Sound output method and sound output device

Abstract

To provide a sound output method and a sound output device of a directional speaker capable of appropriately providing sound to a user even when the position of the user's head changes in the height direction.SOLUTION: In a phone booth 1, in a sound output method, multiple directional speakers 3A to 3C are arranged in the height direction and detection processing to detect the position of the user's head is performed, a specification process is performed to specify the directional speaker placed at the height of the detected user's head position, and control is performed to make the volume of the directional speaker specified in the specification process louder than other directional speakers.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] One embodiment of the present invention relates to a sound output method and a sound output device for a directional speaker.

Background Art

[0002] Patent Document 1 discloses a configuration that makes it difficult for a listener in front of a certain electrostatic speaker among electrostatic speakers arranged in a horizontal row to hear the sound emitted from the adjacent electrostatic speaker.

Prior Art Document

Patent Document

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[0007] According to one embodiment of the present invention, sound can be appropriately provided to the user even when the position of the user's head changes in the vertical direction. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing phone booth 1. [Figure 2] This is a plan view of the interior of phone booth 1. [Figure 3] This is an elevation view of the interior of phone booth 1. [Figure 4] This is an elevation view of the interior of phone booth 1. [Figure 5] This is a block diagram showing the hardware configuration of the sound output device 5. [Figure 6] This is a flowchart showing the operation of the sound output device 5. [Figure 7] This is a plan view of the interior of phone booth 1A according to Modification 1. [Figure 8] This is an elevation view of the interior of phone booth 1A. [Figure 9] This is a block diagram showing the hardware configuration of the sound output device 5A according to modified example 1. [Figure 10] This is an elevation view of the interior of phone booth 1B according to Modification 2. [Figure 11] This is an elevation view of the interior of phone booth 1C according to Modification 3. [Figure 12] This is an elevation view of the interior of phone booth 1D according to Modification 4. [Figure 13] This is a front view of panel 10D according to modified example 5. [Figure 14] This is a front view of panel 10D according to modified example 7. [Figure 15] This is a plan view of the interior of phone booth 1E according to modified example 8. [Figure 16] This is a plan view of the interior of the phone booth 1F according to the modified example 9. [Figure 17] It is an elevation view of the interior of the phone booth 1G of Modification Example 10, seen in elevation. [Figure 18] It is a perspective view of the frame system 100.

Mode for Carrying Out the Invention

[0009] FIG. 1 is a perspective view showing the phone booth 1 of the present embodiment. FIG. 2 is a plan view of the interior of the phone booth 1, seen in plan. FIGS. 3 and 4 are elevation views of the interior of the phone booth 1, seen in elevation.

[0010] The phone booth 1 is assembled from a plurality of panels. The phone booth 1 of the present embodiment consists of five panels 10A, panel 10B, panel 10C, and panel 10D.

[0011] Panel 10A is disposed at the front of the phone booth 1. Panels 10B and 10C are disposed on the left and right sides of the phone booth 1. Panel 10D is disposed at the back of the phone booth 1. The phone booth 1 of the present embodiment has no panel on the ceiling surface and is open. However, the phone booth 1 may have a panel on the ceiling surface or a panel on the floor surface. Note that a phone booth means a simple soundproof room, and may be an individual room that is a space closed by a plurality of panels, or may be a semi-individual room with a part open.

[0012] Panels 10A, 10B, 10C, and 10D are each in the shape of a thin plate. Panels 10A, 10B, 10C, and 10D have a rectangular wall surface that is long in the vertical direction. Panels 10A, 10B, 10C, and 10D are connected to each other at the long side portions of the wall surfaces. Thereby, the phone booth 1, which is a simple soundproof room, is formed.

[0013] Panel 10A includes a door 13. The user of the phone booth 1 opens and closes the door 13 and enters and exits the interior of the phone booth 1.

[0014] Panel 10D comprises a plurality of planar speakers 3A, 3B, and 3C. Planar speakers 3A, 3B, and 3C are each examples of directional speakers according to the present invention.

[0015] In this example, planar speakers 3A, 3B, and 3C are each rectangular in shape, longer in the width direction and shorter in the height direction when viewed from the front. However, planar speakers 3A, 3B, and 3C can each have any shape. For example, planar speakers 3A, 3B, and 3C may each be square, or rectangular in shape, longer in the height direction and shorter in the width direction.

[0016] Planar speakers 3A, 3B, and 3C are arranged in a vertical line on the inner wall surface of the phone booth 1 within panel 10A.

[0017] Planar speakers 3A, 3B, and 3C are each oriented toward the portion of the wall on which they are installed (the wall surface of panel 10A). In other words, the sound emission direction of planar speakers 3A, 3B, and 3C is directed toward the interior of the phone booth 1.

[0018] In this example, panel 10D is equipped with a foldable table 4. Users may use the phone booth 1 while standing inside, as shown in Figure 3, or they may use the phone booth 1 while sitting inside, with the table 4 extended, as shown in Figure 4. The sound output device of this embodiment can appropriately provide sound to the user even when the position of the user's head changes in the height direction.

[0019] Figure 5 is a block diagram showing the hardware configuration of the sound output device 5 of this embodiment. Figure 6 is a flowchart showing the operation of the sound output device 5. The sound output device 5 comprises an input unit 301, a signal processing unit 302, amplifiers 303A, 303B, 303C, a camera 90, a control unit 91, a planar speaker 3A, a planar speaker 3B, and a planar speaker 3C.

[0020] The input unit 301 is equipped with an analog audio interface, a digital audio interface, or a communication interface such as USB. The input unit 301 receives audio signals from devices that output audio signals (for example, audio equipment that outputs masking sounds, audio equipment that outputs content sounds, or information processing devices, etc.). The signal processing unit 302 performs signal processing on the audio signals received by the input unit 301. For example, the signal processing unit 302 performs level control or frequency characteristics adjustment of the audio signals. Note that when the input unit 301 receives an analog audio signal, the signal processing unit 302 converts it to a digital audio signal before performing signal processing. The signal processing unit 302 converts the processed audio signal back to an analog audio signal and outputs it to amplifiers 303A, 303B, and 303C.

[0021] Amplifiers 303A, 303B, and 303C each amplify the sound signal after it has been processed by the signal processing unit 302. Amplifiers 303A, 303B, and 303C each output the amplified sound signal to planar speakers 3A, 3B, and 3C, respectively. Planar speakers 3A, 3B, and 3C each output sound based on the sound signal amplified by amplifiers 303A, 303B, and 303C. The sound output device 5 outputs sound received from, for example, an information processing device via planar speakers 3A, 3B, and 3C. The information processing device is connected to another information processing device in a remote location, for example, via a network. The information processing device connected to the sound output device 5 receives sound signals from the remote location via the network. As a result, the sound output device 5 outputs the voice of a user in the remote location.

[0022] Alternatively, the sound output device 5 may output content sound. The sound output device 5 may also output masking sound. Masking sound is a sound that prevents a third party (in this example, the user inside the phone booth 1) from understanding the content of the conversation. Preferably, the masking sound includes a disruption sound that disrupts speech, a continuously occurring background sound, and an intermittently occurring performance sound. Disruption sound is, for example, a sound obtained by altering a person's voice on the time axis or frequency axis so that it has no lexical meaning (the content is incomprehensible). Disruption sound has the quality of a human voice, but it cannot be recognized as conversational speech emitted by a person. Therefore, disruption sound may cause discomfort to the listener, and listening to it for a long time or at an excessive volume may cause unpleasantness. For this reason, it is preferable to combine the disruption sound with background sound and performance sound. Background sound is, for example, the babbling of a stream or the rustling of trees, a sound that is unlikely to attract the attention of a third party and does not cause unpleasantness. This allows background noise to increase the ambient noise level, making disruptive sounds less noticeable and thus reducing the sense of discomfort caused by disruptive sounds. Furthermore, the special effects sounds are highly dramatic sounds such as intermittently occurring musical tones. This directs the attention of third parties to the special effects sounds, making the sense of disruptive sounds less noticeable from an auditory psychological perspective.

[0023] If conversation sounds from outside the phone booth 1 enter the phone booth 1, it may disrupt the concentration of the person using the phone booth 1. By outputting the masking sound described above, the sound output device 5 can reduce the perceived noise of conversation sounds entering the phone booth 1 from outside, thereby improving the concentration of the person inside the phone booth 1.

[0024] Planar speakers 3A, 3B, and 3C are each thin, flat speakers. Planar speakers 3A, 3B, and 3C are each, for example, electrostatic speakers. Electrostatic speakers have a structure in which a sheet-like diaphragm is sandwiched between two fixed electrodes. Electrostatic speakers generate electrostatic force by applying voltage to the fixed electrodes and the diaphragm. Electrostatic speakers change the electrostatic force by changing the voltage applied to the fixed electrodes. The diaphragm vibrates due to the change in electrostatic force. As a result, planar speakers 3A, 3B, and 3C each output planar sound waves. Planar speakers 3A, 3B, and 3C each output sound with strong directivity in the forward direction (normal direction to the main surface).

[0025] As a result, the sound emitted by planar speakers 3A, 3B, and 3C reaches the wall surface of the opposing panel 10A without spreading widely. Therefore, the sound emitted by planar speakers 3A, 3B, and 3C is less likely to leak outside the phone booth 1, which is a simple soundproof room.

[0026] The control unit 91 controls the power on / off of amplifiers 303A, 303B, and 303C. More specifically, the control unit 91 performs a detection process to detect the position of the user's head based on the image captured by the camera 90, and then performs a identification process to identify the planar speaker among planar speakers 3A, 3B, and 3C that is positioned at the height of the detected user's head. The control unit 91 then turns on the amplifier of the planar speaker identified in the identification process and turns off the amplifiers of the other planar speakers, thereby controlling the volume of the identified planar speaker to be louder than that of the other planar speakers.

[0027] Camera 90 is installed on panel 10D. Camera 90 is installed to capture the entire interior of phone booth 1. The control unit 91 performs image recognition processing on the image captured by camera 90 to detect the presence or absence of a person inside phone booth 1 and the position of their head (S11). For example, the control unit 91 divides the image captured by camera 90 into three parts in the height direction. For example, the control unit 91 divides it into a first region with the highest field of view in the height direction, a second region with the second highest field of view, and a third region with the lowest field of view. The control unit 91 determines which region the user's head, recognized by the image recognition processing, belongs to. For example, in the situation shown in Figure 3, the control unit 91 determines that the user's head belongs to the second region, and in the situation shown in Figure 4, the control unit 91 determines that the user's head belongs to the third region. Alternatively, for example, if the user is tall, the control unit 91 may determine that the user's head belongs to the first region.

[0028] Next, the control unit 91 identifies a planar speaker positioned at the height of the detected user's head (S12). The control unit 91 identifies the planar speaker based on the region to which the user's head belongs, as recognized by the image recognition process. For example, in the situation shown in Figure 3, the control unit 91 identifies planar speaker 3B because the user's head belongs to the second region. In the situation shown in Figure 4, the control unit 91 identifies planar speaker 3C because the user's head belongs to the third region.

[0029] The control unit 91 controls the volume of the identified planar speaker to be louder than the other planar speakers by turning on the amplifier of the identified planar speaker and turning off the amplifiers of the other planar speakers (S13). For example, in the situation shown in Figure 3, the control unit 91 has identified planar speaker 3B, so it turns on amplifier 303B and turns off amplifiers 303A and 303C. Also, in the situation shown in Figure 4, the control unit 91 has identified planar speaker 3C, so it turns on amplifier 303C and turns off amplifiers 303A and 303B.

[0030] The control unit 91 may also turn on all amplifiers 303A, 303B, and 303C and control the level of the specified planar speaker to be higher than the levels of the other planar speakers. In particular, it is preferable for the control unit 91 to reduce the volume of planar speakers installed in positions where sound leakage is likely to occur. For example, the phone booth 1 has no ceiling and is open. Therefore, sound from planar speaker 3A is particularly likely to leak to the outside. Accordingly, the control unit 91 reduces the volume of planar speaker 3A, which is located at the highest position in the height direction.

[0031] Furthermore, the control unit 91 may control the volume of each frequency of the sound signal supplied to amplifiers 303A, 303B, and 303C, respectively. For example, if the control unit 91 identifies planar speaker 3B, it may control the signal processing unit 302 to allow the sound signal supplied to planar speaker 3B to pass through the entire frequency range, while cutting out low-frequency sound signals (e.g., below 800Hz) from the sound signal supplied to planar speaker 3A. In this way, the control unit 91 may cut out low-frequency sounds that are prone to leakage from planar speakers installed in locations where sound leakage is likely.

[0032] Furthermore, the control unit 91 may control the signal processing unit 302 to supply a first sound signal to a specified planar speaker and a second sound signal to other planar speakers as different types of sounds. For example, if the control unit 91 identifies planar speaker 3B, it may control the signal processing unit 302 to supply a sound signal of a voice from a remote location to planar speaker 3B and a sound signal of a masking sound to planar speaker 3A.

[0033] As described above, the sound output device 5 can provide sound appropriately to the user even when the user's head position changes in the height direction. The phone booth, which is a simple soundproof room, needs to be able to hear emergency broadcasts at a predetermined volume according to the instructions of the fire department. Therefore, the phone booth must allow a certain amount of sound to enter. In addition, the phone booth 1 of this embodiment has no ceiling and is open, so sound leakage is particularly easy in the height direction.

[0034] Furthermore, the planar speakers 3A, 3B, and 3C of this embodiment output the voice of a user in a remote location, as an example. As described above, since the planar speakers 3A, 3B, and 3C each output sound with strong directivity in the forward direction (normal direction of the main surface), it is difficult for the sound to leak outside the phone booth 1. However, if the voice of a user in a remote location is output at a high level from all of the planar speakers 3A, 3B, and 3C, the volume of sound leaking outside the phone booth 1 will also increase.

[0035] In contrast, the sound output device 5 of this embodiment controls the volume of the planar speaker positioned at the user's head height to be louder than the other planar speakers among planar speakers 3A, 3B, and 3C. As a result, users of the phone booth 1 can hear the sound output from the planar speakers more easily, regardless of whether they are standing or sitting in the phone booth, or their height, providing a new customer experience. Furthermore, the sound output device 5 of this embodiment can reduce sound leakage outside the phone booth 1.

[0036] In the example above, planar speakers 3A, 3B, and 3C are installed on panel 10D, but they may be installed on panel 10A, panel 10B, or panel 10C.

[0037] (Variation 1) Next, Figure 7 is a plan view of the interior of the phone booth 1A according to Modification 1. Components common to Figure 2 are given the same reference numerals and their descriptions are omitted. Figure 8 is an elevation view of the interior of the phone booth 1A. Components common to Figure 3 are given the same reference numerals and their descriptions are omitted. Figure 9 is a block diagram showing the hardware configuration of the sound output device 5A according to Modification 1. Components common to Figure 5 are given the same reference numerals and their descriptions are omitted.

[0038] The phone booth 1A according to Modification 1 is equipped with multiple microphones 9A, 9B, and 9C arranged in the height direction, instead of a camera 90. In the above embodiment, the control unit 91 detected the position of the user's head based on an image captured by the camera 90, but the sound output device 5A of Modification 1 detects the position of the user's head based on sound signals acquired by the multiple microphones 9A, 9B, and 9C.

[0039] The control unit 91 of the sound output device 5A estimates the direction of the sound source by calculating the cross-correlation of sound signals acquired by multiple microphones 9A, 9B, and 9C, for example. In this case, the sound source is the user's head (mouth) inside the phone booth 1A. By determining the peak of the cross-correlation, the control unit 91 can determine the time difference in which the sound from the sound source reaches the multiple microphones 9A, 9B, and 9C. Based on this time difference, the control unit 91 can detect the height position of the user's head.

[0040] The method for detecting the position of a person's head inside the phone booth is not limited to methods based on images captured by camera 90.

[0041] (Modification 2) Figure 10 is an elevation view of the interior of phone booth 1B according to modified example 2. Components common to Figure 3 are denoted by the same reference numerals and their descriptions are omitted.

[0042] The sound emission direction of the planar speaker 3A in phone booth 1B is directed diagonally downwards. Because phone booth 1B has no ceiling and is open, sound leakage is particularly easy in the vertical direction. However, in modification 2, the sound emission direction of the planar speaker 3A is directed diagonally downwards, so sound leakage outside phone booth 1B is reduced.

[0043] The planar speaker 3A may also be attached to the panel 10A via a mechanism that mechanically adjusts the tilt angle. In this case, the adjustment mechanism may be configured so that when the planar speaker 3A is not outputting sound, the sound emission direction of the planar speaker 3A is horizontal, and when the planar speaker 3A is outputting sound, the sound emission direction of the planar speaker 3A is angled downwards.

[0044] (Variation 3) Figure 11 is an elevation view of the interior of phone booth 1C according to Modification 3. Phone booth 1C of Modification 3 has the same configuration as phone booth 1 shown in Figure 3.

[0045] In the modification 3, the control unit 91 identifies multiple planar speakers during the identification process in S12. For example, as shown in Figure 11, if there is a first user standing in the phone booth 1C and a second user sitting in the phone booth 1C, the control unit 91 detects the position of the users' heads in multiple regions (a second region corresponding to planar speaker 3B and a third region corresponding to planar speaker 3C). Therefore, the control unit 91 identifies planar speaker 3B and planar speaker 3C.

[0046] In this case, the control unit 91 turns on amplifiers 303B and 303C and turns off amplifier 303A. Therefore, sound is output from planar speaker 3B and planar speaker 3B.

[0047] This allows the control unit 91 to appropriately provide sound to multiple users inside the phone booth 1C.

[0048] The control unit 91 may, instead of turning off the amplifiers of other planar speakers (amplifier 303A in the above example), turn on all amplifiers 303A, 303B, and 303C to control the level of the specified multiple planar speakers to be higher than the levels of the other planar speakers. Alternatively, the control unit 91 may set the volume of the first planar speaker to be higher than the volume of the second planar speaker among the specified multiple planar speakers. For example, in the example of Figure 11, planar speaker 3C is installed at the lowest position and is the least likely to leak sound, so the volume of planar speaker 3C may be set to be higher than the volume of planar speaker 3B. Or, in the example of Figure 11, planar speaker 3B is far from the first user and planar speaker 3C is close to the second user, so the volume of planar speaker 3A may be increased and the volume of planar speaker 3C may be decreased.

[0049] (Modification 4) Figure 12 is an elevation view of the interior of phone booth 1D according to Modification 4. Phone booth 1D of Modification 4 has the same configuration as phone booth 1B shown in Figure 10.

[0050] In Modification 4, the only user of the phone booth 1D is the first user standing inside the phone booth 1D, but the control unit 91 identifies multiple planar speakers in the identification process of S12. For example, the control unit 91 further identifies planar speakers corresponding to areas close to the user's head position. In the example of Figure 12, the control unit 91 identifies planar speakers 3A and 3B. Planar speaker 3A is less prone to sound leakage because its sound emission direction is angled downwards. Therefore, in addition to the planar speaker corresponding to the user's head position, the control unit 91 may also identify planar speaker 3A, which is even less prone to sound leakage. This allows the control unit 91 to widen the sound delivery area while preventing sound leakage.

[0051] Furthermore, the planar speaker 3C is installed at the lowest position and is least likely to leak sound. Therefore, the control unit 91 may identify a planar speaker 3C that leaks less sound than the planar speaker 3B, in addition to the planar speaker 3B that corresponds to the position of the user's head.

[0052] Furthermore, the control unit 91 may control the signal processing unit 302 to apply a delay to at least one of the sound signals supplied to each of the specified planar speakers. For example, in the example shown in Figure 12, planar speaker 3B is positioned closer to the user's head than planar speaker 3A. Therefore, the control unit 91 may control the signal processing unit 302 to apply a delay to the sound signal supplied to planar speaker 3B. The control unit 91 ensures that the sound output from planar speakers 3A and 3B reaches the user at the same time. As a result, the user is less likely to perceive a phase difference in sound due to the time difference, and can hear natural sound without feeling any discomfort. In other words, the user can obtain a new customer experience.

[0053] Furthermore, users perceive the localization of sound sources based on differences in volume, time, and frequency characteristics among multiple planar speakers. In contrast, the control unit 91 ensures that the sound output from planar speakers 3A and 3B reaches the user at the same time. Because users have difficulty perceiving localization due to time differences, they often rely on their vision to perceive localization as being more directly in front of them. As a result, users can perceive the direction of sound coming from a distance as being directly in front of them, providing a new customer experience.

[0054] (Variation 5) Figure 13 is a front view of panel 10D according to Modification 5. In this example, panel 10D includes planar speakers 3A1, 3A2, 3B1, 3B2, 3C1, and 3C2.

[0055] Planar speakers 3A1 and 3A2 are arranged side by side. Planar speakers 3B1 and 3B2 are arranged side by side. Planar speakers 3C1 and 3C2 are arranged side by side. In other words, the multiple planar speakers 3A, 3B, and 3C, which are arranged in the height direction, are each further divided into multiple planar speakers arranged to the left and right.

[0056] The control unit 91 performs identification processing to identify the planar speakers positioned at the height of the detected user's head, as described above. For example, when the control unit 91 detects a head at the height of planar speaker 3B as shown in Figure 3, it identifies planar speakers 3B1 and 3B2.

[0057] In this case, the control unit 91 may control the signal processing unit 302 to supply audio signals of different channels to the multiple planar speakers divided into left and right sections. For example, the control unit 91 may control the signal processing unit 302 to supply the L-channel audio signal to the planar speaker 3B1 and the R-channel audio signal to the planar speaker 3B1. This allows the control unit 91 to perform stereo playback.

[0058] Furthermore, the control unit 91 may control the signal processing unit 302 to supply the same channel of sound signal to multiple planar speakers divided into left and right sections. In this case, the control unit 91 may control the signal processing unit 302 to apply a delay to at least one of the sound signals supplied to each of the left and right planar speakers. For example, the control unit 91 may control the signal processing unit 302 to apply a delay to the sound signal supplied to the planar speaker positioned close to the user's head. This makes it less likely for the user to perceive a phase shift in sound due to the time difference, allowing them to hear natural sound without feeling any discomfort. In addition, the user will be less likely to perceive localization due to the time difference, and will be able to perceive the direction of arrival of distant sounds as being directly in front of them. In other words, the user can obtain a new customer experience.

[0059] (Experimental variation 6) In the modified example 6, the control unit 91 applies an inverse transfer function correction process to at least one of the sound signals supplied to each of the specified planar speakers in the modified example 4 or 5.

[0060] The transfer function represents the frequency characteristics of the acoustic path from the planar speaker to the user. The transfer function can be determined, for example, by pre-installing a microphone at the user's head position, outputting test sounds from multiple planar speakers, and acquiring the impulse response of each. The control unit 91 controls the signal processing unit 302 to apply an inverse correction process of the transfer function to the sound signal supplied to the identified planar speaker.

[0061] As described above, users perceive the localization of sound sources based on differences in volume, time, and frequency characteristics among multiple planar speakers. In response, the control unit 91 controls the signal processing unit 302 to perform inverse correction processing of the transfer function. The signal processing unit 302 convolves the inverse function of the transfer function instructed by the control unit 91 into the sound signal supplied to the planar speakers.

[0062] This allows the control unit 91 to eliminate differences in the frequency characteristics of multiple planar speakers. Because users are less likely to perceive localization due to differences in frequency characteristics, they often rely on their vision to perceive localization as being more directly in front of them. As a result, users can perceive the direction of sound coming from a distance as being directly in front of them, providing a new customer experience.

[0063] (Example 7) Figure 14 is a front view of panel 10D according to Modification 7. In this example, the multiple planar speakers are arranged in an array. In this example, the multiple planar speakers 3A, 3B, and 3C, which are arranged in the height direction, are each further divided into n planar speakers (where n is any integer greater than or equal to 3) to the left and right. For example, planar speaker 3A is divided from planar speaker 3A1 to planar speaker 3An. Planar speaker 3B is divided from planar speaker 3B1 to planar speaker 3Bn. Planar speaker 3C is divided from planar speaker 3C1 to planar speaker 3Cn.

[0064] In this case, the sound output from the divided planar speakers forms a composite wavefront in the forward direction. Therefore, planar speakers 3A, 3B, and 3C each output sound with even stronger directivity in the forward direction. Consequently, according to the configuration of Modified Example 7, sound leakage outside the phone booth is further reduced.

[0065] The control unit 91 may also control the signal processing unit 302 to control the timing of supplying sound signals to each of the multiple directional speakers arranged in an array. This allows the control unit 91 to control the combined wavefront of the sound output from the divided planar speakers and control its directivity. As a result, the control unit 91 can, for example, set the focal point of the combined wavefront at the user's head, and ensure that the sound output from the planar speakers reaches only the user's head.

[0066] (Variation 8) Figure 15 is a plan view of the interior of phone booth 1E according to Modification 8. Panel 10D of Modification 8 has a planar speaker 3D positioned outside phone booth 1E. The other configurations are the same as phone booth 1.

[0067] The planar speaker 3D, positioned outside the phone booth 1E, can mask sounds leaking from inside the phone booth 1E to the outside by outputting a masking sound. This makes it difficult for people outside the phone booth 1E to hear the voice of the user inside the phone booth 1E, the content sound that the user is listening to, or the voice of a user in a remote location. In this way, the control unit 91 may supply the first sound signal to the planar speaker inside the phone booth and the second sound signal to the external planar speaker as different types of sounds.

[0068] (Extreme variation 9) Figure 16 is a plan view of the interior of phone booth 1F according to Modification 9. In phone booth 1F of Modification 8, multiple planar speakers are arranged on the wall surfaces of multiple panels. For example, panel 10B has a planar speaker 3E and multiple planar speakers (not shown) arranged in the height direction of the planar speaker 3E. Panel 10C has a planar speaker 3F and multiple planar speakers (not shown) arranged in the height direction of the planar speaker 3F. Panel 10A has a planar speaker 3G and multiple planar speakers (not shown) arranged in the height direction of the planar speaker 3G.

[0069] Thus, multiple planar speakers are not limited to being arranged on a single panel, but may be arranged on multiple panels.

[0070] (Variation 10) The control unit 91 in the modified example 10 detects the positional relationship between the first user, the second user, and the multiple planar speakers, and controls the volume of the multiple planar speakers based on this positional relationship.

[0071] Figure 17 is an elevation view of the interior of phone booth 1G in the modified example 10. In this example, panel 10A comprises a plurality of planar speakers 3G, 3H, and 3I arranged in the height direction. The sound emission direction of planar speakers 3A and 3G, which are located at the highest position in the height direction, is directed diagonally downward.

[0072] The control unit 91 identifies multiple planar speakers. For example, as shown in Figure 17, if there is a first user standing in phone booth 1C and a second user sitting in phone booth 1C, the control unit 91 identifies planar speakers 3B and 3H corresponding to the head position of the first user. The control unit 91 also identifies planar speakers 3C and 3I corresponding to the head position of the second user.

[0073] Furthermore, the control unit 91 detects, in the example shown in Figure 17, that the first user is located between the planar speaker 3I and the second user, based on the positional relationship between the first user, the second user, and the multiple planar speakers. Because the first user is located between the planar speaker 3I and the second user, the sound output by the planar speaker 3I is unlikely to reach the second user. Therefore, based on this positional relationship, the control unit 91 sets the planar speaker 3I to not output sound. In addition, the control unit 91 outputs sound for the second user from the planar speaker 3A. As a result, the control unit 91 can prevent the output of unnecessary sounds that cannot be effectively delivered to the users, thereby enhancing the sound leakage prevention effect, and can also appropriately deliver sound to all of the multiple users.

[0074] (Variation 11) The above examples all show cases where multiple planar speakers are mounted on the wall of a phone booth. However, the present invention is not limited to use in phone booths.

[0075] Figure 18 is a perspective view of the frame system 100. The frame system 100 in Figure 18 comprises four columns 20A, 20B, 20C, and 20D and four beams 25A, 25B, 25C, and 25D.

[0076] Columns 20A, 20B, 20C, and 20D are positioned at the four corners of the frame system 100 and are elongated rectangular prisms in the height direction. Beams 25A, 25B, 25C, and 25D are elongated rectangular prisms in the plane direction. Beams 25A, 25B, 25C, and 25D connect the four columns 20A, 20B, 20C, and 20D at their upper ends in the height direction.

[0077] Beams 25A, 25B, 25C, and 25D can each be used to suspend any equipment, such as lighting fixtures. In the example shown in Figure 18, beam 25A suspends a board 75. Multiple planar speakers 3A, 3B, and 3C are attached to the board 75.

[0078] Thus, the use of multiple planar speakers is not limited to being mounted on the wall of a phone booth.

[0079] In this embodiment, an electrostatic planar speaker is shown as an example of a directional speaker. However, the planar speaker may also be, for example, a dynamic planar speaker. Furthermore, the directional speaker may be an array speaker formed by arranging multiple dynamic speakers.

[0080] Planar speakers may be embedded in the wall surface of the panel. Furthermore, multiple planar speakers may be positioned at different heights, but they do not necessarily need to be at the same position horizontally.

[0081] The description of these embodiments should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, rather than by the embodiments described above. Furthermore, the scope of the invention is intended to include all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0082] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G: Phone booths 3A, 3B, 3C: Planar speaker 4: Table 5.5A: Sound output device 9A, 9B, 9C: Microphone 10A, 10B, 10C, 10D: Panel 13: Door 301: Input section 302: Signal Processing Unit 303A, 303B, 303C: Amplifier 20A,20B,20C,20D:Column 25A, 25B, 25C, 25D: Beam 75: Board 90: Camera 91: Control Unit 100: Frame System

Claims

1. Multiple directional speakers are arranged vertically and placed in a phone booth with an open ceiling. The system performs a detection process to detect the position of the user's head. A process is performed to identify the directional speaker among the plurality of directional speakers that is positioned at the height of the detected user's head. The control is performed to make the volume of the directional speaker identified in the aforementioned specific processing louder than that of the other directional speakers. Sound output method.

2. The control includes controlling the volume for each frequency. The sound output method according to claim 1.

3. The aforementioned identification process includes a process for identifying multiple directional speakers. The sound output method according to claim 1 or claim 2.

4. The control involves making the volume of the first directional speaker greater than the volume of the second directional speaker among the identified plurality of directional speakers. The sound output method according to claim 3.

5. The control involves applying a delay process to at least one of the sound signals supplied to each of the specified plurality of directional speakers. The sound output method according to claim 3 or claim 4.

6. The control involves applying an inverse transfer function correction process to at least one of the sound signals supplied to each of the specified plurality of directional speakers. The sound output method according to any one of claims 3 to 5.

7. The volume of the directional speaker located at the highest position in the vertical direction among the multiple directional speakers identified in the aforementioned specific processing is reduced. The sound output method according to any one of claims 2 to 6.

8. The first sound signal to be supplied to the directional speaker identified in the aforementioned specific processing, and the second sound signal to be supplied to the other directional speaker, are supplied as different types of sounds. The sound output method according to any one of claims 1 to 7.

9. The plurality of directional speakers are arranged in an array. The sound output method according to any one of claims 1 to 8.

10. Controlling the timing of supplying sound signals to each of the multiple directional speakers arranged in the array, The sound output method according to claim 9.

11. The aforementioned detection process is: The system detects the first user and the second user, The positional relationship between the first user, the second user, and the plurality of directional speakers is detected, The control controls the volume of the plurality of directional speakers based on the positional relationship. The sound output method according to any one of claims 1 to 10.

12. The plurality of directional speakers are mounted on the wall of the phone booth. The sound output method according to any one of claims 1 to 11.

13. The phone booth includes a plurality of the aforementioned wall surfaces, Each of the aforementioned multiple wall surfaces is fitted with one of the aforementioned multiple directional speakers. The sound output method according to claim 12.

14. A plurality of directional speakers arranged in a vertical line in a phone booth with an open ceiling, The system performs a detection process to detect the position of the user's head. A process is performed to identify the directional speaker among the plurality of directional speakers that is positioned at the height of the detected user's head. The control is performed to make the volume of the directional speaker identified in the aforementioned specific processing louder than that of the other directional speakers. Control unit and A sound output device equipped with [specific features / equipment].

15. The control includes controlling the volume for each frequency. The sound output device according to claim 14.

16. The aforementioned identification process includes a process for identifying multiple directional speakers. The sound output device according to claim 14 or claim 15.

17. The control unit sets the volume of the first directional speaker to be greater than the volume of the second directional speaker among the specified plurality of directional speakers. The sound output device according to claim 16.

18. The control unit applies a delay process to at least one of the sound signals supplied to each of the specified plurality of directional speakers. The sound output device according to claim 16 or claim 17.

19. The control unit applies an inverse transfer function correction process to at least one of the sound signals supplied to each of the specified plurality of directional speakers. The sound output device according to any one of claims 16 to 18.

20. The control unit reduces the volume of the directional speaker located at the highest position in the height direction among the multiple directional speakers identified in the specific processing. The sound output device according to any one of claims 15 to 19.

21. The control unit supplies a first sound signal to the directional speaker identified in the specific processing and a second sound signal to the other directional speaker as different types of sounds. The sound output device according to any one of claims 14 to 20.

22. The plurality of directional speakers are arranged in an array. The sound output device according to any one of claims 14 to 21.

23. The control unit controls the timing of supplying sound signals to each of the plurality of directional speakers arranged in the array. The sound output device according to claim 22.

24. The aforementioned detection process is: The system detects the first user and the second user, The positional relationship between the first user, the second user, and the plurality of directional speakers is detected, The control unit controls the volume of the plurality of directional speakers based on the positional relationship. The sound output device according to any one of claims 14 to 23.

25. The aforementioned multiple directional speakers are mounted on the wall of the phone booth. The sound output device according to any one of claims 14 to 24.

26. The phone booth includes a plurality of the aforementioned wall surfaces, Each of the aforementioned multiple wall surfaces is fitted with one of the aforementioned multiple directional speakers. The sound output device according to claim 25.

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