch panel that is laminated on the LCD or OLED of the display 251. Alternatively, the user I / F 252 may be a keyboard or a mouse. When the user I / F 252 is a touch panel, the user I / F 252 and the display 251 configure a GUI (Graphical User Interface).

[0015] The communication I / F 256 is a communication means such as a wireless LAN, Bluetooth (registered trademark), etc. The communication I / F 256 receives a sound signal from the loudspeaker system 100, for example.

[0016] The CPU 254 is an example of a processor, and is a control unit that controls the operation of the audible sound acquisition device 200. The CPU 254 performs various operations by reading out a predetermined program, such as an application program, stored in a flash memory 253, which is a storage medium, into the RAM 255 and executing the program. The CPU 254 of this embodiment realizes the functions of the control unit 201, the measurement unit 202, and the information providing unit 203 shown in FIG. 1. The program may be stored in a server (not shown). The CPU 24 may download the program from the server via a network and execute the program.

[0017] As shown in Fig. 1, the heard sound acquisition device 200 includes a control unit 201, a measurement unit 202, and an information providing unit 203. Here, the measurement unit 202 is a means for measuring the sound pressure at an arbitrary position on the transmission path of the speech sound in the loudspeaker system 100. The control unit 201 includes a processor, a non-volatile memory that stores a program executed by the processor, a volatile memory used as a work area by the processor, etc. This control unit 201 calculates the sound pressure of the conference participant M who is a listener by calculation using the sound pressure measured by the measurement unit 202.j The control unit 201 also determines the relationship of the sound pressure of the speech sound to an appropriate value based on the sound pressure at the listening position, and provides visible information indicating the determination result via the information providing unit 203.

[0018] Fig. 3 is a diagram showing an example of a transfer system for speech sounds in the public address system 100. Fig. 4 is a block diagram expressing the same transfer system by a transfer function.

[0019] In this example, a microphone 11a as the sound collection means 11, an amplifier 12a as the amplification means 12, and a speaker 13a as the sound emission means 13 are arranged on a ceiling 301 of a conference room 300. i The audio is transmitted from the speaking position (for example, the head position) of the conference participant M via the microphone 11a, the amplifier 12a, and the speaker 13a. j The route from the speaker to the listening position (for example, the head position) of the conference participant M is the amplification transmission route 10. i From the speaking position of conference participant M j The path from the first speaker to the listening position is the direct path 20.

[0020] In this example, if the sound pressure of the speech sound at the speaking position is sp0, the transfer function from the speaking position to the sound pickup section of microphone 11a is H2, the total gain of microphone 11a, amplifier 12a, and speaker 13a is G, and the transfer function from the sound emission section of speaker 13a to the listening position is H3, the sound pressure sp4 of the sound that reaches the listening position via amplifier transfer path 10 is given by the following equation.

[0021] sp4 = H2 G H3 sp0 ……(1) On the other hand, if the transfer function of the direct transfer path 20 is H1, the sound pressure sp1 of the sound that reaches the listening position via the direct transfer path 10 is expressed by the following equation.

[0022] sp1 = H1 · sp0 ……(2) Therefore, the sound pressure sp5 of the sound heard at the listening position is given by the following formula.

[0023] sp5=sp1+sp4 =(H2·G·H3+H1)·sp0 ……(3) In the transfer system shown in FIGS. 3 and 4, if the input sound pressure of the microphone 11a is sp2, this sound pressure sp2 is the sound pressure at a position on the transfer path of the speech sound and is expressed by the following formula.

[0024] sp2 = H2·sp0 ……(4) Here, the sound pressure sp0 can be calculated backward from the sound pressure sp2 using the following formula:

[0025] sp0=H2 -1 sp2 ……(5) Therefore, the control unit 201 of the heard sound acquisition device 200 measures the sound pressure sp2 by the measurement unit 202, and performs the following calculation based on the measured sound pressure sp2 to obtain the sound pressure sp5 at the listening position.

[0026] sp5 = (H2 G H3 + H1) sp0 =(H2 G H3+H1) H2 -1 sp2 ……(6) FIG. 5 is a block diagram showing the calculation content of this equation (6).

[0027] Next, the function of the heard sound acquisition device 200 will be described in more general terms. Fig. 6 is a block diagram showing a transmission system of speech sounds in a loudspeaker system 100 in which the number of conference participants N is eight. In this loudspeaker system 100, normally, N conference participants M i One of the participants (i = 1 to N) will be the speaker, and the remaining N-1 participants will be the listeners. i N horizontal lines (N=8 in this example) connected to (i=1 to N) are shown. These horizontal lines are connected to the conference participants M i The figure also shows the propagation path of the sound uttered by the conference participants M (i = 1 to N). j N vertical lines are shown connected to the conference participants M j(j=1 to N) along the propagation path of the sound heard by the conference participants M i (i=1~N) and each horizontal line connected to the conference participant M j At each intersection of the vertical lines connected to (j=1 to N and j≠i), a transfer function H ij The transfer function H ij is the conference participant M i and M. j (j ≠ i) is a transfer function of a transfer path in which the amplifying transfer path 10 and the direct transfer path 20 interposed between the speakers are connected in parallel. i The speech sound is expressed by the transfer function H ij A conference participant M, who is a listener, j to reach.

[0028] Figure 7 shows the conference participant M i and M. j The transfer function H of the transfer path between (j ≠ i) ij In this embodiment, the transfer path includes a transfer path that transfers speech sound. Here, the transfer function Hm ij is the transfer function H ij where spm represents the sound pressure at an arbitrary position. This allows the heard sound acquisition device 200 to acquire the sound pressure (spm) at an arbitrary position on the transmission path of the speech sound, and to calculate the sound pressure at the listening position of the listener based on the acquired sound pressure. Specifically, if the heard sound acquisition device 200 can acquire the sound pressure spm, it can calculate the transfer function Hm ij Using the inverse function of the sound pressure sp i can be sought.

[0029] sp i =Hm ij ―1 spm ……(7) sp i Once this is found, sp j sp j =H ij ·sp i =H ij Hm ij―1 ·spm ……(8) Therefore, in this embodiment, the control unit 201 executes the calculation shown in the above formula (8) based on the sound pressure spm, and calculates the number of the conference participants M j Sound pressure sp at listening position (N-1 position) (j=1~N and j≠i) j Request.

[0030] FIG. 8 is a block diagram showing the calculation of equation (8).

[0031] The correspondence between this generalized embodiment and the above-mentioned embodiments of FIGS. 3 and 4 is, for example, as follows.

[0032] <Example 1: spm=sp2> spm=sp2 Hm ij =H2 sp i =sp0 sp j =sp5 H ij =H2 G H3 + H1 <Example 2: spm=sp4> spm=sp4 Hm ij =H2 G H3 sp i =sp0 sp j =sp5 H ij =H2 G H3 + H1 Using the above examples 1 and 2, if sound pressure is obtained at the position sp2, Hm ij =H2, and if sound pressure is obtained at the position of sp4, Hm ij =H2·G·H3. As described above, the inverse function Hm ij ―1 In this embodiment, in order to obtain the sound pressure at the listening position, i and M. j The transfer function H of the transfer path between (j ≠ i) ij and the transfer function Hmij In this embodiment, when the public address system 100 is installed, the conference participants M i The head positions of the (i=1 to N) are determined, and the characteristics of each part of the sound amplification transmission path 10 are optimized based on the head positions. ij and Hm ij Therefore, in this embodiment, when the public address system 100 is installed, the transfer function H ij and Hm ij is generated and stored in the non-volatile memory of the control unit 201. Then, when the public address system 100 is in operation, the control unit 201 uses the stored transfer function H ij and Hm ij This is used to obtain the sound pressure at the listening position.

[0033] In this embodiment, in order to obtain the sound pressure at the listening position, the conference participant M i The transfer function H ij and Hm ij Therefore, it is necessary to use the following: i It is necessary to identify the speaker. Various means are possible for detecting the speaker. For example, if the microphone 11a arranged in the conference room 300 is a microphone whose directivity can be controlled so as to pick up the speech sound with high gain, the speaker may be detected using this microphone. Also, if it is difficult to detect the speaker using the microphone 11a, for example, the speaker M i (i=1 to N) may be captured by a camera, and a recognition process may be performed on the captured image to detect a conference participant who is speaking.

[0034] When the control unit 201 acquires the sound pressures at the N-1 listening positions, it determines the relationship of the sound pressure of the speech sound to an appropriate value based on the acquired sound pressures, and provides visible information indicating the determination result via the information providing unit 203.

[0035] FIG. 9 is a diagram showing an example of the information providing unit 203. The information providing unit 203 has an appropriate lamp 203a with the word "appropriate" written on it, an under-stress lamp 203b with the word "under-stress" written on it, and an over-stress lamp 203c with the word "over-stress" written on it. In a preferred embodiment, the appropriate lamp 203a, the under-stress lamp 203b, and the over-stress lamp 203c are lit with different luminous colors. The information providing unit 203 is disposed, for example, near the sound emitting unit. The position at which the information providing unit 203 is disposed may be anywhere as long as it is a position where the speaker can easily confirm. For example, the position at which the information providing unit 203 is disposed may be a position where the speaker can easily see it when speaking. Specifically, if the information providing unit is disposed at the position of the speaker, the speaker can confirm that he or she is speaking with an appropriate sound pressure by looking at the speaker from which the sound is actually being emitted. Furthermore, if the information providing unit is placed at a position close to the speaker, the speaker can check his / her hand to confirm that the speaker is speaking at an appropriate sound pressure. For example, the information providing unit 203 may be placed at a position where the installer can easily check when installing the loudspeaker system. Specifically, if the information providing unit is provided on the screen of a computer used by the installer, the installer can easily check that the speaker is speaking at an appropriate sound pressure by checking his / her computer during the installation work.

[0036] When the sound pressures at all of the N-1 listening positions are within the appropriate range, the control unit 201 turns on the appropriate lamp 203a. When the sound pressure at at least one of the N-1 listening positions is below the lower limit of the appropriate range, the control unit 201 turns on the insufficient lamp 203b. In this case, the speaker increases the speech sound pressure. When the sound pressure at at least one of the N-1 listening positions is above the upper limit of the appropriate range, the control unit 201 turns on the excessive lamp 203c. In this case, the speaker decreases the speech sound pressure.

[0037] Next, the operation of this embodiment will be described. In this embodiment, the processor of the control unit 201 repeatedly executes the audible sound acquisition process P200 shown in FIG.

[0038] First, the processor of the control unit 201 judges whether or not speech has been detected (step S1). This judgment is made based on, for example, the sound collection state of the sound collection means 11 (specifically, whether or not speech sound is being collected, and which conference participant's speech sound is being collected). If the judgment result of step S1 is "NO", the processor of the control unit 201 repeats the judgment of step S1.

[0039] If the determination result in step S1 is "YES", the processor of the control unit 201 measures the sound pressure spm of the monitor sound at a position on the transmission path of the speech sound of the conference participant who is the speaker, using the measurement unit 202 (step S2).

[0040] Next, the processor of the control unit 201 selects the conference participant M who is the speaker. i The transfer function H ij and Hm ij -1 Using the sound pressure spm of the monitor sound obtained in step S2, the sound pressure SP j (j=1 to N and j≠i) is calculated (step S3).

[0041] Next, the processor of the control unit 201 calculates the sound pressure SP j Based on (j=1 to N and j≠i), the relationship of the sound pressure of the speech sound to the appropriate value is determined, and visual information indicating the determination result is provided to the speaker by the information providing unit 203 (step S4). When step S4 ends, the process returns to step S1.

[0042] In this embodiment, the processes of steps S1 to S4 are repeated as described above. Then, when an utterance is made, the sound pressure at each listening position is calculated, and based on the calculation result, the relationship of the sound pressure of the utterance sound to the appropriate value is determined, and the determination result is shown to the speaker. Therefore, the speaker can change the utterance sound pressure so that the utterance sound reaches each listener with an appropriate sound pressure.

[0043] <Other embodiments> Although one embodiment of the present invention has been described above, other embodiments of the present invention are also possible. For example, the following embodiments are possible.

[0044] (1) In the above embodiment, the LISTENING SOUND ACQUISITION DEVICE 200 measures the sound pressure of the input sound of the sound collection means 11 (sp2 in FIG. 3), and obtains the sound pressure at the listening position by calculation based on the measured sound pressure. However, the LISTENING SOUND ACQUISITION DEVICE 200 may calculate the sound pressure at the listening position based on a sound pressure other than the sound pressure of the input sound of the sound collection means 11. For example, the LISTENING SOUND ACQUISITION DEVICE 200 may measure the sound pressure of the output sound of the sound emitting means 13 (sp3 in FIG. 3), and obtain the sound pressure at the listening position by calculation based on the measured sound pressure. Alternatively, the LISTENING SOUND ACQUISITION DEVICE 200 may measure the sound pressure of the input sound of the sound collection means 11 (sp2 in FIG. 3) and the sound pressure of the output sound of the sound emitting means 13 (sp3 in FIG. 3), and obtain the sound pressure at the listening position by calculation based on the measured sound pressure. Alternatively, the heard sound acquisition device 200 may measure the sound pressure of the speech sound at the speaking position (sp0 in FIG. 3), and obtain the sound pressure at the listening position by calculation based on this measured sound pressure.

[0045] (2) In the above embodiment, the audible sound acquisition device 200 uses a predetermined transfer function H ij and Hm ij -1 However, the sound pressure at the listening position was obtained by using a camera. iThe head positions (i=1 to N) (i.e., speaking position and listening position) of the participants may be obtained, and a transfer function of the transfer path between each of the conference participants may be generated based on these head positions. More specifically, the heard sound acquisition device 200 obtains the position of the wall of the room, the material (reflectance) of the wall of the room, the distance between the speaker and the sound collection means 11, the distance between the sound emitting means 13 and the listener, and the distance between the speaker and the listener. The heard sound acquisition device 200 obtains a transfer function H1 from the speaking position to the listening position based on the distance between the speaker and the listener, the positional relationship between the speaker and the wall, the positional relationship between the listener and the wall, and the reflectance of the wall. The heard sound acquisition device 200 obtains a transfer function H2 from the speaking position to the sound collection section of the microphone 11a based on the distance between the speaker and the sound collection means 11, the positional relationship between the speaker and the wall, the positional relationship between the sound collection means 11 and the wall, and the reflectance of the wall. The heard sound acquiring device 200 obtains a transfer function H2 from the speaking position to the sound collecting means 11 based on the distance between the speaker and the sound collecting means 11, the positional relationship between the speaker and the wall, and the reflectance of the wall.

[0046] (3) In the above embodiment, the sound acquisition device 200 calculates the sound pressure at the listening position, but it may be determined by selecting an appropriate one from a database (matrix, etc.) of measurements taken in advance. If the matrix is ​​set appropriately, multiple microphones and speakers may be used.

[0047] (4) As shown in Fig. 11, the heard sound acquisition device 200 may realize an AI (artificial intelligence) 250. In the embodiment shown in Fig. 11, each conference participant Mi (i = 1 to N) is made to speak in the loudspeaker system 100. At that time, the sound pressure spm of the monitor sound obtained from the loudspeaker system 100 and the sound pressure sp at the listening position are calculated. j The above data was fed to AI250 as training data, and the sound pressure spm of the monitor sound and the sound pressure sp at the listening position were calculated. j Then, when the public address system 100 is in operation, the AI ​​250 calculates the sound pressure sp at the listening position based on the sound pressure spm of the monitor sound obtained from the public address system 100. j We seek...

[0048] (5) The information providing unit 203 may be arranged in front of each conference participant Mi (i=1 to N), for example, corresponding to each conference participant Mi. In this embodiment, when a certain conference participant Mi is a speaker, the information providing unit 203 corresponding to the conference participant Mi provides visual information indicating the relationship of the speech sound pressure to the appropriate value.

[0049] (6) When there are a plurality of sound emitting means 13, the heard sound acquiring device 200 may arrange the information providing unit 203 in association with each sound emitting means 13.

[0050] (7) In the above embodiment, the heard sound acquiring device 200 determines the relationship of the speech sound pressure to the appropriate value based on the sound pressure at the listening position. However, the relationship may be determined based on a sound pressure other than the sound pressure at the listening position.

[0051] (8) In the above embodiment, the heard sound acquiring device 200 displays the relationship of the speech sound pressure to the appropriate value in three ranks, namely, too low, appropriate, and excessive, but may display in four or more ranks. Alternatively, the heard sound acquiring device 200 may display the speech sound pressure calculated from the sound pressure at the listening position as a bar graph (display as a continuous value) for each listening position.

[0052] (9) The gain of the sound amplification path 10 may be set in advance so that the sound amplification level is appropriate to a certain degree for the basic speech volume of a person. This allows the sound pressure required for appropriate sound amplification to be set within a reasonable range for the speaker.

[0053] (10) In the transmission system shown in Fig. 3, when the sound pressure sp1 of the sound reaching the listening position via the direct transmission path 10 is sufficiently small, the heard sound acquisition device 200 may ignore the sound pressure sp1 and set the sound pressure sp4 to be equal to the sound pressure sp5. For example, when the distance between the conference participant Mi and the conference participant Mj exceeds a predetermined threshold, the heard sound acquisition device 200 may ignore the sound pressure sp1 and set the sound pressure sp4 to be equal to the sound pressure sp5.

[0054] (11) FIG. 12 is a diagram showing a modified example of visible information. In this example, the audible sound acquisition device 200 provides the speaker with the sound pressure at the listening position as a sound pressure distribution on the display 251. The example of FIG. 12 shows the microphone 11a and the speaker 13a on a schematic diagram of a conference room viewed in plan. In addition, in the example of FIG. 12, the audible sound acquisition device 200 displays the sound pressure on the listening surface by the darkness of a color. For example, a darker color indicates a higher sound pressure, and a lighter color indicates a lower sound pressure. The audible sound acquisition device 200 may display the sound pressure on the listening surface by different colors. For example, the audible sound acquisition device 200 may display the color of a position with high sound pressure as red, and the color of a position with low sound pressure as blue.

[0055] 12 shows two microphones 11a, the eavesdropping sound acquisition device 200 may display different screens for the first microphone 11a and the second microphone 11a and display the sound pressure distribution for each microphone. The eavesdropping sound acquisition device 200 may also change the color of the sound pressure for each microphone. For example, the eavesdropping sound acquisition device 200 may display the sound pressure distribution with a red density for the first microphone 11a and the sound pressure distribution with a blue density for the second microphone 11a.

[0056] This allows the speaker to intuitively grasp at a glance the speech sound pressure reaching the conference room, making it easier to change the speech sound pressure so that the voice is delivered to the listeners at an appropriate sound pressure.

[0057] (12) The visible information may be an indicator such as an LED provided for each speaker. For example, the audible sound acquisition device 200 may cause the LED to glow blue when the sound pressure is too low. Also, the audible sound acquisition device 200 may cause the LED to glow red when the sound pressure is too high. Also, the audible sound acquisition device 200 may cause the LED to glow green when the sound pressure is appropriate. Also, the audible sound acquisition device 200 may change the brightness of the LED depending on the sound pressure. For example, the audible sound acquisition device 200 may cause the LED to be dark when the sound pressure is too low and brighten when the sound pressure is too high.

[0058] (13) The narrated sound acquiring device 200 may inform the user of the judgment result by audio sensory information. For example, the narrated sound acquiring device 200 may inform the user by audio such as "Please turn up the volume" when the sound pressure is too low, and may inform the user by audio such as "Please turn down the volume" when the sound pressure is too high.

[0059] (14) The eavesdropping sound acquiring device 200 may notify the judgment result by sensory information through vibration. In this case, the eavesdropping sound acquiring device 200 includes a vibration device carried by the speaker. The eavesdropping sound acquiring device 200 vibrates the vibration device when the sound pressure is too low or too high.

[0060] (15) FIG. 13 is a diagram showing a modified example of the visual information. In this example, the hearing sound acquisition device 200 provides the speaker with visual information showing the relationship of the sound pressure of the speech sound to the appropriate value by arranging indices that change in proportion to the magnitude of the sound pressure at multiple locations. More specifically, in this example, multiple ribbons 70a to 70e are arranged in front of the speaker 13a as indices. The multiple ribbons 70a to 70e hang down, for example, from the ceiling of the conference room. The multiple ribbons 70a to 70e each have a different color and physical property. The physical property includes, for example, the elastic modulus (hardness) or weight. The ribbon 70a has the lightest color and is the softest (or lightest). The ribbon 70e has the darkest color and is the hardest (or heaviest). Therefore, the ribbon 70a is the easiest to move. The ribbon 70a moves even when the sound pressure of the speaker 13a is low. The ribbon 70e is the hardest to move. The ribbon 70e moves when the sound pressure of the speaker 13a is high. That is, the higher the sound pressure of the speaker 13a, the more the ribbons 70a to 70e move in sequence. This allows the speaker to visually recognize the sound pressure by watching the movements of the ribbons 70a to 70e. For example, when the ribbon 70e moves, the speaker can determine that the sound pressure is excessive. On the other hand, when only the ribbon 70a moves, the speaker can determine that the sound pressure is too low.

[0061] (16) The LISTENER sound acquisition device 200 may obtain the sound pressure at any position on the transmission path from the level of the sound signal supplied to the speaker. Alternatively, the LISTENER sound acquisition device 200 may obtain the sound pressure at any position on the transmission path from the driving voltage of the speaker.

[0062] (17) The visible information may indicate the proportion of the portion of the room where the sound pressure is appropriate relative to the entire room. For example, when the proportion of the portion of the room where the sound pressure is appropriate is a predetermined value (e.g., 70%), the heard sound acquisition device 200 may display the fact that the sound pressure is appropriate using a display such as an LED, LCD, or OLED.

[0063] (18) "Suitability" is not limited to the case where the sound pressure is appropriate. "Suitability" may refer to whether the frequency characteristics are appropriate or not. "Suitability" may refer to whether the sound pressure of the speech voice is appropriate relative to the sound pressure of the noise. "Suitability" may also be a judgment result based on an index (STI: Speech Transmission Index) that evaluates the clarity of the voice. The original waveform of the voice becomes difficult to hear due to reverberation or noise during the transmission process. STI is an index that evaluates the clarity of the voice based on how faithfully the voice is transmitted without such waveform distortion. In this embodiment, a transfer function H1 from the speaker to the listener, a transfer function H2 from the speaker to the microphone 11a, a total gain G of the microphone 11a, the amplifier 12a, and the speaker 13a, and a transfer function H3 from the speaker 13a to the listening position are obtained by simulation or measurement. As described above, the transfer function including the loudspeaker system is expressed as H1+(H2+H3)*G. The transfer function can be expressed by an impulse response IR in the time domain. The LISTENING SOUND OBSERVATION DEVICE 200 measures noise N, such as air conditioning noise, in advance or during a time period when no speech is being made. The sound pressure sp5 at the listening position is calculated by the above formula (3) or (6). Therefore, the SN ratio of speech to noise is calculated by sp5 / N. The STI is calculated based on the impulse response IR and the SN ratio, in accordance with IEC60268-16. The LISTENING SOUND OBSERVATION DEVICE 200 may display a value according to the calculated STI instead of the sound pressure. For example, a standard for the STI is set such that 0.75 or more is Excellent, and 0.6 to 0.75 is Good. Therefore, the LISTENING SOUND OBSERVATION DEVICE 200 may display the numerical value of the STI, or may display Excellent or Good according to this standard.

[0064] (19) Fig. 14 is a schematic side view of a conference room. The sound acquisition device 200 of this example emits light according to the directional angle of the sound emitted by the sound emission means, and provides the speaker with the sound emission area as visual information by the light.

[0065] In the example of Figure 14, each speaker installed on the ceiling is provided with a light emitter that emits light according to the directional angle of the sound. The area where the sound from multiple speakers reaches is bright because the light from multiple light emitters hits it. Also, if there is a step in the ceiling or a partition in the space, the light from the light emitter will be blocked.

[0066] Because light and sound have different diffraction conditions and attenuation rates, the ranges where light and sound can easily reach and the ranges where they cannot easily reach are not exactly the same. However, as a general trend, it can be interpreted that locations where light can easily reach are also locations where sound can easily reach. Therefore, speakers can visually and intuitively understand that loud sounds can reach bright places and sound cannot easily reach dark places. [Explanation of symbols]

[0067] 100: Public address system, 10: Public address transmission path, 11: Sound collection means, 12: Amplification means, 13: Sound emission means, 11a: Microphone, 12a: Amplifier, 13a: Speaker, 20: Direct transmission circuit, 200: Hearing sound acquisition device, 201: Control unit, 202: Measurement unit, 203: Information provision unit, M i ,M j ...Conference participants

Claims

1. A method for acquiring a sound pressure at a listening position of a listener in a public address system that delivers a speech sound of a speaker to a listener through a public address transmission path including a sound collection means, an amplification means, and a sound emission means, comprising: the speech sound reaches the listener via a direct transmission path that does not include the loudspeaker transmission path; The method for acquiring a heard sound includes acquiring a sound pressure at an arbitrary position on a transmission path of the speech sound, and calculating a sound pressure at a listening position of the listener based on the acquired sound pressure. How to obtain audible sounds.

2. measuring a sound pressure at an arbitrary position on a transmission path of the speech sound, and calculating the sound pressure at the listening position of the listener by a calculation based on the measured sound pressure; The method for acquiring audible sounds according to claim 1 .

3. 2. The method for acquiring sound as claimed in claim 1, further comprising the steps of: measuring a sound pressure of the input sound to the sound collecting means; and determining the sound pressure at the listening position by a calculation based on the measured sound pressure.

4. The method for acquiring sound as claimed in claim 1 , further comprising the steps of: measuring a sound pressure of the output sound of the sound emitting means; and determining the sound pressure at the listening position by a calculation based on the measured sound pressure.

5. 2. The method for acquiring sound as claimed in claim 1, further comprising measuring a sound pressure of the input sound to the sound collection means and a sound pressure of the output sound from the sound emission means, and determining the sound pressure at the listening position by a calculation based on the measured sound pressures.

6. The method for acquiring heard sounds according to claim 1 , further comprising the steps of measuring a sound pressure of the speech sound, and determining the sound pressure at the listening position by a calculation based on the measured sound pressure.

7. The method for acquiring a sound to be heard according to claim 1 , further comprising the steps of: determining a relationship of the sound pressure of the uttered sound to an appropriate value; and providing the speaker with visual information indicating a result of the determination.

8. The method for acquiring audible sounds according to claim 1 , further comprising the steps of: determining a relationship of the sound pressure of the uttered sound to an appropriate value; and providing the speaker with sensory information indicating the determination result.

9. The method for acquiring a heard sound according to claim 7 , further comprising determining a relationship of the sound pressure of the speech sound to an appropriate value based on the sound pressure at the listening position.

10. The method for acquiring sound according to claim 7 , wherein the device for providing the visual information is arranged in correspondence with the sound emitting means.

11. The method for acquiring heard sounds according to claim 1 , wherein the sound pressure at the listening position is provided to the speaker as a sound pressure distribution.

12. The method for acquiring audible sounds according to claim 1 , further comprising emitting light according to a directional angle of the sound emitted by the sound emitting means, and providing the speaker with a sound emission area of ​​the sound as visible information by the light.

13. The method for acquiring audible sounds according to claim 1, further comprising arranging indices at multiple locations that change in proportion to the magnitude of the sound pressure, thereby providing the speaker with visual information indicating the relationship of the sound pressure of the speech sound to an appropriate value.

14. Detecting head positions of the talker and the listener participants; obtaining a transfer function from the speaker to the position of the listener via the direct transfer path, a transfer function from the speaker to the sound collection means, and a transfer function from the sound amplification means to the position of the listener, based on the position of the listener's head; determining a sound pressure at the listening position of the listener based on the acquired transfer functions; The method for acquiring audible sounds according to claim 1 .

15. A sound acquisition device for acquiring a sound pressure at a listening position of a listener in a public address system that delivers a speech sound of a speaker to a listener through a public address transmission path including a sound collection means, an amplification means, and a sound emission means, comprising: the speech sound reaches the listener via a direct transmission path that does not include the loudspeaker transmission path; The heard sound acquisition device includes a control unit that acquires a sound pressure at an arbitrary position on a transmission path of the speech sound and calculates a sound pressure at the listening position of the listener based on the acquired sound pressure. Audible sound acquisition device.

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