JP2009010808A - Loudspeaker device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loudspeaker device provided with a microphone array and a speaker array which makes the location of an utterer coincide with the direction of hearing a manified voice by using a directional control function by the arrays. <P>SOLUTION: Four loudspeaker units 1A, 1B, 1C, 1D are connected in single file. A voice uttered by an utterer 200A is collected by the loudspeaker unit 1A at a left end. The loudspeaker unit 1A transfers this audio signal to the respective loudspeaker units 1B, 1C, 1D. Furthermore, a control unit 2 sends a delay pattern for making the virtual focal point of emission sound beams coincide with the utterer 200A with respect to the loudspeaker units 1B, 1C, 1D. The loudspeaker units 1B, 1C, 1D beam-control the utterance audio signal transferred from the loudspeaker unit 1A by using the delay pattern sent from the control unit 2 for emitting sound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a loudspeaker device that includes a microphone and a speaker and that loudspeaks and outputs a collected sound signal.

  An audio conference apparatus for performing an audio conference by connecting a remote conference room via a communication line or a network has been put into practical use (for example, Patent Document 1). For example, as shown in FIGS. 3 and 4, this type of audio conference apparatus includes a microphone array and a speaker array. While transmitting to a device (partner device), the device reproduces the voice (voice of the partner conference room) sent from the partner device with a speaker array.

JP 2004-343668 A

  As described above, the audio conference device is a device for performing a remote conference by connecting a plurality of devices via a communication line or a network. The sound collection function of the microphone array of the audio conference device or the speaker array It has been proposed to use this audio conference apparatus as a loudspeaker that amplifies voice in a conference room or the like by using a sound emission function.

  On the other hand, in the conventional general loudspeaker, the microphone and the speaker are usually installed in a place away from each other, and when the speaker speaks to the microphone, the voice is loudened from the speaker in a completely different place. The problem was that it felt uncomfortable for the audience.

  In addition, in order to perform loudspeaking in a large conference room, as shown in FIG. 12, a plurality of the above audio conference devices are connected with cables, and one or several conference attendees are connected to each audio conference device (speaking unit). When the voice conference system is configured so that the voices are associated with each other, the voices that are loudened from the loudspeaker unit installed in the front are emitted to each conference attendee. In this case, as shown in FIG. 12, when the voice of the speaker (conference attendee) 501 at one end is loudly output from the loudspeaker unit 500D at the other end, the direction of the virtual sound source of the amplified voice 512 522 and the actual direction 521 of the speaker 501 can be greatly opened, and there is a problem that a listener (conference attendee) 502 who listens to the loud sound 512 is visually uncomfortable.

  In the case of a conference room that is the same space, the uttered voice 511 of the speaker 501 can be heard a little by the listener 502. There is a problem in that the loud sound coming from different directions is heard from different directions, giving the listener 502 a sense of incongruity and reducing the intelligibility of the speech.

  According to the present invention, in a loudspeaker using a loudspeaker unit having a microphone array and a speaker array, the directivity control function by the array is used to match the position of the speaker and the direction in which the loudspeaker can be heard. For the purpose.

  According to the first aspect of the present invention, a sound collection unit that collects a target audio signal that is an audio signal to be emitted, a sound source position detection unit that detects a sound source position where the target audio signal is generated, and a sound emission A sound emitting unit capable of controlling the directivity of a sound signal to be emitted, which emits the target sound signal and controls the directivity in a direction in which the directivity is diffused from the sound source position detected by the sound source position detecting unit. And a sound part.

  According to the first aspect of the present invention, the target sound signal is emitted with directivity that diffuses from the sound source position where the target sound signal is generated. As a result, the sound source (for example, the speaker) and the direction in which the sound signal can be heard match, and the direction in which the speaker can be seen and the direction in which the sound can be directly heard and the expanded sound signal are There is no need to create a sense of incongruity when the directions of hearing are inconsistent.

  In the present invention, the sound emission directivity control of the target sound signal by the sound emission unit is a control for completely matching the sound source position, and the sound emission directivity of the target sound signal is not completely matched with the sound source position. In addition, any of the controls directed toward the direction closer to the sound source direction is included.

  According to a second aspect of the present invention, in the first aspect of the present invention, the sound emitting unit is configured by a plurality of sound emitting units, and the directivity of the target sound signal emitted by each sound emitting unit is set to be the sound source, respectively. It is characterized by being controlled in the direction of diffusion from the position.

  In the invention of claim 2, the sound emission part is divided into a plurality of sound emission units. As a result, the degree of freedom of installation of the sound emitting unit is increased, and a large-scale loudspeaker can be configured.

  According to a third aspect of the present invention, in the first and second aspects of the invention, the sound collection unit is configured to delay a microphone array formed by arranging a plurality of microphones and an audio signal collected by the plurality of microphones. A sound collection control unit that collects an audio signal with a sound collection characteristic having directivity in a specific direction by combining, and the directivity when the sound source position detection unit collects the target audio signal Means for determining that a sound source position exists in the direction of.

  According to the third aspect of the present invention, a microphone array is provided in the sound collection unit to form a sound collection beam to collect a target audio signal. If a microphone array is used, a plurality of sound collecting beams having directivities in different directions can be formed in parallel, and sound signals can be picked up from these directions. This eliminates the need to install a sound source and makes it easier to collect sound and detect the position of the sound source.

  According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the sound collecting unit includes a plurality of sound collecting units, and the sound source position detecting unit is directed to a direction of the sound collecting unit that picks up the target audio signal. Includes means for determining that a sound source position exists.

  In the invention of claim 4, the sound collecting unit is divided into a plurality of sound collecting units. As a result, the degree of freedom of installation of the sound collection unit is increased, and a large-scale loudspeaker can be configured. When the target voice signal is collected, a rough sound source position can be detected depending on which sound collection unit picks up the target voice signal. The sound output directivity may be controlled by this rough sound source position, and further, the sound source position may be detected in detail by the sound collecting beam of claim 3. Note that the sound collection unit may be integrated with the sound emission unit of claim 2 to constitute a loudspeaker unit.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the target sound is provided with directivity in a predetermined specific direction until the sound source position detection unit detects the sound source position. A feature is that a signal is emitted.

  According to the invention of claim 5, until the sound source position detecting unit detects the sound source position, the sound emitting unit emits the target sound signal with directivity in a predetermined specific direction. This prevents the target sound signal from being emitted when the sound source position detector takes time to detect the sound source position or when the sound source position detector cannot detect the sound source position. Can do. When the sound source position is detected, the sound emission directivity control of the target sound signal may be switched from the specific direction to the detected sound source position.

  According to the present invention, since the sound output directivity of the target audio signal can be controlled in the direction of the sound source position, it is possible to make the listener listen to the expanded audio signal without a sense of incongruity.

An audio conference apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 and FIG. 2 are diagrams for explaining the schematic configuration of the loudspeaker of this embodiment. 4-5 is a figure explaining the structure of the loudspeaker unit which comprises a loudspeaker. 6 to 11 are diagrams illustrating configuration examples when a loudspeaker is configured by connecting a plurality of loudspeaker units.

≪Explanation of schematic structure≫
First, the schematic configuration of the loudspeaker will be described with reference to FIGS.
FIG. 1A is a diagram for explaining a sound collection method in the loudspeaker of this embodiment, and FIG. 1B is a diagram for explaining a sound emission method in the loudspeaker. 2A is a schematic block diagram of a signal processing unit of the loudspeaker, and FIG. 2B is a block diagram of a sound collection unit of the loudspeaker.

  The loudspeaker 300 includes a microphone array 301 in which a plurality of microphones are arranged in one or a plurality of rows, and the microphone array 301 is connected to the sound collection unit 310. As shown in FIG. 1 (A), the sound collection unit 310 is generated at a specific position (focus position) by adding and synthesizing the sound collected by each microphone of the microphone array 301 with an appropriate time delay. Sound is picked up (collected) with high gain and high S / N ratio.

  As shown in FIG. 2B, the sound collection unit 310 includes an A / D converter array 320 that converts audio signals collected by the microphones of the microphone array 301 into digital signals. Also, a sound collection beam having a delay circuit array 322 that takes in a sound signal of each microphone converted into a digital signal, and delays the sound collection sound of each delayed microphone, and an adder 323 that adds and synthesizes the sound collection sound of each delayed microphone. A plurality (n) of forming units 321 are provided in parallel to the microphone array 301 (A / D converter array 320). Here, the white thick arrow in FIG. 2B indicates that the signals of all the microphones in the microphone array 301 are flowing.

  The n sound collecting beam forming units 321 are set so that different positions become focal positions. That is, different delay times are set in the delay circuit array 322 of each collected sound beam forming unit 321. The sound signal collected by each sound collecting beam forming unit 321 is input to the speaker position detecting unit 311 and the selector 324 shown in FIG.

  In FIG. 2A, the speaker position detection unit 311 monitors the levels of a plurality of audio signals input from the sound collection unit 310, that is, the audio signals collected by the plurality of sound collection beam forming units 321. . When any of the audio signals continues to exceed the predetermined level, it is determined that the audio signal is the voice of the speaker. And it determines with the focus position set to the sound collection beam formation part which picked up the audio | voice signal being a sound source position, ie, a position where a speaker exists.

  The speaker position detection unit 311 notifies the selector (324) of the sound collection unit 310 (see FIG. 2B) the numbers (1 to n) of the sound collection beam forming unit 321 that has collected the uttered speech. . The selector 324 outputs the audio signal picked up by the picked-up sound beam forming unit 321 of that number to the subsequent howling cancel unit 312.

  In addition, the speaker position detection unit 311 notifies the beam control unit 313 of the focal position set in the collected sound beam forming unit 321 that picks up the uttered voice. That is, the speaker position detection unit 311 stores the focal position set in each sound collection beam forming unit 321 (1 to n). The beam control unit 313 performs control so that the virtual focus of the sound emitted from the speaker array 302 becomes the focus position.

  Note that the speaker position detection unit 311 determines that the utterance voice of the speaker is not input when none of the plurality of audio signals input from the sound collection unit 310 exceeds a predetermined level. No number notification or focal position notification to the beam control unit 313 is performed.

  The loudspeaker 300 includes a speaker array 302 in which a plurality of speakers are arranged in one or a plurality of rows. For example, as shown in FIG. 1B, each speaker receives a delayed audio signal. When the audio signal input to each speaker is delayed by a delay pattern as shown in FIG. 1B, the sound emitted from the speaker array 302 diffuses with the position of the speaker 200 as a virtual focus, In addition, it is possible to make the listener listen as if the voice uttered by the speaker 200 is transmitted as it is.

  The sound output unit 314 shown in FIG. 2A performs the amplification of the audio signal and the delay. The sound emitting unit 314 includes the same number of audio amplifiers as the speakers included in the speaker array 302. An audio signal delayed by the delay pattern shown in FIG. 1B is input to each audio amplifier. As a delay circuit for delaying an audio signal input to each speaker in a pattern as shown in FIG. 1B, a delay circuit may be provided individually corresponding to each speaker. A shift register provided with a corresponding tap may be provided, and an audio signal delayed by the delay pattern may be extracted from each tap.

  The audio signal input to the sound emitting unit 314 is an audio signal output to the howling cancel unit 312 as an uttered audio by the selector 324 of the sound collecting unit 310 according to an instruction from the speaker position detecting unit 311, that is, an uttered audio signal. The howling cancel unit 312 cancels howling by attenuating a steep peak of a specific frequency with a notch filter, and inputs this signal to the sound emitting unit 314.

  As described above, this loudspeaker can collect the voice of the speaker 200 with a high gain by using the beam-like sound collection function of the microphone array 301, and can detect the position of the speaker 200. Can do. Further, the collected speech sound signal is emitted in a beam shape by using the speaker array 302 with the position of the speaker 200 as a virtual focus, so that the expanded speech is also the speaker as in the direct speech of the speaker 200. It can be transmitted so as to diffuse from 200 positions.

≪Explanation of loudspeaker unit≫
Next, a loudspeaker unit used in this loudspeaker will be described with reference to FIGS. The loudspeaker of the present invention is configured by connecting one loudspeaker unit or a plurality of loudspeaker units. This loudspeaker unit is also used as an audio conference device for conducting an audio conference with a remote place via a telephone line or a network.

  FIG. 3 is an external perspective view of the loudspeaker unit, and FIGS. 4A, 4B, and 4C are a front view, a bottom view, and a rear view of the loudspeaker unit, respectively. This loudspeaker unit has two rows of 16 microphone arrays on the front and rear sides of the housing (see FIGS. 4A and 4C) and one row (16) on the bottom surface of the housing. (See FIG. 4B).

  In the description of this embodiment, the surface shown in FIG. 4A (the longitudinal side surface shown in FIG. 3) is called the front, front, or front side of the audio conference apparatus (housing), and FIG. ) Is referred to as the back, rear, or rear side of the audio conference apparatus (housing). Accordingly, the right end in FIG. 4A is the right side, and the left end is the left side. The right side surface is the short side surface shown in FIG.

  In FIG. 3, the loudspeaker unit 1 includes a housing 112, legs 113, and an operation unit 114. The housing 112 has a substantially rectangular parallelepiped shape that is long in the left-right direction, and leg portions 113 are provided at both left and right ends. The leg 113 supports the housing 112 in a state where it is lifted by a predetermined height from the installation surface such as a conference desk. In the following description, among the four side surfaces of the housing 112, the front and rear side surfaces are referred to as long surfaces, and the left and right side surfaces are referred to as short surfaces.

  An operation unit 114 including an LCD display 41 and a plurality of buttons 42 is installed at the right end of the upper surface of the housing 112. The operation unit 114 is connected to the main control unit 10 installed in the housing 112. The operation button 42 receives an operation input from a meeting attendee and transmits it to the main control unit 10. The LCD display displays the operation content and execution mode.

  An input / output terminal group is embedded in the right side surface of the housing 112. That is, a network connection terminal 61 to which a network cable is connected, line output terminals 62L and R (OutL, R) as audio input / output terminals, and line input terminals 63L and R (InL, R) are embedded. The line output terminals 62L, R (OutL, R) and the line input terminals 63L, R (InL, R) may be analog signal terminals such as pin jacks or digital audio terminals such as optical fibers. Although not shown, a power supply terminal for connection to a power supply is also embedded in the right side surface.

  Speakers SP <b> 1 to SP <b> 16 having the same specifications are installed on the lower surface of the housing 112. These speakers SP1 to SP16 are installed in a straight line at regular intervals along the longitudinal direction, thereby constituting a speaker array SPA. On the front side surface of the housing 112, microphones MIC101 to MIC116 having the same specifications are installed. These microphones MIC101 to MIC116 are installed in a straight line at a predetermined interval along the longitudinal direction, thereby forming a front-side microphone array MAF. In addition, microphones MIC201 to MIC216 having the same specifications are also installed on the rear side of the housing 112. These microphones MIC201 to MIC216 are also installed in a straight line at predetermined intervals along the longitudinal direction, and thereby a microphone array MAR on the back side is configured. A bottom mesh 121 that is punch-meshed is provided on the lower surface, front side surface, and rear side surface of the housing 112 so as to cover the speaker array and the microphone array.

  In this embodiment, the number of speakers in the speaker array is 16 and the number of microphones in each microphone array is 16. However, the present invention is not limited to this, and the number of speakers and the number of microphones may be set as appropriate according to the specifications. That's fine. In the present embodiment, the speaker array and the microphone array are arranged at equal intervals, but may be appropriately arranged according to the specification. For example, the aspect arrange | positioned densely in the center part along the elongate direction, and arrange | positioned sparsely as it goes to both ends may be sufficient.

  FIG. 5 is a block diagram of an audio signal processing system of the loudspeaker unit 1. The loudspeaker unit 1 includes a main control unit 10, a mixing unit 11, a sound emission control unit 12, a D / A converter 13, a sound emission amplifier (AMP) 14, a sound collection amplifier (AMP) 15, an A / D converter 16, and a sound collection unit. A control unit 17, a howling cancellation unit 18, a communication control unit 19, an operation unit 114, speakers SP1 to SP16, microphones MIC101 to MIC116, and MIC201 to MIC216 are provided.

  The microphones MIC101 to MIC116 and MIC201 to MIC216 collect incoming voices, convert them into electrical sound collection signals, and input them to the sound collection amplifier 15. The sound picked up by each microphone includes uttered sound from a speaker who is present around the apparatus. The sound collection amplifier 15 amplifies the sound collection signal and inputs it to the A / D converter 16. The A / D converter 16 converts an analog sound collection signal into a digital signal and inputs the digital signal to the sound collection control unit 17.

  The sound collection control unit 17 is a functional unit corresponding to the sound collection unit 310 in FIG. The sound collection control unit 17 forms sound collection beams in a plurality of directions in parallel using the sound collection signals of the microphones MIC101 to MIC116 and MIC201 to MIC216. The sound collection control unit 17 has a plurality of sound collection beam forming units in parallel like the sound collection unit 310 shown in FIG. 2B, and as shown in FIG. Using the sound signals picked up by the microphones MIC101 to MIC116), sound pickup beams BFC, BFL1, BFL2, BFR1, BFR2 on the front side are formed. Further, using the audio signal collected by the rear microphone array (microphones MIC201 to MIC216), the rear acoustic beam BRC, BRL1, BRL2, BRR1, and BRR2 are formed.

  The sound collection beam BFC is formed toward the front on the front side of the apparatus. The sound collection beam BFL1 is formed in the direction of about 20 degrees to the left on the front side of the apparatus. The sound collection beam BFL2 is formed in the direction of about 40 degrees to the left on the front side of the apparatus. The sound collection beam BFR1 is formed in the direction of about 20 degrees to the right on the front side of the apparatus. The sound collection beam BFR2 is formed in the direction of about 40 degrees to the right on the front side of the apparatus. The focal point is set so that any sound collecting beam is at a distance of about 1 meter from the central axis in the longitudinal direction of the apparatus. The sound collection beam BRC is formed toward the front on the rear side of the apparatus. The sound collection beam BRL1 is formed in the direction of about 20 degrees to the left on the rear side of the apparatus (as viewed from the front side). The sound collection beam BRL2 is formed in the direction of about 40 degrees to the left on the rear side of the apparatus. The sound collection beam BRR1 is formed in the direction of about 20 degrees to the right on the rear side of the apparatus. The sound collection beam BRR2 is formed in the direction of about 40 degrees to the right on the rear side of the apparatus. The focal point is set so that any sound collecting beam is at a distance of about 1 meter from the central axis in the longitudinal direction of the apparatus.

  The sound collection control unit 17 sequentially notifies the main control unit 10 of the level of each sound collection beam signal collected by these ten sound collection beams.

  The main control unit 10 monitors the level of each collected beam signal and determines the presence / absence of a speech signal. That is, when the level of any sound collection beam signal exceeds the threshold level for a certain period of time, the main control unit 10 determines that the sound collection beam signal is an utterance voice signal. When the main control unit 10 determines that one of the sound collection beam signals is an utterance voice signal, the main control unit 10 instructs the sound collection control unit 17 to output the signal to the mixing unit 11 as Ss.

  The speech signal Ss output from the sound collection control unit 17 is output to the line output terminal by the processing of the mixing unit 11 and also input to the howling detection unit 182 of the howling cancellation unit 18. The howling detection unit 182 detects howling based on the audio signal Ss and controls the notch filter 181 (details will be described later).

  The sound emission control unit 12 delays the audio signal Sd supplied to each speaker SP1 to SP16 of the speaker array by an individual delay time for each speaker so as to have a delay pattern as shown in FIG. 1B, for example. Let The main control unit 10 sets how long the audio signals supplied to the speakers SP1 to SP16 are delayed.

  The main control unit 10 sets, in the sound emission control unit 12, the delay time of the audio signal supplied to each of the speakers SP1 to SP16 so that the focal position of the collected sound beam signal determined as the speech audio signal becomes the virtual focus.

  The sound emission control unit 12 inputs the audio signal Sd subjected to the delay process to each D / A converter 13. Each D / A converter 13 converts the input sound emission signal into an analog signal and applies it to each sound emission amplifier 14, and each sound emission amplifier 14 amplifies the analog sound emission signal to each speaker. Give to SP1-SP16. Each speaker SP1-SP16 emits the input audio | voice signal.

  Further, in the mixing unit 11, the mixer 111L superimposes the voice signal Ss collected on the voice signal SdR input from the line input terminal InR (63R) and outputs it to the line output terminal OutL (62L). 111R superimposes the voice signal Ss collected on the voice signal SdL input from the line input terminal InL (63L) and outputs it to the line output terminal OutR (62R). The adder 502 adds the audio signal SdR, the audio signal SdL, and the collected uttered audio signal Ss input from the outside to generate the audio signal Sd, and outputs this to the sound emission control unit 12.

  The line input terminal InL (63L) and the line output terminal OutL (62L) are connected to another loudspeaker unit connected to the left side of the apparatus, and the line input terminal InR (63R) and the line output terminal OutR (62R) are Connected to another loudspeaker unit connected to the right side of the device.

  A notch filter 181 of the howling cancellation unit 18 is inserted between the adder 502 and the sound emission control unit 12. The howling cancellation unit 18 includes a howling detection unit 182 and a notch filter 181. The howling detection unit 182 performs an FFT on the audio signal Ss output from the sound collection control unit 17 and monitors whether or not a steep peak continues for a certain time or more. When a steep peak continues for a certain time or more, it is determined that the peak component is a howling sound, and the notch filter 181 is set to remove the frequency component. The notch filter 181 is a filter that sharply attenuates only a specific frequency component of the filtered audio signal into a narrow band, and the notch frequency is set by the howling detection unit 182. When the howling detection unit 182 does not detect howling, the notch filter 181 is set not to function.

  The communication control unit 19 is a control unit for performing data communication with another loudspeaker unit or the like via the network connection terminal 61. The network connection terminal 61, the line input terminals InL and InR, and the line output terminals OutL and OutR are used when the loudspeaker according to the embodiment of the present invention is configured by a plurality of loudspeaker units.

≪Example of configuration using multiple sound amplifying units≫
FIG. 7 shows an example in which a plurality of loudspeaker units are connected to form a loudspeaker unit of the present invention. This figure is an example in which four loudspeaker units 1A, 1B, 1C, and 1D are connected in a row to constitute a loudspeaker unit. However, when multiple loudspeaker units are connected, the number is limited to four. Not. Further, the arrangement form is not limited to one linear shape, and may be a polygonal line shape or the like. It is only necessary that a controller unit described later stores the arrangement form.

  In FIG. 7, four loudspeaker units 1A, 1B, 1C, 1D are connected in a straight line via a digital audio cable and a network cable, and further to the loudspeaker unit 1D at the right end via a network cable. A control unit 2 is connected. The connection form of the digital audio cable and the network cable is daisy chain connection, but the transfer of the digital audio signal and the transfer of the data have almost no delay and are high speed.

  The voice signal collected by each loudspeaker unit is transmitted to another loudspeaker unit via a digital audio cable. The loudspeaker unit that picks up the uttered voice signal transmits the picked-up position information of the uttered voice signal to the control unit 2 via the network cable.

  The control unit 2 stores a sound collection beam coordinate table shown in FIG. 8A and an installation coordinate table of each of the loudspeaker units 1A to 1D shown in FIG. The sound collection beam coordinate table is the same as that stored in the main control unit 10 of each loudspeaker unit, and stores the coordinate position of the focus of each sound collection beam. In the sound collecting beam coordinate table, the coordinates of the focal point are represented by polar coordinates (r, θ) with the center of the apparatus as the origin and the front direction as the 0 degree axis. For example, the focal position of the sound collection beam BFC formed on the front side on the front side is (100 cm, 0 degree). The loudspeaker unit installation coordinate table stores coordinates (X1, Y1)-(X2, Y2) at both ends of the longitudinal center line of each loudspeaker unit. The origin and coordinate axes of the XY coordinates are appropriately set according to the installation location.

  When the sound collection position information obtained by collecting the uttered voice is sent from any of the sound enhancement units, the release of each of the other sound enhancement units is based on the installation coordinates and the sound collection position information (that is, the beam number) of the sound enhancement unit. The delay time of the delay pattern to be set in the sound control unit 12 is set. This delay pattern is a delay pattern for each loudspeaker unit to emit sound with the position of the speaker as the virtual focus.

  FIG. 7 shows an example in which the speaker 200A on the rear side of the loudspeaker unit 1A at the left end speaks and the loudspeaker unit 1A picks up the speech. When the loudspeaker unit 1A detects that the collected voice signal is a speech voice signal, the loudspeaker unit 1A transfers the voice signal to each of the other loudspeaker units 1B, 1C, and 1D via a digital audio cable. The loudspeaker unit 1A detects the speaker position of the speech signal, and transfers the speaker position information (beam number) and the unit ID of the own device to the control unit 2 via the network cable.

  The control unit 2 receives the unit ID of the loudspeaker unit 1A and the speaker position information, determines the delay pattern of the loudspeaker units 1B, 1C, and 1D based on the unit ID and the speaker position information, and each loudspeaker unit 1B. , 1C, 1D, the delay time of the determined delay pattern is transmitted.

  Each of the sound amplifying units 1B, 1C, and 1D emits the speech audio signal transferred from the sound amplifying unit 1A by beam control using the delay time transmitted from the control unit 2. Note that the loudspeaker unit 1A that picks up the uttered voice signal controls the sound output beam in accordance with the position of the speaker in the same manner as its own device that constitutes the loudspeaker of the present invention with one loudspeaker unit. Sounds an audio signal.

  When a loudspeaker is configured by connecting a plurality of loudspeaker units, a loudspeaker unit that collects speech (the microphone is turned on) (hereinafter referred to as “sound pickup loudspeaker unit”) is a speaker. , And a loudspeaker unit that does not collect speech (hereinafter referred to as a “non-speech loudspeaker unit”) outputs the forwarded speech (speaker turned on) and turns off the microphone. You may do it. By setting the microphone / speaker on / off in this manner, echo and howling can be efficiently prevented.

FIG. 9 is a flowchart showing the operations of the main control unit 10 and the control unit 2 of each loudspeaker unit shown in FIG.
FIG. 4A is a flowchart showing the operation of the main control unit 10 of each loudspeaker unit. The main control unit 10 waits until the sound collection control unit 17 detects that the utterance voice signal has been collected (S1), or the utterance voice signal is line-inputted from another loudspeaker unit (S2). .

  When it is detected that the utterance voice signal has been collected by the sound collection control unit 17 (YES in S1), the main control unit 10 sends the utterance voice signal to the sound collection control unit 17 via the mixing unit 11. To output a line (S3). Then, the speaker position is detected based on the focal position of the sound collecting beam that picks up the utterance voice signal (S4), and the sound emission control is performed so that a sound emitting beam focused on this position is formed. Set in section 12 (S5). Then, the unit ID of the own device and the speaker position information are transmitted to the controller unit 2 (S6).

  Further, when the speech voice signal is input from another sound collecting unit (YES in S2), it is determined whether a delay pattern (delay time of each speaker SP1 to 16) is received from the control unit 2 ( S7). If a delay pattern is received (YES in S7), the delay time of this delay pattern is set in the sound emission control unit 12 (S8), and the virtual focus matches the speaker position with the sound emission control unit 12 The sound beam is controlled. On the other hand, when the delay pattern has not been received from the control unit 2 (NO in S7), a delay time for controlling the sound emission beam in the front direction is set in the sound emission control unit 12 (S9).

  Even if the delay pattern is delayed from the control unit 2 due to the processing of S7 and S9, the sound emission beam is set in the front direction and the sound emission is started, and the delay pattern is transmitted from the control unit 2. When it is, it becomes possible to re-control the sound emission beam in the direction of the delay pattern.

  FIG. 5B is a flowchart showing the operation of the control unit 2. When the control unit 2 receives the unit ID and the speaker position information from the loudspeaker unit 1 (S11), the received unit ID and the speaker position information are used to collect the sound collecting beam coordinate table shown in FIGS. 8A and 8B. The loudspeaker unit installation coordinate table is searched to determine the delay pattern of each non-pickup loudspeaker unit (S12), and the determined delay pattern (delay time information) is transmitted to each nonpickup loudspeaker unit (S13).

  Note that the delay pattern of the non-pickup loudspeaker unit, that is, the delay time of each speaker SP1-16 of the nonpickup loudspeaker unit may be calculated every time in S12, but the speaker position information output by the picked up loudspeaker unit 6 is limited to the focus positions of several sound pickup beams set in advance as shown in FIG. 6, the delay pattern of each non-sound pickup unit corresponding to each focus position (delay time set for each speaker) ) May be calculated and stored in advance, and this may be read in S12.

  In this embodiment, the control unit 2 is connected to determine the delay pattern of the non-sound pickup loudspeaker unit. However, when the delay pattern is calculated by each non-sound pickup loudspeaker unit, or the speech signal is The control unit 2 is not necessary when the delay pattern of the other non-sound pickup loudspeaker unit can be calculated with the picked up loudspeaker unit.

≪Other configuration examples≫
With reference to FIG. 10, FIG. 11, the other structural example of a loudspeaker comprised by the several loudspeaker unit is demonstrated.
In this loudspeaker, the position of the speaker is detected in units of loudspeaker units, and the control of the virtual focus of the sound emission beam is not completely matched with the speaker position.
That is, in the loudspeaker described above, based on “which loudspeaker collects the speech signal” and “which sound gathering beam among the plurality of sound gathering beams collects the speech signal”, Although the speaker position is detected in detail, in this embodiment, the speaker position is determined only by “which loudspeaker unit has collected the uttered voice signal”.

  Also, it is not controlled to the extent that the virtual focus of the sound output beam of the non-speech loudspeaker unit is matched with the speaker position, and the direction of the directivity of the sound output beam is changed slightly from the front direction to the virtual focus direction. Stopped.

  By performing speaker position detection in units of loudspeaker units, the number of detected speaker positions is reduced (in the example of FIG. 7, four types (eight types including front and rear)), and sound emission according to the speaker position It becomes easy to calculate and store the beam delay pattern (delay time of each speaker) in advance.

  In addition, since the control of the virtual focus of the sound emitting beam is not completely matched with the speaker position, the sound emitting beam of the non-sound collecting unit can be prevented from being turned sideways. That is, in the example of FIG. 7, the direction of the sound emission beam of the loudspeaker unit 1D at the end opposite to the speaker 200A is almost diagonally at a deep angle in the lateral direction, which can be prevented. it can.

  Therefore, in this embodiment, when the utterance voice signal is transferred from the left loudspeaker unit, the beam direction is previously tilted to the left by an appropriate angle, and the utterance voice signal is transferred from the right loudspeaker unit. Is processed by tilting the beam direction to the right by an appropriate angle. Even in this process, it is possible to reduce a sense of incongruity that a loud sound is heard from the front direction when a speaker in any direction speaks.

  For example, as shown in FIGS. 10 (A), (B), and (C), delay patterns for controlling the beam direction of the sound emission beam are stored in three patterns of the front direction, the left direction, and the right direction. When the apparatus detects an utterance voice signal, the beam direction is controlled in the front direction as shown in FIG. 10A, and when the utterance voice signal is transferred from the left sound emitting unit, the beam direction is controlled. 10B is controlled to the left as shown in FIG. 10B, and when the speech signal is transferred from the right sound emitting unit, the beam direction is controlled to the right as shown in FIG. 10C. You may make it do.

In this case, the sound collection and amplification unit that detects the speech signal may control the sound emission beam in the front direction regardless of the speaker position.
Also, with this process, it is not necessary to connect the control unit 2 to calculate the delay pattern.

  FIG. 11 is a flowchart showing the operation of the main control unit 10 of each loudspeaker unit for realizing this embodiment. The main control unit 10 waits until the sound collection control unit 17 detects that the utterance voice signal has been collected (S21) or the utterance voice signal is line-inputted from another loudspeaker unit (S22). .

  When it is detected that the utterance voice signal has been collected by the sound collection control section 17 (YES in S21), the main control section 10 sends the utterance voice signal to the sound collection control section 17 via the mixing section 11. To output a line (S23). Then, a delay time of a delay pattern as shown in FIG. 10A is set in the sound emission control unit 12 so that the uttered voice signal is collected in the front direction (S24). Then, the unit ID of the own device is transmitted to the other loudspeaker units (S25). Each loudspeaking unit has a table in which it is registered whether another loudspeaker unit identified by the unit ID is on the left or right of the own device.

  If the speech audio signal is input from another loudspeaker unit (YES in S22), it is determined whether the unit ID is received from the sound pickup loudspeaker unit via the network (S27). If the unit ID has already been received (YES in S27), the delay time is set in the sound emission control unit 12 so that the loudspeaker beam is tilted in the direction of the loudspeaker unit identified by the unit ID (S28). In other words, when the loudspeaker unit connected to the left side is a sound collection loudspeaker unit, the delay time of the delay pattern as shown in FIG. 10B is set in the sound emission control unit 12 and connected to the right side. If the sound enhancement unit is a sound collection sound enhancement unit, a delay time of a delay pattern as shown in FIG. On the other hand, if the unit ID has not been received yet (NO in S27), a delay time for controlling the sound emission beam in the front direction is set in the sound emission control unit 12 (S29).

  Even if the reception of the unit ID from the sound pickup loudspeaker unit is delayed due to the processing of S27 and S29, the sound emission beam is set in the front direction for the time being and the sound emission is started. It becomes possible to re-control the sound output beam in the direction of the ID loudspeaker unit.

  In the flowchart of FIG. 11, when the main control unit 10 detects the collection of the uttered voice (YES in S21), that is, when the own apparatus becomes a sound collection loudspeaker unit, the collected utterance voice signal is collected. The sound emission beam is controlled so that sound is emitted in the front direction (S24). However, as another example, in the case of a sound collection loudspeaker unit, processing step S4 of the flowchart of FIG. As shown in S5, the speaker position may be detected, and the sound emission beam may be controlled so that the speaker position becomes a virtual focus.

  In this embodiment, the loudspeaker installed in the conference room is described, and the speech voice signal of the speaker is exemplified as the target voice signal. However, the location of the loudspeaker of the present invention is not limited to the conference room, and The target voice signal collected by the loudspeaker of the present invention is not limited to a human voice.

  In this embodiment, the microphone array is used to pick up sounds from a plurality of speaker positions (sound source positions), but the microphone is not limited to this. For example, an individual microphone may be installed in each place where the speaker position is possible. In this embodiment, the speaker array is used to emit sound signals with directivity, but the speaker is not limited to this. For example, a speaker device whose direction can be physically changed may be used.

The figure explaining the sound collection system of the loudspeaker which is embodiment of this invention, and a sound emission system The figure explaining the schematic structure of a loudspeaker External perspective view of a loudspeaker unit constituting a loudspeaker Bottom view and front / rear side view of loudspeaker unit Loudspeaker block diagram The figure which shows the example of the sound collection beam direction of the loudspeaker unit A diagram showing a loudspeaker configured by connecting a plurality of loudspeaker units. The figure which shows the table set to the control unit of the same loudspeaker Flow chart showing the operation of the loudspeaker unit and the control unit of the loudspeaker The figure which shows the other example of sound emission beam control in the loudspeaker comprised by connecting two or more loudspeaker units. The flowchart which shows operation | movement of the loudspeaker unit to which the said other example is applied. The figure explaining the sound emission direction in the conventional loudspeaker

Explanation of symbols

1 (1A-1D) Loudspeaker unit 200 (200A) Conference attendee 300 Loudspeaker 321 Sound collecting beam forming unit

Claims (5)

A sound collection unit for collecting a target voice signal that is a voice signal to be emitted;
A sound source position detector that detects a sound source position that is a position where the target audio signal is generated;
A sound emitting unit capable of controlling the directivity of a sound signal to be emitted, which emits the target sound signal and controls the directivity in a direction in which it is diffused from the sound source position detected by the sound source position detecting unit. A sound emission part,
Loudspeaker with The sound emission part is composed of a plurality of sound emission units,
The loudspeaker according to claim 1, wherein the directivity of the target voice signal emitted by each sound emitting unit is controlled in a direction in which the sound signal is diffused from the sound source position. The sound collection unit has a sound collection characteristic having directivity in a specific direction by delaying and synthesizing a microphone array formed by arranging a plurality of microphones and an audio signal collected by the plurality of microphones. A sound collection control unit for collecting an audio signal,
The sound source position detection unit includes means for determining that a sound source position exists in a directionality direction when the target audio signal is collected.
The loudspeaker according to claim 1 or 2. The sound collection unit includes a plurality of sound collection units,
The sound source position detection unit includes means for determining that a sound source position exists in a direction of a sound collection unit that picks up the target audio signal.
The loudspeaker according to any one of claims 1 to 3.   5. The sound emission unit emits a target sound signal with directivity in a predetermined specific direction until the sound source position detection unit detects the sound source position. The loudspeaker described.

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