JP2009260427A - Speaker device, method and program for processing signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the speaker device capable of localizing a stereo image on a display screen, irrespective of the installed position of a speaker, and to provide the method and the program for processing signals. <P>SOLUTION: The speaker device 1 can compute a position relation between a reference position P and a viewing and listening position as an elevation angle α by measurement using a microphone 70. A frequency characteristic F (-α) corresponding to the computed elevation angle α is selected from parameters memorized beforehand at a memory 80. An equalizer 20 gives the frequency characteristic F (-α) to an audio signal Sin. According to the arrangement, a listener can feels as if the stereo image concerning sound emitted from speakers 61 and 62 is localized in the front direction. Thereby, the stereo image can be localized in the front direction, even if the listener does not perform complicated setup by himself/herself. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sound image localization technique during reproduction of an audio signal.

  In recent years, it has become possible to enjoy televisions and movies on a large screen even in ordinary homes by using thin televisions such as liquid crystal televisions and projection-type video equipment. In addition, when such a video device is used, quality is required for sound, and a separate audio device is often prepared. Such an audio device generally uses many speakers, and can enjoy a realistic sound by creating various sound fields.

By the way, in such audio equipment used simultaneously with video equipment, there are speakers provided on the lower side or upper side of the screen displayed by the video equipment, such as a center speaker and a speaker integrated with a television rack. When sound is emitted from such a speaker, the sound image is localized in a certain direction of the speaker, which is different from the image direction displayed by the video equipment, and a sense of discomfort may be felt. In order to eliminate such a sense of incongruity, a technique is disclosed in which a sound image from a speaker is localized in the screen direction when there is a speaker on the lower side of the display screen (for example, Patent Document 1).
Japanese Patent Laid-Open No. 02-296499

  In the technique disclosed in Patent Document 1, since the positional relationship between the display screen and the speaker is clear, if a viewer's viewing position is estimated, a transfer function for localizing a sound image in the screen direction is previously determined. Can be prepared. On the other hand, when the audio device is different from the video device, the position where the speaker of the audio device is installed on the display screen of the video device varies depending on the viewer. There are various optimum transfer functions depending on the distance from the upper side, the lower side, and the display screen. The transfer function varies depending on the viewing position. For this reason, in the technique disclosed in Patent Document 1, there is a case where an optimal sound image localization is not always obtained.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a speaker device, a signal processing method, and a program that can localize a sound image on a display screen regardless of the installation position of the speaker. .

  In order to solve the above-described problems, the present invention stores a plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component, and a plurality of parameters for realizing a predetermined frequency characteristic corresponding to an elevation angle and a depression angle. Storage means, test signal generation means for generating a test signal, sound collection means that can be installed at a predetermined sound collection position, and the test signal that is emitted from the sound emission means and collected by the sound collection means Based on the calculation means for calculating the relationship between the predetermined reference position and the sound pickup position as an elevation angle or depression angle, and among the parameters stored in the storage means for the input audio signal, the calculation means A frequency characteristic imparting means for imparting a frequency characteristic realized by a parameter according to the elevation angle or depression angle calculated by the test signal, and the test signal or the frequency characteristic imparting means. Providing a speaker apparatus characterized by comprising a supply means for supplying an audio signal whose frequency characteristic is applied to the sound emitting means.

  In another preferred embodiment, the supply means performs an acoustic process on the test signal to sequentially give a plurality of predetermined directivity characteristics to the sound emitted from the plurality of sound emission means, The directivity direction is varied within a predetermined range, and the calculation means calculates the elevation angle or depression angle based on the directivity direction when the sound collection by the sound collection means is maximum.

  In another preferable aspect, the calculating means includes the plurality of sound emitting means from a time from when the test signal is emitted from each of the plurality of sound emitting means until sound is picked up by the sound collecting means. The distance between each of the above and the sound collection position is measured, and the elevation angle or depression angle is calculated based on the measured distance.

  In another preferred embodiment, the supply means emits sound from the plurality of sound emission means by supplying the test signal with different delay times to each of the plurality of sound emission means. A predetermined directivity characteristic is given to the sound to be heard.

  Further, the present invention provides a plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component, a sound collecting means that can be installed at a predetermined sound collecting position, and a predetermined frequency characteristic corresponding to the elevation angle and depression angle. In a signal processing method used in a speaker device having a storage means for storing a plurality of parameters for realization, a test signal generation process for generating a test signal, and a sound collected from the sound emitting means and collected by the sound collecting means A calculation process for calculating a relationship between a predetermined reference position and the sound pickup position as an elevation angle or a depression angle based on the test signal, and a parameter stored in the storage means for the input audio signal. Among them, a frequency characteristic imparting process for imparting a frequency characteristic realized by a parameter corresponding to the elevation angle or depression angle calculated by the calculation means, and the test signal or the previous To provide a signal processing method characterized by comprising a supply step of supplying an audio signal of a predetermined frequency characteristic is imparted in the frequency characteristic applying process to the sound emitting means.

  Further, the present invention provides a computer having a plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component and a sound collecting means that can be installed at a predetermined sound collecting position, in accordance with a predetermined angle corresponding to an elevation angle and a depression angle. Storage means for storing a plurality of parameters for realizing the frequency characteristics of the test, a test signal generation function for generating a test signal, and the test signal emitted from the sound emission means and collected by the sound collection means A calculation function for calculating a relationship between a predetermined reference position and the sound collection position as an elevation angle or a depression angle, and a parameter stored in the storage unit for an input audio signal. A frequency characteristic imparting function for imparting a frequency characteristic realized by a parameter according to the determined elevation angle or depression angle, and the test signal or the frequency characteristic imparting function. The audio signal of which the frequency property has been granted provides a program for realizing the supply function of supplying to the sound emitting means.

  ADVANTAGE OF THE INVENTION According to this invention, the speaker apparatus, the signal processing method, and program which can localize a sound image on a display screen irrespective of the installation position of a speaker can be provided.

  Hereinafter, an embodiment of the present invention will be described.

<Embodiment>
A speaker device 1 according to an embodiment of the present invention is a part of an audio device having a speaker installed on the upper or lower side of a display screen of a video device such as a liquid crystal television, and has a configuration as shown in FIG. It has become.

  The control unit 100 controls each unit of the speaker device 1 as described later.

  The test signal generator 10 generates a test signal TS under the control of the controller 100. The test signal TS may be any test sound as long as it can be picked up by the microphone 70. Examples include random noise with limited bandwidth that allows easy gain measurement, burst signals that allow easy measurement of spatial delay time, and frequency sweep signals that are often used for general sound field measurements. As will be described later, when the switching unit 30 is controlled to output the audio signal Sin to the supply control unit 40, the generation of the test signal TS in the test signal generation unit 10 is stopped. Also good.

  The equalizer 20 is set with a frequency characteristic under the control of the control unit 100, gives the set frequency characteristic to the input audio signal Sin, and outputs it to the switching unit 30.

  Under the control of the control unit 100, the switching unit 30 supplies either the test signal TS input from the test signal generation unit 10 or the audio signal Sin input with the frequency characteristic provided by the equalizer 20 to the supply control unit 40. Output.

  The supply control unit 40 includes a delay unit 41 provided on the signal path to the speaker 61 and a delay unit 42 provided on the signal path to the speaker 62. The delay units 41 and 42 are input with the test signal TS or the audio signal Sin to which the frequency characteristic is given from the switching unit 30, and perform a predetermined amount of delay processing under the control of the control unit 100.

  Here, when controlling the switching unit 30 so that the audio signal Sin is output from the switching unit 30, the control unit 100 fixes the delay amounts of the delay units 41 and 42 to predetermined values, respectively. On the other hand, when control is performed so that the test signal TS is output from the switching unit 30, if the test signals delayed in the delay units 41 and 42 are emitted from the speakers 61 and 62, the sound is emitted with a predetermined directivity characteristic. Delay time is set for each of the delay units 41 and 42. In addition, the control unit 100 sequentially changes the set delay time so that the directivity direction indicated by the directivity characteristic given to the sound emission of the speakers 61 and 62 varies within a predetermined range. Here, the speakers 61 and 62 are arranged in the vertical direction, and the applied directivity direction varies in the vertical direction within a predetermined range. The output of the supply control unit 40 is supplied to the amplification unit 50.

  The amplifying unit 50 includes an amplifier 51 provided on the signal path to the speaker 61 and an amplifier 52 provided on the signal system path to the speaker 61. The amplification unit 50 amplifies the input from the supply control unit 40 and outputs it to the speaker unit 60.

  As described above, the speaker unit 60 has the speakers 61 and 62 arranged in the vertical direction. Each speaker 61, 62 emits the test signal TS or the audio signal Sin supplied from the amplifiers 51, 52. Here, when the test signal TS is emitted from the speakers 61 and 62, the delay direction is changed in the delay units 41 and 42 as described above, so that the directivity direction varies within a predetermined range.

  The microphone 70 is a sound collecting means that can be installed at a predetermined sound collecting position. When the test signal TS is emitted from the speakers 61 and 62, the microphone 70 collects the test signal TS and collects the collected sound. The sound signal is output to the control unit 100. Here, the predetermined sound collection position is a position in the vicinity of the head when the viewer views, and is a position as shown in FIG. FIG. 2 is a diagram showing the positional relationship between the video equipment 200, the audio equipment 300 having the speaker device 1 in part, and the sound collection position of the microphone 70. As shown in FIG. In this example, the predetermined reference position P (the position of the midpoint of the straight line connecting the center points of the speakers 61 and 62) and the center of the display screen of the video equipment 200 are as viewed from the sound collection position of the microphone 70. Are arranged in a vertical direction.

  Here, since the viewer usually watches in front of the display screen of the video equipment 200, the sound collection position of the microphone 70 is generally from the center of the display screen of the video equipment 200 as shown in FIG. It is located on the front direction F. Further, when the sound collection position of the microphone 70 is viewed from the reference position P, it is located in the direction of the elevation angle α.

  Returning to FIG. 1, the description will be continued. The storage unit 80 stores parameters for realizing a predetermined frequency characteristic by the equalizer 20 corresponding to each of a plurality of elevation angles. This elevation angle corresponds to the elevation angle α described above in this example. Hereinafter, the association between the elevation angle α and the frequency characteristic will be described.

  First, head-related transfer functions corresponding to sound sources at various positions in the vertical direction in the front direction (median plane) of the viewer are generated in advance. As a generation method, a known method such as measuring a frequency characteristic with a microphone attached to the ear may be used. Since this head-related transfer function is generated corresponding to the sound source on the median plane of the viewer, it is not necessary to consider the binaural difference, so one head-related transfer function corresponds to one sound source. For example, when the head-related transfer functions are generated at intervals of 5 ° in the range of the elevation angle β = −45 ° to + 45 °, 19 head-related transfer functions are generated. Here, the head-related transfer function corresponding to the elevation angle β is expressed as H (β), and the head-related transfer function corresponding to the elevation angle β = + 20 ° is expressed as H (+ 20 °).

  Here, when sound is emitted from a sound source with an elevation angle β = −20 ° as viewed from the viewer, the sound image is localized in the direction of the sound source (elevation angle β = −20 °). On the other hand, among the head-related transfer functions generated as described above, H (0 °) / H (−20 °) (corresponding to the difference in frequency level between H (0 °) and H (−20 °) ( When calculating with dB as a unit, a frequency characteristic (hereinafter referred to as F (−20 °)) of H (0 °) −H (−20 °) is given to the audio signal related to this sound source. Then, the sound image can be localized in the front direction (elevation angle β = 0 °).

  That is, by giving a frequency characteristic of F (β) to the audio signal emitted from the sound source in the direction of the elevation angle β, the sound image is viewed in the front direction of the viewer, in FIG. It can be localized in the center of the display screen. The parameters for realizing the frequency characteristics for localizing the sound image in the front direction of the viewer are stored in the storage unit 80 as described above. Since β = −α as shown in FIG. 2, it corresponds to the elevation angle α. Then, a parameter for realizing the frequency characteristic of F (−α) is stored. If 19 head-related transfer functions are generated as described above, 19 parameters are stored.

  The operation unit 90 is an operation means such as an operation switch or a remote controller. The viewer operates the operation unit 90 to start adjustment of sound image localization (viewing position measurement mode). The operation unit 90 receives the operation of the viewer and notifies the control unit 100. Hereinafter, a case where the signal output from the switching unit 30 to the supply control unit 40 is the test signal TS is referred to as a viewing position measurement mode, and a case where the signal is the audio signal Sin is referred to as a normal mode. Note that, depending on the operation of the operation unit 90 by the viewer, not only the viewing position measurement mode but also the normal mode can be set, but when the viewing position measurement mode ends, the mode may be switched to the normal mode.

  As described above, the control unit 100 controls the test signal generation unit 10, the equalizer 20, the switching unit 30, and the supply control unit 40. When the viewing position measurement mode is set by operating the operation unit 90, the control unit 100 causes the test signal generation unit 10 to generate the test signal TS, and the switching unit 30 supplies the test signal TS to the supply control unit 40. The delay time is sequentially set so that the directing direction of the sound emitted from the speaker unit 60 is controlled by the supply control unit 40.

  Then, the control unit 100 recognizes the directivity direction when the sound volume level of the sound collection signal related to the sound collection of the test signal TS output from the microphone 70 is maximized, and the reference position P and the sound collection position of the microphone 70. Is calculated as the elevation angle α. Then, the control unit 100 reads out a parameter that realizes the frequency characteristic F (−α) corresponding to the calculated elevation angle α from the storage unit 80 and sets the parameter in the equalizer 20.

  After that, when the normal mode is set by operating the operation unit 90 or the like, the control unit 100 outputs the audio signal Sin given the predetermined frequency characteristic by the equalizer 20 to the supply control unit 40 to the switching unit 30. The delay amount of each of the delay units 41 and 42 is fixed to a predetermined value. The above is the description of the configuration of the speaker device 1.

  Next, the operation of the speaker device 1 will be described. As shown in FIG. 2, the video device 200 is installed on the audio device 300 having the speaker device 1. As described above, when viewed from the viewing position of the viewer, the center of the display screen of the video device 200 and the reference The position P is aligned in the vertical direction.

  First, the viewer performs a setting to localize a sound image related to sound emission from the audio device 300 in the display screen direction of the video device 200. In this case, the microphone 70 is installed at the viewing position near the viewer's head, and the operation unit 90 is operated to set the viewing position measurement mode. Thereby, the test signal TS is emitted from the speakers 61 and 62, and the directivity direction thereof fluctuates in the vertical direction. In this example, the controller 100 controls the elevation direction α so that the directing direction varies within the range of −45 ° to 45 °. Here, a directivity direction SD in FIG. 2 indicates a directivity direction with an elevation angle α = 0 °. When the directivity direction and the direction of the microphone 70 coincide with each other, the sound collection level becomes maximum, and the relationship between the reference position P and the viewing position can be calculated as the elevation angle α. Parameters for realizing the frequency characteristic F (−α) corresponding to the elevation angle α calculated in this way are read from the storage unit 80 and set in the equalizer 20.

  Next, when the normal mode is set, the audio signal Sin corresponding to the video displayed on the video device 200 is emitted from the speakers 61 and 62. Since the audio signal Sin is given the frequency characteristic F (−α) by the equalizer 20, the viewer can feel that the sound image is localized in the direction of the video equipment 200.

  As described above, the speaker device 1 according to the embodiment of the present invention can calculate the positional relationship between the reference position P and the viewing position as the elevation angle α by measurement using the microphone 70. Then, a frequency characteristic F (−α) corresponding to the calculated elevation angle α is selected from the parameters stored in advance in the storage unit 80 and is given to the audio signal Sin by the equalizer 20, thereby allowing the viewer to It can be made to feel as if the sound image related to sound emission from the speakers 61 and 62 is localized in the front direction. Therefore, the sound image can be localized in the front direction without the viewer performing complicated settings. In addition, many recent audio devices have a function of automatically correcting the frequency characteristics at the balance of multiple speakers and the viewing position by installing a microphone, and the sound image position adjustment of the present invention is included in the automatic correction. For example, the viewer can enjoy good sound localization without requiring a new operation.

  As mentioned above, although embodiment of this invention was described, this invention can be implemented in various aspects as follows.

<Modification 1>
In the above-described embodiment, the viewing position is calculated based on the directivity created by the plurality of speakers 61 and 62 arranged in the vertical direction. As another method, the distance between the speaker 61 and the sound collection position of the microphone 70, The viewing position may be calculated from the distance between the speaker 62 and the sound collection position of the microphone 70 and the distance between the speakers 61 and 62. In this case, the speaker device 1 may be configured as shown in FIG. That is, the delay units 41 and 42 of the supply control unit 40 in the embodiment may be the supply units 46 and 47. The supply units 46 and 47 control the supply of the input test signal TS to the amplifiers 51 and 52 under the control of the control unit 100. This control is performed so that one of the supply units 46 and 47 supplies the test signal TS and the other stops supply, and the relationship is reversed after a predetermined time has elapsed. Thus, the test signal TS is emitted from either the speaker 61 or the speaker 62.

  When the microphone 70 picks up the test signal TS, the control unit 100 measures the time from the sound emission timing from each of the speakers 61 and 62 to the sound collection timing at the microphone 70, and from the time and the sound speed, As shown in FIG. 4, the distance A between the speaker 61 and the sound collection position of the microphone 70 and the distance B between the speaker 62 and the sound collection position of the microphone 70 are calculated. A distance C between the speakers 61 and 62 is set in advance. From these three distances A, B, and C, the positional relationship between the reference position P and the sound collection position of the microphone 70 can be calculated. Since other configurations are the same as the configurations in the embodiment, the description thereof is omitted.

  Here, the distance between the sound collection position and each of the speakers 61 and 62 is calculated by emitting the test signal TS in order from each of the speakers 61 and 62. If sound can be emitted, sound may be emitted simultaneously. And the control part 100 can measure each spatial delay time by analyzing the sound-collection signal from the microphone 70, and isolate | separating so that it may respond | correspond to each test signal.

<Modification 2>
In the embodiment described above, the speaker unit 60 is the speakers 61 and 62 arranged in the vertical direction. However, if the speaker unit 60 is arranged in a positional relationship having a vertical component, the speaker unit 60 is arranged in an oblique direction with respect to the horizontal direction. It may be. Further, the number of speakers constituting the speaker unit 60 is not limited to two and may be a larger number.

<Modification 3>
In the embodiment described above, in order to generate the directivity related to the viewing position measurement mode, the delay processing is performed in each of the delay units 41 and 42 of the supply control unit 40, but by the FIR (Finite Impulse Response) filter processing. It may be realized.

<Modification 4>
In the above-described embodiment, the head-related transfer function measured as the frequency characteristic provided by the equalizer 20 is created, but the present invention is not limited to this. The head-related transfer function is related to the physical shape of the body, but it is effective to use the psychoacoustic method more widely. For example, humans have empirically learned that the sound from a sound source placed below attenuates to high frequencies, so that sound image control can be achieved to some extent by adjusting the gain balance between high and low frequencies. is there.

<Modification 5>
Each control in the embodiment described above is performed by a computer such as a magnetic recording medium (magnetic tape, magnetic disk (HDD, FD), etc.), an optical recording medium (optical disk (CD, DVD), etc.), a magneto-optical recording medium, or a semiconductor memory. It can be provided as a program stored in a possible recording medium. It is also possible to download via a network such as the Internet. The program provided in this way is stored in a storage unit or the like, and is executed by a CPU or the like, thereby realizing each control in the embodiment.

It is a block diagram which shows the structure of the speaker apparatus which concerns on embodiment. It is explanatory drawing which shows the relationship between the video equipment which concerns on embodiment, an audio equipment, and the sound collection position by a microphone. 10 is a block diagram illustrating a configuration of a speaker device according to Modification 1. FIG. It is explanatory drawing which shows the relationship between the video equipment which concerns on the modification 1, an audio equipment, and the sound collection position by a microphone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Speaker apparatus, 10 ... Test signal generation part, 20 ... Equalizer, 30 ... Switching part, 40 ... Supply control part, 41, 42 ... Delay part, 46, 47 ... Supply part, 50 ... Amplification part, 51, 52 ... Amplifier, 60 ... Speaker unit, 61, 62 ... Speaker, 70 ... Microphone, 80 ... Storage unit, 90 ... Operation unit, 100 ... Control unit, 200 ... Video equipment, 300 ... Audio equipment

Claims (6)

A plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component;
Storage means for storing a plurality of parameters for realizing a plurality of predetermined frequency characteristics according to elevation angle and depression angle;
Test signal generating means for generating a test signal;
Sound collection means that can be installed at a predetermined sound collection position;
Calculation means for calculating a relationship between a predetermined reference position and the sound collection position as an elevation angle or depression angle based on the test signal emitted from the sound emission means and collected by the sound collection means;
A frequency characteristic providing unit that gives a frequency characteristic realized by a parameter corresponding to an elevation angle or depression angle calculated by the calculation unit among parameters stored in the storage unit to the input audio signal;
A speaker device comprising: a supply unit that supplies the test signal or an audio signal to which a predetermined frequency characteristic is imparted by the frequency characteristic imparting unit to the sound emitting unit. The supplying means performs acoustic processing on the test signal, sequentially gives a plurality of predetermined directivity characteristics to the sound emitted from the plurality of sound emitting means, and changes the directivity direction within a predetermined range. Let
The speaker device according to claim 1, wherein the calculation unit calculates the elevation angle or depression angle based on a directivity direction when the magnitude of sound collection by the sound collection unit is maximum. The calculating means includes each of the plurality of sound emitting means and the sound collecting position from a time from when the test signal is emitted from each of the plurality of sound emitting means until sound is picked up by the sound collecting means. The speaker device according to claim 1, wherein the distance is measured, and the elevation angle or depression angle is calculated based on the measured distance. The supply means supplies a predetermined directivity characteristic to the sound emitted from the plurality of sound emitting means by supplying the test signal with different delay times to each of the plurality of sound emitting means. The speaker device according to claim 2, wherein the speaker device is provided. A plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component, sound collecting means that can be installed at a predetermined sound collecting position, and parameters for realizing a predetermined frequency characteristic according to the elevation angle and depression angle In a signal processing method used in a speaker device having a plurality of storage means for storing,
A test signal generation process for generating a test signal;
A calculation process for calculating a relationship between a predetermined reference position and the sound collection position as an elevation angle or a depression angle based on the test signal emitted from the sound emission means and collected by the sound collection means;
A frequency characteristic applying process for giving an input audio signal a frequency characteristic realized by a parameter corresponding to an elevation angle or depression angle calculated by the calculation means among the parameters stored in the storage means;
A signal processing method comprising: supplying a test signal or an audio signal to which a predetermined frequency characteristic is imparted in the frequency characteristic imparting process to the sound emitting means. A computer having a plurality of sound emitting means arranged in a predetermined positional relationship having a vertical component, and a sound collecting means that can be installed at a predetermined sound collecting position,
Storage means for storing a plurality of parameters for realizing a predetermined frequency characteristic corresponding to the elevation angle and depression angle;
A test signal generation function for generating a test signal;
A calculation function for calculating a relationship between a predetermined reference position and the sound collection position as an elevation angle or depression angle based on the test signal emitted from the sound emission means and collected by the sound collection means;
A frequency characteristic imparting function for imparting a frequency characteristic realized by a parameter corresponding to an elevation angle or depression angle calculated by the calculation means among parameters stored in the storage means to the input audio signal;
A program for realizing a supply function of supplying to the sound emitting means an audio signal to which a predetermined frequency characteristic is imparted in the test signal or the frequency characteristic imparting function.

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