JP2008205896A - Sound emitting and picking up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound emitting and picking up device capable of easily performing setting that directs a sound beam in a particular direction and lowers volume only in a particular direction. <P>SOLUTION: A control part 4 performs processing for detecting a sound source position, and also analyzes contents of sound picked up by a microphone to extract a command. As an analysis of sound contents, for example, particular sound contents are extracted by sound recognition, and the sound contents are extracted as a command. The control part 4 performs orientation setting processing for setting a delay amount of beam control parts 7A and 7B on the basis of the detected sound source position and command contents. Consequently, a user can easily direct a sound beam in the direction of the user himself and direct the sound beam in other directions only by issuing particular command sound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sound emission and collection device that collects sound and outputs a sound beam having strong directivity in a specific direction.

  2. Description of the Related Art Conventionally, a sound emitting device that outputs an audio beam having strong directivity in a specific direction by delay-controlling an audio signal supplied to each unit of a speaker array is known.

For example, Patent Document 1 proposes an apparatus for specifying a speaker position using a microphone array and directing an audio beam toward the speaker in order to set parameters for controlling directivity, such as the delay amount of each speaker unit. Has been.
JP 2006-270876 A

  However, the apparatus of Patent Document 1 has low versatility because the voice beam is directed toward the speaker. For example, when using in a home, there are users who want to listen to the sound of a movie at a high volume on the one hand, and there are users who want to reduce the sound of the movie to make a phone call on the other hand. There are times when you want to turn down the volume only in a specific direction.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sound emission and collection device that can easily perform settings such as directing an audio beam in a specific direction or lowering the volume only in a specific direction.

  The sound emission and collection device of the present invention includes a sound collection unit that collects sound and outputs a sound collection signal, a sound source position detection unit that detects a sound source position, and emits sound with directivity in a specific direction. A sound emission unit that emits sound, a sound analysis unit that inputs the sound collection signal and extracts a command that indicates directivity included in the sound collection signal, a sound source position detected by the sound source position detection unit, and the sound analysis And a control unit that sets a directivity pattern of the sound emitting unit based on the contents of the command that instructs the directivity extracted by the unit.

  In this configuration, a command indicating directivity is extracted from the collected sound signal. For example, words such as “here” and “sound louder” are extracted by voice recognition. Further, the position of the sound source that is the basis of the collected sound signal is detected. The sound source position is detected by performing linear prediction from the output audio signal of each microphone unit of the microphone array, for example. The directivity is controlled based on these command extraction results and sound source position detection results. There are various modes of setting the directivity. For example, when the word “here” is extracted, an audio beam having a strong directivity is directed in that direction.

  Further, according to the present invention, the voice analysis unit further extracts a command for selecting a source included in the collected sound signal, and the control unit is based on the command for selecting the source extracted by the voice analysis unit. The directivity pattern of the selected source sound is set, and the sound emitting unit is configured to direct the sound of different sources simultaneously in a plurality of directions based on the directivity pattern set by the control unit. It is characterized by emitting sound.

  In this configuration, sound from different sources is emitted with directivity in a plurality of directions. For example, it is possible to provide directivity in a plurality of directions at the same time by individually delaying audio signals input to the respective speaker units of the speaker array. Further, in this configuration, a command for selecting a source is extracted from the collected sound signal. For example, when the voice is composed of two sources “source A” and “source B”, the words “source A” and “source B” are extracted by voice recognition. Only the directivity pattern of the selected source audio is set. Thus, for example, when the word “here” is extracted after the statement “source A”, only the sound of the source A is directed in that direction.

  Further, according to the present invention, the voice analysis unit further extracts a command that is a trigger included in the collected sound signal, and the control unit extracts the command that the voice analysis unit triggers only when the command is extracted. A directivity pattern is then set based on the content of a command that instructs directivity.

  In this configuration, a trigger command is extracted from the collected sound signal. The command serving as a trigger is, for example, the word “command input”. A directivity pattern is set only when this word is recognized. For example, when the word “here” is extracted after the statement “command input”, only the sound of the source A is directed in that direction. If you simply extract the word "here", ignore it. By ignoring unintentionally spoken content, the user's intention to set is reflected.

  Furthermore, the present invention is further characterized in that the voice analysis unit extracts a specific rhythm pattern included in the collected sound signal as a command.

  In this configuration, a specific rhythm pattern is extracted as a command. For example, a short single sound (for example, a clapping voice) that is equal to or higher than a predetermined level is counted, and a command is extracted according to the number of inputs within a predetermined time (eg, 3 seconds). For example, it is determined that “sound is loud” with a single sound, and “sound is small” with twice.

  Furthermore, the present invention is further characterized in that the control unit sets a directivity pattern so that the volume decreases only in a predetermined direction.

  In this configuration, the volume is reduced only in a predetermined direction as an aspect of the directivity pattern. In the case of a speaker array, the sound emitted from each speaker unit is weakened in regions having different phases. Therefore, by controlling the delay amount of the audio signal input to each speaker unit, the directivity can be set so that the volume decreases only in a predetermined direction. In this case, a word such as “mute only here” may be extracted as a command for directivity. As a result, the volume can be lowered only in a specific area where the user wants to be quiet by simply speaking a specific sound.

  The present invention further includes an echo canceller that removes an echo component of the collected sound signal, and the speech analysis unit extracts a command included in the collected sound signal from which the echo canceler has removed the echo component. It is characterized by.

  In this configuration, the echo component is removed from the collected sound signal. Since voice recognition or the like is performed on the collected sound signal after removing the echo component, the accuracy of command extraction is improved.

  According to the present invention, by extracting a command indicating the directivity included in the collected sound signal, the sound beam can be directed in a specific direction or the volume can be decreased only in a specific direction by a user's speech. .

The sound emission and collection device of this embodiment is a device that controls the sound emission directivity based on the sound collected by the microphone. Sound. This sound emission and collection device can be used as a speaker device that emits various audio sources by connecting to a television or an audio device. It can also be used as a device.
Hereinafter, a sound emitting and collecting apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a sound emission and collection device.

  The sound emission and collection device 1 includes a microphone array 2, an input / output interface (I / F) 3, a control unit 4, a speaker array 5, an echo canceller 6, a beam control unit 7A, a beam control unit 7B, a mixer 8, and a D / A. Converters 11 to 18, amplifiers (AMP) 31 to 38, amplifiers (AMP) 41 to 48, A / D converters 51 to 58, a sound collection beam generation unit 61, and a sound collection beam selection unit 71 are provided.

  The microphone array 2 includes a plurality of (eight in the example of the figure) microphone units 21 to 28 arranged in a straight line, and outputs sounds (sound collection signals) collected by the microphone units 21 to 28, respectively. The speaker array 5 is formed by linearly arranging a plurality of (eight in the example shown in the figure) speaker units 51 to 58, and each outputs an input audio signal.

  The collected sound signals picked up by the microphone units 21 to 28 are amplified by the front-end amplifiers 41 to 48 and digitally converted by the A / D converters 51 to 58. The collected sound signal digitized by the A / D converters 51 to 58 is input to the echo canceller 6.

  The echo canceller 6 includes a filter processing unit 60, and inputs audio signals corresponding to the speaker units 51 to 58 input from the mixer 8 to the filter processing unit 60. The filter processing unit 60 filters the audio signals corresponding to the speaker units 51 to 58 to generate a pseudo regression sound signal that simulates the regression audio signal that circulates from the speaker array 5 to the microphone array 2. The filter processing unit 60 subtracts this pseudo-regression sound signal from each collected sound signal to eliminate the echo component, and outputs it to the collected sound beam generation unit 61. Erasing the echo component by the echo canceller 6 improves the accuracy of the sound source position detection process and the command analysis process described later.

  The collected sound beam generator 61 delays and synthesizes the collected sound signals from which the echo components have been removed by the echo canceller 6, thereby converting the collected sound directivity of the microphone array 2 as a whole into a beam. Due to the beam-collected sound directivity, sound generated in a specific region is collected with a high gain. The beam-collected sound directivity is called a sound collecting beam. In the present embodiment, sound collection beams MB11 to MB14 corresponding to the four areas around the microphone array 2 are generated.

  FIG. 2 is a diagram illustrating an example of a sound collecting beam. In the figure, a sound collecting beam generating unit 61 forms a sound collecting beam that focuses on a position to be picked up, and picks up a narrow range of sound with high gain. Here, the sound collection areas P1 to P4 are set in front of the microphone array, for example. The sound collection beam generator 61 synthesizes the audio signals collected by the microphone units 21 to 28 after delaying them so as to be equidistant from the focus (F3 in the figure), thereby combining the sound around the focus (sound collection). The sound generated in the region P3) can be extracted with high gain.

  In FIG. 1, the four sound collecting beams MB11 to MB14 generated by the sound collecting beam generating unit 61 are input to the sound collecting beam selecting unit 71. The collected sound beam selector 71 selects a signal having the highest level among the four collected sound beams MB11 to MB14, and outputs the collected sound beam as a main collected beam to the input / output I / F 3.

FIG. 3 is a block diagram showing the main configuration of the collected sound beam selector 71.
The collected sound beam selector 71 includes a BPF (band pass filter) 171, a full wave rectifier circuit 172, a peak detector circuit 173, a level comparator 174, and a signal selector circuit 175.

The BPF 171 is a band-pass filter having a passband that is a main component band of human speech, and performs band-pass filter processing on the collected sound beams MB11 to MB14 and outputs them to the full-wave rectifier circuit 172. The full wave rectification circuit 172 performs full wave rectification (absolute value conversion) on the sound collection beams MB11 to MB14. The peak detection circuit 173 detects the peaks of the collected sound beams MB11 to MB14 subjected to full-wave rectification, and outputs peak value data Ps11 to Ps14. The level comparator 174 compares the peak value data Ps11 to Ps14 and gives selection instruction data for selecting a sound collecting beam corresponding to the peak value data of the highest level to the signal selection circuit 175. Further, the level comparator 174 also supplies selection instruction data to the control unit 4. The control unit 4 uses the selection instruction data for a sound source position detection process described later. The signal selection circuit 175 selects the sound collection beam indicated by the selection instruction data, and outputs it to the input / output I / F 3 as the main sound collection beam. Further, the signal selection circuit 175 selects the sound collection beam indicated by the selection instruction data, and outputs it to the control unit 4 as the main sound collection beam. The control unit 4 uses the main sound collection beam for command analysis processing described later.
This utilizes the fact that the signal level of the sound collecting beam corresponding to the sound collecting region where the sound source exists is higher than the signal level of the sound collecting beam corresponding to the other region.

  The main sound collection beam input to the input / output I / F 3 (output I / F 30C) is output to other devices when the sound emission and collection device 1 is used as an audio conference device. When output via a network, it is output as audio information of a predetermined protocol.

  The input / output I / F 3 functionally includes an input I / F 30A, an input I / F 30B, and an output I / F 30C, and inputs / outputs audio signals (or audio information) to / from other devices. The audio signal input to the input I / F 30A is output to the beam control unit 7A, and the audio signal input to the input I / F 30B is output to the beam control unit 7B. When voice information is input, it is converted into a voice signal and output.

  The beam controllers 7A and 7B can form a sound beam having strong directivity in a predetermined direction by performing delay processing and gain control on the sound signal input to the speaker units 51 to 58 of the speaker array 5. Conversely, an audio beam whose volume is reduced only in a predetermined direction (hereinafter referred to as an audio dip) can be formed. The delay amount and gain of the audio signal corresponding to each of the speaker units 51 to 58 are set by the control unit 4. The sound emitted from the speaker units 51 to 58 is strengthened in a region having a common phase, and is weakened in a region having a different phase. Therefore, the sound beam can be directed in a specific direction or the sound dip can be directed by controlling the delay amount of the sound signal input to each speaker unit.

  The audio signals output from the beam controllers 7A and 7B are input to the mixer 8. The mixer 8 mixes the audio signals corresponding to the speaker units 51 to 58 output from the beam controllers 7A and 7B, respectively, and outputs them to the echo canceller 6. As described above, the echo canceller 6 generates a pseudo regression sound signal from the audio signals corresponding to the speaker units 51 to 58. Further, the echo canceller 6 outputs audio signals corresponding to the speaker units 51 to 58 to the D / A converters 11 to 18. Audio signals corresponding to the speaker units 51 to 58 are converted into analog audio signals by the D / A converters 11 to 18, respectively, amplified by the amplifiers 31 to 38, and then emitted by the speaker units 51 to 58.

  Here, by performing delay processing so that the beam controllers 7A and 7B output sound beams to different regions, the user can listen to the sound of different sources at each location. For example, as shown in FIG. 4, a user h1 who is at the position of the sofa in the living room can listen to the movie sound (source A), and a user h2 who is at the position of the dining table can listen to music (source B). In addition, even if the movie sound is the same, the user h1 can listen to Japanese sound, and the user h2 can listen to English sound. The source and direction of each sound beam (sound dip) are set by the control unit 4.

  The control unit 4 includes a CPU, and performs sound source position detection processing for detecting the position of the sound source based on the selection instruction data input from the level comparator 174. Most simply, it is determined that a sound source exists in the sound beam collection area indicated by the selection instruction data, and this sound collection area is set as the sound source position. In addition, although not shown in figure, the sound collection signal (sound collection signal which the echo canceller 6 output) which the microphone units 21-28 collected is input, respectively, and other general methods, such as a linear prediction method and the minimum variance method, are used. It may be used to detect the sound source position.

  In addition, the control unit 4 performs a command analysis process for analyzing the main sound collection beam input from the signal selection circuit 175. The command analysis process is a process of performing voice recognition and extracting a command from the voice content of the main sound collection beam. Specifically, the control unit 4 compares the input audio signal with the pattern of the audio signal stored in advance in a memory (not shown) or the like. The comparison method uses a probability model such as a hidden Markov model. When the specific sound content is recognized from the content of the input sound signal, the control unit 4 extracts this as a command. The contents of the command are classified into trigger, source selection, and beam setting.

  The control unit 4 determines in advance a voice (for example, a voice called “command input”) to be extracted as a trigger command, selects the source of the voice signal input after recognizing the trigger voice, and sets the beam. A command extraction process for extracting as a command is performed. If the trigger voice is not recognized, the command extraction process is not executed.

Similarly, the control unit 4 determines in advance the audio content to be extracted as a source selection command. The audio content extracted as a source selection command is, for example, “source A”, “source B”, and the like.
The control unit 4 also determines in advance the audio content extracted as a beam setting command. The audio content extracted as a beam setting command is, for example, “sound up”, “sound down”, or the like.
Note that selection of a source and extraction of a beam setting command are not essential in the present invention.

  In addition to voice recognition, for example, a specific rhythm pattern can be extracted as a command. The control unit 4 counts a single sound (for example, a voice of clapping a hand) that is a sound of a predetermined level or more and has a short time of a predetermined level or more, and extracts a command according to the number of inputs within a predetermined time (for example, 3 seconds). For example, it is determined that “sound is loud” with a single sound, and “sound is small” with twice.

  The control unit 4 performs directivity setting processing for setting the delay amount and gain of the beam control units 7A and 7B based on the sound source position detected by the sound source position detection processing and the command content analyzed by the command analysis processing. Hereinafter, a specific example of the directivity setting process will be described with reference to the drawings. In any example, it is assumed that the user first emits a trigger voice such as “command input”.

  FIG. 5 is a diagram illustrating an example of controlling an audio beam as an example of directivity setting processing. FIG. 3A is a diagram showing an example in which an audio beam is directed toward the user. In the figure, when the user h1 says “Source A here”, the control unit 4 extracts “Source A” as a source selection command and extracts “Here” as a beam setting command. Further, the control unit 4 detects the position of the user h1. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the sound of the source A (movie sound in the example in the figure) is directed to the position of the user h1. As a result, the user h1 can direct the sound beam in his / her direction only by saying “Source A here” at each place.

Next, FIG. 5B is a diagram showing an example of changing the volume of the sound beam directed toward the user. In the figure, when the user h1 says “source A louder”, the control unit 4 extracts “source A” as a source selection command and “sound louder” as a beam setting command. To do. Further, the control unit 4 detects the position of the user h1. Then, the control unit 4 sets the gain of the beam control unit 7A so that the volume of the sound beam of the source A is increased. If the detected position of the user h1 is deviated from the direction of the sound beam, the delay amount of the beam control unit 7A may be set so that the sound beam is directed to the position of the user h1. As a result, the user h1 can increase the volume of the source A only by his / her own position only by saying “Increase the source A sound” at each location.
The example of directivity setting shown in FIG. 5 (A) and FIG. 5 (B) is that when enjoying TV and music at night, when other sounds in the home are loud and it is difficult to hear the sound of the movie, It is suitable for etc.

Next, FIG. 6 is a diagram illustrating an example in which an audio dip is directed toward the user. In the figure, when the user h1 says “source A mute only”, the control unit 4 extracts “source A” as a source selection command and “mute only here” as a beam setting command. To do. Further, the control unit 4 detects the position of the user h1. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the volume of the sound of the source A is reduced only by the position of the user h1 (so that a sound dip indicated by a two-dot broken line in the figure is directed). . As a result, the user h1 can direct the audio dip in his / her direction only by saying “source A mute only here” at each location.
The example shown in the figure is suitable for a case where the user is enjoying television or music and wants to temporarily lower the volume due to an incoming call.

Next, FIG. 7 is a diagram illustrating an example in which an audio beam is directed in a direction other than the user (a specific direction). In FIG. 5A, when the user h1 says “source A opposite direction”, the control unit 4 extracts “source A” as a source selection command and “beam opposite direction” as a beam setting command. Extract. Further, the control unit 4 detects the position of the user h1. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the sound beam of the source A is directed in the direction opposite to the user. Note that the opposite direction refers to a position that is symmetric with respect to the direction axis Y orthogonal to the array major axis direction from the center position O of the speaker array 5. In the example of the figure, the user h2 exists in the direction opposite to the position of the user h1. Therefore, the sound beam of the source A is directed to the user h2.
As described above, the user h1 can direct the sound beam in a direction different from that of the user h1 simply by saying “the direction opposite to the source A” at each place. A plurality of directions in which the sound beam is directed can be set in advance, and the sound beam can be directed in that direction.

In FIG. 5B, the control unit 4 presets a plurality of directions from directions 1 to 3 as directions in which the sound beam is directed. The number of directions to be set is not limited to this example. Here, when the user h1 says “source A direction 1”, the control unit 4 extracts “source A” as a source selection command and “direction 1” as a beam setting command. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the sound beam of the source A is directed in the preset direction 1.
The example in FIG. 7 is suitable when the user is enjoying music and wants other people to listen to it. Further, when the user is enjoying television or music as described above, it is also suitable for a case where a telephone call is received and the user wants to temporarily direct the sound beam in the other direction.

  Next, FIG. 8 is a diagram illustrating an example in which the voice dip is directed in a direction other than the user (specific direction). In FIG. 5A, when the user h1 says “Mute only in the direction opposite to the source A”, the control unit 4 extracts “source A” as the command for selecting the source, and “in the opposite direction as the command for setting the beam”. Just extract "mute". Further, the control unit 4 detects the position of the user h1. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the volume of the sound of the source A is reduced only in the direction opposite to the user (so that the audio dip indicated by a two-dot broken line in the figure is directed). To do. In the example of the figure, the user h2 exists in the direction opposite to the position of the user h1. Therefore, the volume of the sound of the source A is reduced only by the position of the user h2.

  As described above, the user h1 can direct the audio dip in a direction different from that of the user h1 only by saying “mute only in the direction opposite to the source A” at each place. It is also possible to set a plurality of directions in which the voice dip is directed in advance and direct the voice dip in that direction.

In FIG. 5B, the control unit 4 sets a plurality of directions from directions 1 to 3 as directions in which the audio dip is directed. Also in this example, the number of directions to be set is not limited to this example. Here, when the user h1 says “Mute only in source A direction 1”, the control unit 4 extracts “source A” as a source selection command and “mute only in direction 1” as a beam setting command. Extract. Then, the control unit 4 sets the delay amount of the beam control unit 7A so that the audio dip of the source A is directed in the preset direction 1.
The example of FIG. 8 is suitable for the case where it is desired to decrease the volume only in the direction in which the baby is sleeping. Also, if the direction of the telephone in the home is set in advance, it is possible to reduce the volume only in the direction of the telephone when a call is received.

  As described above, according to the sound emission and collection device of the present invention, the user can easily control the sound beam and the sound dip only by emitting sound without having to perform complicated settings by operating the main body or the remote control. Can do.

It is a block diagram which shows the structure of a sound emission and collection apparatus. It is a figure which shows the formation concept of a sound collection beam. 3 is a block diagram illustrating a main configuration of a sound collection beam selection unit 71. FIG. It is the figure which showed an example in the case of listening to the sound of a different source in each place. It is a figure which shows the example which controls an audio | voice beam as an example of a directivity setting process. It is the figure which showed the example in the case of directing an audio | voice dip in the direction of a user. It is the figure which showed the example in the case of directing an audio | voice beam to directions other than a user (specific direction). It is the figure which showed the example in the case of directing an audio | voice dip in directions (specific direction) other than a user.

Explanation of symbols

1-Sound emitting and collecting device 2-Microphone array 3-Input / output interface 4-Control unit 5-Speaker array 6-Echo canceller 7 A, 7 B-Beam control unit 8-Mixer

Claims (6)

A sound collection unit that collects sound and outputs a sound collection signal;
A sound source position detection unit for detecting a sound source position;
A sound emitting part that emits sound with directivity in a specific direction;
A voice analysis unit that inputs the collected sound signal and extracts a command that directs directivity included in the collected sound signal;
A control unit that sets a directivity pattern of the sound emitting unit based on a sound source position detected by the sound source position detecting unit and a content of a command that instructs the directivity extracted by the voice analysis unit;
A sound emission and collection device. The voice analysis unit further extracts a command for selecting a source included in the collected sound signal,
The control unit sets the directivity pattern of the selected source voice based on the command for selecting the source extracted by the voice analysis unit,
The sound emission and collection device according to claim 1, wherein the sound emission unit emits sound of different sources with directivity in a plurality of directions at the same time based on the directivity pattern set by the control unit. The voice analysis unit further extracts a trigger command included in the collected sound signal,
3. The control unit according to claim 1, wherein the control unit sets a directivity pattern thereafter based on the content of the command instructing the directivity only when the voice analysis unit extracts a trigger command. 4. Sound emission and collection device.   The sound emission and collection device according to claim 1, wherein the sound analysis unit extracts a specific rhythm pattern included in the sound collection signal as a command.   The sound emission and collection device according to any one of claims 1 to 4, wherein the control unit sets a directivity pattern so that the volume decreases only in a predetermined direction. An echo canceller for removing an echo component of the collected sound signal;
6. The sound emission and collection device according to claim 1, wherein the voice analysis unit extracts a command included in a sound collection signal from which an echo component has been removed by the echo canceller.

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