JPH0946800A - Sound image controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound image controller capable of reproducing a sound field satisfactorily even when the position of the listener is moved. SOLUTION: This controller is the sound image controller 1 used when an audio signal is reproduced by using at least two loudspeakers. and it is provided with a position detecting part 14 which detects the coordinate positions of right and left ears of the listener in the sound field reproduced by the loudspeakers 13L, 13R, and a signal processing part 11 to control the orientation direction of a sound image in the sound field by the audio signal, and the signal processing part 11 is constituted so as to correct the displacement of the sound image by the displacement of the right and left ears of the listener due to the displacement from a specific position in the sound field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound image control device used when an acoustic signal is reproduced by at least two speakers.

[0002]

2. Description of the Related Art Conventionally, a two-channel stereo acoustic signal is generally reproduced by two speakers arranged on the left and right. The listener can feel a sound image and localization faithful to the sound source by listening at the other vertex of the equilateral triangle having the two vertices as the two vertices.

Further, the acoustic signal includes distance information indicating a virtual distance in the front-rear direction between the listener and the sound source, and direction information indicating a virtual angular position of the sound source in a horizontal plane centered on the listener. In addition, by performing perspective control and direction control of the sound image based on these information, it is possible to freely control the position of the sound image to give a stereoscopic effect to the listener located in the front center of the two speakers. The sound image control device according to the present invention has been proposed by the present applicant (Japanese Patent Application No. 6-8).
No. 0052).

[0004]

When reproducing the above-mentioned conventional two-channel stereo sound signal, the original stereo effect of the source can be obtained unless the listener is at a specific position of the vertices of an equilateral triangle. I can't.

Also, when reproducing the acoustic signal including the distance information and the direction information, unless the listener is at the apex of the equilateral triangle, which is the front center position of the two speakers, the stereoscopic effect by the sound image control is maximized. I can't enjoy it.

That is, conventionally, it is premised that the listener is located in the front center of the two speakers, and the best sound field is reproduced when listening at such an optimum position. If the listener deviates from the optimum position, the sound field will not be the best.

Usually, the listener often does other things while listening to the reproduced acoustic signal, and in such a case, it is not uncommon for the listener to move and deviate from the optimum position.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sound image control device capable of reproducing a good sound field even when the position of the listener moves.

[0009]

According to a first aspect of the present invention, there is provided a sound image control device used when reproducing an acoustic signal by at least two speakers, the listening in a sound field reproduced by the speakers. Position detecting means for detecting the coordinate positions of the left and right ears of a person, and signal processing means for controlling the localization direction of the sound image by the acoustic signal in the sound field. The control is performed so as to correct the displacement of the sound image due to the displacement of the left and right ears of the person from a specific position in the sound field.

According to a second aspect of the present invention, there is provided a device for detecting the coordinate positions of the left and right ears of a listener, and the listening from a reference position which is a specific position in the sound field reproduced by the speaker. Displacement amount detecting means for detecting the amount of displacement of the left and right ears of a person, and a signal correction for controlling the localization direction of the sound image by the acoustic signal in the sound field so as to cancel the displacement of the sound image by the displacement amount. And processing means.

According to a third aspect of the invention, the sound information of the sound source, distance information indicating a virtual distance between the listener and the sound source in the front-rear direction, and the sound source in a horizontal plane centered on the listener. Is a sound image control device used when reproducing an acoustic signal including direction information indicating a virtual angular position of at least two speakers, the perspective control performing perspective control of a sound image based on the distance information. Means, in-horizontal sound image control means for controlling the direction of the sound image based on the direction information for the 2-channel sound signal output from the perspective control unit, and a listener in the sound field reproduced by the speaker. Position detecting means for detecting the coordinate positions of the left and right ears of the listener, and the perspective control means and the sound image control means in the horizontal plane are arranged in the sound field of the left and right ears of the listener. And controls so as to correct the displacement of the sound image by displacement from the specific position.

A position sensor, an angle sensor, an acceleration sensor, an ultrasonic sensor, an infrared sensor or the like is used as the position detecting means. The position detecting means detects the coordinate position of the left and right ears of the listener or the displacement amount of the coordinate position from the specific position. As a method of expressing the coordinate positions of the left and right ears, various methods such as the position and direction of the listener are possible.

The signal processing means controls the localization direction of the sound image based on the acoustic signal. When the listener moves from the specific position, the signal processing unit corrects the displacement of the sound image due to the displacement, and reproduces the sound field as if the listener was moving at the specific position. An FIR filter or the like is used as the signal processing means. The sound image localization control is performed by setting the coefficient of the FIR filter to an appropriate value.

[0014]

1 is a block diagram functionally showing an audio signal reproducing apparatus 1 equipped with a sound image control apparatus 3 according to the present invention, and FIG. 2 is a block diagram showing a hard circuit of the audio signal reproducing apparatus 1. FIG. 3 is a diagram showing the position of the head HD and the transfer characteristic H.

In FIG. 1, an audio signal reproducing apparatus 1 includes a signal processing section 11, an amplifier 12 (amplifiers 12L and 12R),
The speaker 13L, 13R and the position detector 14 are included. The signal processing unit 11 includes a filter unit 21, a coefficient setting unit 22, a coefficient table 23, and adders 24 and 25. The position detection unit 14 includes a head position sensor 31, a head angle sensor 32, a reference position setting unit 33, and a position calculation unit 34.

Acoustic signal Li input to the left and right input terminals
After localization of the sound image is controlled by the signal processing unit 11, n and Rin are amplified by the amplifier 12 and output as sounds by the two speakers 13L and 13R arranged on the left and right.

As shown in FIG. 3, the listener has his head H
With D at the front center position of the two speakers 13L and 13R and the face directed toward the center of the speakers 13L and 13R,
Listen to the sound output from the speakers 13L and 13R. The position and direction of such a listener is referred to as a reference posture AS. The position of the reference posture AS is the coordinate origin of the sound field reproduced by the speakers 13L and 13R, and the direction of the reference posture AS is the rotation angle θh = 0. The rotation angle θh is measured clockwise from the reference posture AS. In the standard posture AS,
When attention is paid to the coordinate positions Pce of the left and right ears of the listener, it is referred to as a reference position PS. That is, the reference posture AS and the reference position PS are in the same state, but may be referred to as the reference position PS when attention is paid to the coordinate positions Pce of the left and right ears. The reference attitude AS can be any position or direction other than those described above. For example, depending on the indoor conditions, the position or direction that the listener is most likely to take,
Any position or orientation may be adopted, such as the most preferred posture, the relaxed posture, and the most popular posture. Reference posture A
S can be input from the reference position setting unit 33.
For example, in a state in which the listener wants to use the current posture as the reference posture AS, the reference position setting unit 33 performs an input for setting to change the state to the reference posture A.
It can be set as S.

The listener covers the head HD with a cap to which the head position sensor 31 and the head angle sensor 32 are attached, whereby the position and direction of the listener's head HD, that is, the head in the sound field. The coordinate position Pc of the portion HD, the rotation angle θh, the coordinate positions Pce of the left and right ears, and the like are detected. That is, when the listener moves to a new position P1, for example, the amount of movement and the amount of rotation to that position are detected by the head position sensor 31 and the head angle sensor 32. From the output signals S1 and S2 from the head position sensor 31 and the head angle sensor 32, the coordinate position Pce of the left and right ears of the listener at the position P1 and the like are calculated by the position calculation unit 3.
4 is calculated. As the head position sensor 31 and the head angle sensor 32, for example, a piezoelectric gyro sensor or a speed sensor is used. Further, instead of these, the position and direction of the listener may be detected from a distant position by ultrasonic waves or infrared rays.

The filter section 21 includes FIR / LL and FIR.
It is composed of four FIR filters 21a to 21d of / LR, FIR / RL, FIR / RR. These four FIR filters 21a to 21d control the direction and position of the sound image by the acoustic signals Lin and Rin. That is, the direction and the position of the sound image are controlled by setting the coefficients Sa of the FIR filters 21a to 21d differently.

The coefficients S _LL , S _LR , S _RL , and S _RR in the four FIR filters 21a to 21d are based on the transfer characteristics (impulse response) from the two speakers 13L and 13R at the reference position PS to the left and right ears. As a characteristic, a parameter for correcting the variation of the transfer characteristic of the listener at an arbitrary position with respect to the reference characteristic so that the listener can hear as if the listener was at the reference position PS regardless of the arbitrary position. Is.

That is, referring to FIG. 3, the transfer characteristic from the left speaker 13L to the left ear is H _LL , the transfer characteristic from the left speaker 13L to the right ear is H _LR , and the right speaker 13R. To the left ear is H _RL , and the transmission characteristic from the right speaker 13R to the right ear is H _RR . For these transfer characteristics H, a coefficient Sa, which is a parameter for correction, is obtained from the transfer characteristics Hs at the reference position PS and the transfer characteristics Ha at an arbitrary position. These coefficients Sa are obtained in advance and stored in the coefficient table 23. In response to the signal S4 from the position calculation unit 34, the coefficient setting unit 22 reads the coefficient Sa from the coefficient table 23 based on the coordinate positions Pce of the left and right ears indicated by the signal S4, and sets the coefficient Sa in the FIR filters 21a to 21d.

The adder 24 includes FIR filters 21a and 21c.
Output from the FIR filter 21.
Add the outputs from b and d. As a result, localization-controlled left and right acoustic signals Ls and Rs are obtained. The acoustic signals Ls and Rs are amplified by the amplifier 12 and output as sounds from the speakers 13L and 13R.

As shown in FIG. 2, the acoustic signal reproducing device 1
Are AD converters 51 and 52 for AD-converting the input acoustic signals Lin and Rin, an input port 53 for inputting the rotation angle θh, etc., and DA-converting the localization-controlled acoustic signals to obtain the acoustic signals Ls and Rs. DA converter 5 for obtaining
4, ROM 5, DSP core 56 for performing calculation of FIR filter, and ROM 5 in which coefficient Sa is stored as a table
7, and hardware such as the data bus 58. All or part of them can be configured by one DSP element.

Therefore, for example, if the listener receives the reference position P
In the case of S, the FIR filters 21a to 21d pass the input acoustic signals Lin and Rin as they are, so that the sound images and localizations of the acoustic signals Lin and Rin reproduced from the speakers 13L and 13R are kept at the reference position. You can feel it in PS. When the listener moves to an arbitrary position P1, the coefficient Sa corresponding to the position P1 is set in the FIR filters 21a to 21d so that the sounds from the speakers 13L and 13R are directed to the listener at the position P1. The listener at the position P1 can perceive the same sound image and localization as the reference position PS.

That is, the listener listens to the speakers 13L, 1
When the reference position PS, which is the original optimum position for the sound field reproduced by 3R, is moved to an arbitrary position P1 other than that, the sound fields reproduced by the speakers 13L and 13R are controlled so that the position P1 after the movement is The correction is made so as to be the optimum listening position, so that the listener's position P1 is always the optimum listening position. In other words, the speaker 13 is corrected by the correction by the FIR filters 21a to 21d.
This means that the best listening positions for the sound fields reproduced by L and 13R have been expanded.

In the acoustic signal reproducing apparatus 1 described above, the signal processing section 11 corresponds to the position detecting means and the signal correction processing means of the present invention, and the position detecting section 14 corresponds to the position detecting means and the displacement amount detecting means of the present invention. To do. Therefore, the signal processing unit 11 and the position detection unit 14 correspond to the sound image control device 3 of the present invention.

In the example of the acoustic signal reproducing apparatus 1 described above, the two-channel stereo acoustic signals Lin and Rin are input. Such acoustic signals Lin and Rin can be easily obtained from a stereo-recorded compact disc, magnetic tape, record, or the like, or by stereo broadcasting. Such acoustic signals Lin and Rin also include sound information of the sound source, distance information indicating a virtual distance in the front-rear direction between the listener and the sound source, and virtual sound source in a horizontal plane centered on the listener. It can also be obtained from the acoustic signal BS including the direction information indicating various angular positions. Next, an acoustic signal reproducing device 1a for reproducing such an acoustic signal BS from the speakers 13L and 13R will be described.

FIG. 4 is a block diagram functionally showing another example of the audio signal reproducing apparatus 1a including the sound image control apparatus 3 according to the present invention. In the audio signal reproducing device 1a, parts having the same functions as those of the audio signal reproducing device 1 described above are denoted by the same reference numerals, and the description thereof will be omitted or simplified.

In FIG. 4, the acoustic signal reproducing device 1a is
Signal processing unit 11, amplifiers 12L and 12R, speaker 13
The L, 13R, the position detector 14, and the localization controller 15 are included.

As described above, the acoustic signal BS includes the sound source signal BSs which is sound information, the distance information BSd, and the direction information BS.
a. As the distance information BSd, information indicating the position of the sound source with respect to the listener, that is, the front position, the vicinity of the front and rear,
Three pieces of position information of the rear position are included (see FIG. 6). As the direction information BSa, there are eight directions (0 °, 45 °, 90 °, 13 in the horizontal plane centering on the listener.
5 °, 180 °, 225 °, 270 °, 315 °). Distance information BSd and direction information B
The coordinates of the sound source signal BSs are determined by Sa. Therefore, the distance information BSd and the direction information BSa may be collectively referred to as a sound source coordinate BSc.

The localization controller 15 outputs two-channel stereo acoustic signals Lin and Rin based on the sound source signal BSs of the acoustic signal BS and the sound source coordinates BSc. Such a localization control unit 15 is the same as the above-mentioned Japanese Patent Application No. 6-
Details are described as a sound image control device in the specification and drawings of No. 80052. Here, an outline of the localization control unit 15 will be described.

FIG. 5 is a block diagram showing the configuration of the localization control section 15, and FIG. 6 is a diagram showing the positional relationship between a virtually formed listener and a sound image. In FIG. 5, the localization control unit 15
Is composed of a perspective control unit 41 and a horizontal plane sound image control unit 42. The perspective control unit 41, for the sound source signal BSs,
The perspective control of the sound image is performed based on the distance information BSd, and the two-channel sound signals La and Ra are output. The horizontal plane sound image control unit 42 outputs the sound signal L output from the perspective control unit 41.
For a and Ra, the direction control of the sound image is performed based on the direction information BSa, and the acoustic signals Lin and Rin are output.

The perspective control unit 41 includes a delay circuit that delays the sound source signal BSs, a circuit that adjusts the amplitude, and the like to generate a reflected sound for the sound source signal BSs. An indirect sound is generated by multiplying the generated reflected sound by a coefficient according to the distance between the listener and the sound source based on the distance information BSd. Similarly, the amplitude of the signal obtained by adding the indirect sound and the direct sound is changed according to the distance, and the cutoff frequency of the high frequency component of the sound is also changed according to the distance to obtain the left channel sound signal La. , The phase coefficient is set to 1 at the front position and is set to -1 at the rear position to change the phase to obtain the sound signal Ra of the right channel. As a result, it is possible to create the perspective of sound in the front position and the rear position for the single sound source signal BSs. That is, if the position of the sound source virtually formed with respect to the listener is in the front position, the sound image is formed in the front, and if it is in the rear position, the sound image is formed in the rear.

Next, the horizontal plane sound image controller 42 will be described. 7 is a block diagram showing the configuration of the horizontal plane sound image control unit 42, and FIG. 9 is a diagram showing eight directions with respect to the listener, FIG.
0 is a diagram showing a state of transfer characteristics of the speakers SL, SR and the sound image to the listener.

In FIG. 9, sound sources (speakers) are provided around the listener in eight directions (0 °, 45 °, 90 °, 135 °,
180 °, 225 °, 270 °, 315 °) is shown. Horizontal plane sound image control unit 42
The sound image control means that the listener hears the sound image of the sound source signal BSs arranged in any of the eight directions.

The area sandwiched in each direction is called a zone. A zone number is attached to each zone. For example,
Zone 0 is between the 0 ° direction and 45 ° direction of the sound image, and zone 1 is between the 45 ° direction and 90 ° direction of the sound image.

The virtual positional relationship between the listener and the sound image is supplied as direction information BSa on the circumference in the horizontal plane centering on the listener. The direction information BSa may be a mere zone number, but for example, if the sound image is close to the 0 ° direction even in the zone 0, it is desirable that the sound source be heard to be arranged in the direction close to the 0 ° direction. In this embodiment, angle information on the circumference of the horizontal plane is supplied as direction information BSa.

In FIG. 7, the sound image control unit 42 in the horizontal plane
Is composed of a large number of filters 61 (61a ..., 61b), a large number of multipliers 62 (62a ...), and adders 63 and 64. The filter 61 virtually divides the direction in the horizontal plane centering on the listener into eight parts so that a sound image is formed in each direction.
L channel filter 61a ... And R channel filter 61, which have filter characteristics defined separately for right and left
It consists of b ... FIR filters are used as these filters 61, and the filter characteristics thereof are determined by the multiplication coefficient. It should be noted that eight divisions are merely examples, and it is needless to say that the number of divisions may be more than that, and of course, the specific direction may be multi-division depending on the sensitivity.

The FIR FIR ₀ and for R for L ₀ is and has a filter characteristic for forming a sound image in the 0 ° direction.
That is, the left and right sound signals La and Ra are respectively FI for L.
When output as two-channel stereo acoustic signals Lin and Rin through R ₀ and R FIR ₀ , respectively,
The sound image is formed in the 0 ° direction. That is, 0 for listeners
Sounds like there is a sound source in the direction.

The FIR ₁ and the R FIR ₁ for L has a filter characteristic to form a sound image at 45 ° direction. That is, the left and right sound signals La and Ra are respectively L FIRs.
_When output as left and right sound signals of 2-channel stereo through ₁ and R FIR ₁ , a sound image is formed in the direction of 45 °. That is, the listener sounds as if there is a speaker in the 45 ° direction.

FIR ₂ for L to FIR ₇ for L, and F for R
As for IR _{2 to} FIR ₇ for R, the filter characteristics are determined so that a sound image is formed in each corresponding direction as described above. The method of determining the filter characteristics of these filters 61 will be described later.

The multiplier 62 multiplies the output of the filter 61 by a predetermined coefficient based on the direction information BSa. That is, the sound signals La and Ra that have passed through the filter 61 are weighted. For example, if the direction information BSa indicates that the sound image of the zone 0 is close to the 45 ° direction, L
Than the ratio of the left and right sound signals by the use FIR ₀ and the R FIR _0, the multiplication coefficient is set so as to increase the ratio of the left and right sound signals by the FIR ₁ and the R FIR ₁ for L. On the contrary, if the direction information BSa indicates that the sound image in the zone 0 is close to the 0 ° direction, the ratio of the left and right sound signals by the FIR ₀ for L and the FIR ₀ for R is calculated as FIR ₁ for L _1.
Multiplication coefficient is set to be higher than the ratio of the left and right sound signals by the R for FIR ₁ and. Therefore, an inverse interlocking type multiplier can be used as the multiplier 62.

The adder 63 adds the signals that have passed through the L multipliers 62 ... And outputs them as a left channel acoustic signal Lin of the two-channel stereo. Further, the adder 64 is configured to add the signals that have passed through the R multipliers 62 ... And output them as a right channel acoustic signal Rin.

Next, a method of determining the characteristics of the filter 61 will be described. As shown in FIG. 10, the listener's head HD
Alternatively, the sound source SO is arranged, for example, diagonally left rear of the dummy head, and the sound signal is detected by the left and right microphones (not shown) set in the ear portions of the head HD. Then, when the sounds actually output from the left and right speakers SL and SR are actually input to the ears of the head HD, this input sound is detected by the above microphone with respect to the sound from the above sound source SO. If the signal is equivalent to, the listener will hear the sound source as if it were at the SO position.

The symbols shown in FIG. 10 have the following meanings. SO: source K _L, K _R: transfer function (transfer characteristic) from the sound source to the left and right ears H: each of the transfer function from the left and right speakers to the left and right ears (transfer characteristic) E _L, E _R: the dummy head Left and right microphone signals T _L , T _R : Filter characteristics of left and right FIR filters Here, the transfer function H from the left and right speakers SL, SR to the left and right ears is the transfer function from the left speaker SL to the left ear. H _LL , transfer function H _RR from right speaker SR to right ear, transfer function H _LR from left speaker SL to right ear, transfer function H _RL from right speaker SR to left ear
There is. The transfer function H _LL is the time response of the left microphone of the dummy head when a unit impulse is applied to the left speaker SL at time t = 0. The same applies to the other transfer functions H _RR , H _LR , and H _RL .

When the sound signal S is output from the position of the sound source SO, the signals of the left and right ears are expressed by the following equation (1).
It becomes like (2). E _L = SK _L (1) E _R = SK _R (2) When the sound signal S is reproduced from the left and right speakers SL and SR through FIR filters having filter characteristics T _L and T _R , The signals at the left and right ears are calculated by the following equations (3) and (4).
become that way.

E _L = ST _L H _LL + ST _R H _RL (3) E _R = ST _L H _LR + ST _R H _RR (4) From the above equations (1) to (4), the filter characteristic T _L , T _R are obtained as in the following equations (5) and (6).

T _L = (K _L H _RR −K _R H _RL ) / (H _LL H _RR −H _LR H _RL ) ... (5) T _R = (K _R H _LL −K _L H _LR ) / ( H _LL H _RR −H _LR H _RL ) (6) In the case of FIG. 10, it corresponds to the sound image direction of 225 °, and the FI for L
This corresponds to the filter characteristics shown for R ₅ and R FIR ₅ , but the filter characteristics of other FIR filters can be similarly derived based on the experimental results using a dummy head.

According to the above-described horizontal plane sound image control section 42, the directions of the sound signals La and Ra are controlled on the basis of the horizontal plane direction of the sound source with respect to the virtually formed listener, and the left and right speakers SL and SR are controlled. When a sound is emitted, a sound image is formed so that the sound source exists in that direction. As a result, the left and right speakers SL and SR, which are ideally arranged to reproduce the acoustic signals Lin and Rin, can be used to give the listener a perspective (stereoscopic effect) based on the relative positional relationship with the sound source. it can. Furthermore, since the filter outputs that form two sound images existing so as to sandwich the sound source position are selected and the mutual weights are adjusted according to the position information, the movement of the sound images is smoothly controlled.

The acoustic signals Lin and Rin output from the horizontal in-plane sound image control section 42 are input to the signal processing section 11,
Through the processing as described above, the sound is output from the speakers 13L and 13R. When the signal processing unit 11 does not perform any processing, such as when the listener is at the reference position PS, the above-described speakers SL and SR and the speaker 13L,
13R is equivalent in forming a sound field.

In the signal processing section 11, the position P of the listener is
By performing the correction process according to 1, the acoustic signals Lin and Rin output from the localization control unit 15 can always be heard in an optimum state regardless of the position P1 of the listener. In other words, the listener is the speaker 13L, 13R
The sound source signal BSs of the acoustic signal BS is the distance information BSd of the acoustic signal BS, regardless of the position with respect to
And the direction information BSa can be heard faithfully.

Next, another example of the horizontal plane sound image controller 42a.
Will be described. FIG. 8 is a block diagram showing another example of a horizontal plane sound image control unit 42a. In contrast to the above-described horizontal plane sound image control unit 42 including the L and R FIR filter groups (filter 61) having different filter coefficients for forming the sound image in each direction, The horizontal plane sound image control unit 42a includes FIR _m and FIR _{m + 1} which are two FIR filters 61A for L and R (two directions forming one zone). Each FIR filter 61A has a variable coefficient for determining the filter characteristic, and the coefficient can be switched by the direction information BSa.

For example, in the case of eight divisions, if a signal corresponding to zone 0 comes as direction information BSa, FIR
_m is a filter (FIR) for forming a sound image in the direction of 0 °
₀ ), and FIR _{m + 1} serves as a filter (FIR ₁ ) for forming a sound image in the 45 ° direction. If a signal corresponding to zone 7 is received as direction information, FIR _m is 31
Filter for forming a sound image in the 5 ° direction (FIR ₇ )
And FIR _{m + 1} becomes a filter (FIR ₀ ) for forming a sound image in the 0 ° direction.

The multiplier 62A outputs the output of FIR _m and the FIR
The output of _{m + 1} is weighted by multiplying it by a predetermined coefficient according to the direction information BSa. Adder 6
3 adds the signals that have passed through the L multiplier 62A and outputs the result as a left channel acoustic signal Lin of the two-channel stereo. The adder 64 adds the signals passed through the R multiplier 62A and outputs the result as a right channel acoustic signal Rin.

As described above, the localization control unit 15 includes the perspective control unit 41 and the horizontal plane sound image control unit 42 or 42a, so that the two-channel acoustic signals Lin and Rin are obtained from the single sound source signal BSs. It is possible to generate and control the localization of the sound image based on the distance information BSd and the direction information BSa.

In the acoustic signal reproducing device 1a described above, the signal processing unit 11 and the localization control unit 15 are separately configured, and a single sound source signal BSs to a two-channel acoustic signal Lin,
The generation of Rin and the correction of the acoustic signals Lin and Rin are performed separately. However, the FIR filters used in the respective processes are combined using the FIR filter, and the combined FIR filters simultaneously perform those processes. It may be performed. In that case, coefficients are calculated and stored in the coefficient table 23 so that such processing can be performed, and the distance information BSd included in the acoustic signal BS,
Direction information BSa and coordinate positions Pc of the left and right ears of the listener
Based on e or the like, a predetermined coefficient may be read from the coefficient table 23 and set in each FIR filter. FIG.
FIG. 3 is a block diagram showing such a sound image control device 3a.

In FIG. 11, the sound image control device 3a has a localization processing unit 70, a coordinate calculation unit 71, a coefficient setting unit 72, and a coefficient table 73. The localization processing unit 70 includes a left channel localization processing unit 70L and a right channel localization processing unit 70R.
have. Based on the output signals S1 and S2 from the head position sensor 31 and the head angle sensor 32, the coordinate calculation unit 7
The coordinate position Pce of the left and right ears is obtained by 1 and the coordinate position Pce
Based on the ce and the sound source coordinates BSc, the coefficient setting unit 72 reads a predetermined coefficient from the coefficient table 73 and sets it in the localization processing unit 70. The localization processing unit 70 has a function that combines the functions of both the localization control unit 15 and the signal processing unit 11 described above, and the sound source signal B based on the set coefficient.
Ss is processed and the left and right acoustic signals Ls and Rs are output.

According to the sound image control device 3a, the number of FIR filters in the localization processing unit 70 decreases,
The number of coefficients increases. In other words, the number of coefficients is smaller and the memory capacity of the coefficient table 23 is smaller when the sound image control device 3 is used.

According to the above example, the acoustic signals Lin, Ri
Since the sound image localization control for n and the like is performed by setting the coefficient Sa in the FIR filter, reliable control can be performed with a simple configuration.

According to the above-described example, a specific position in front of the center of the left and right speakers 13L and 13R was selected as the specific position in the sound field, and it was fixedly considered, but other positions are set as the specific positions. Also, the specific position may be changed in various ways. In addition, the configuration or processing content of the whole or each part of the audio signal reproduction device 1, 1a or the sound image control device 3, 3a,
The processing timing, the mounting form, and the like can be appropriately changed in accordance with the gist of the present invention.

[0061]

According to the inventions of claims 1 to 3,
A good sound field can be reproduced even when the position of the listener moves. As a result, the best listening position in the sound field reproduced by the plurality of speakers is expanded, and it becomes possible to enjoy a more natural sound, a more stereoscopic sound, and a more effective sound.

According to the invention of claim 3, a sound image having a stereoscopic effect can be obtained by a single acoustic signal, and the stereoscopic effect due to the sound image can be optimized most regardless of the position of the listener. it can.

[Brief description of drawings]

FIG. 1 is a block diagram functionally showing an audio signal reproducing device provided with a sound image control device according to the present invention.

FIG. 2 is a block diagram showing a hardware circuit of the audio signal reproducing device.

FIG. 3 is a diagram showing a position of a head and a transfer characteristic.

FIG. 4 is a block diagram functionally showing another example of an audio signal reproducing device including the sound image control device according to the present invention.

FIG. 5 is a block diagram showing a configuration of a localization control unit.

FIG. 6 is a diagram showing a positional relationship between a virtually formed listener and a sound image.

FIG. 7 is a block diagram showing a configuration of a horizontal plane sound image control unit.

FIG. 8 is a block diagram showing another example of a horizontal plane sound image control unit.

FIG. 9 is a diagram showing eight directions for a listener.

FIG. 10 is a diagram showing a state of transfer characteristics of a speaker and a sound image to a listener.

FIG. 11 is a block diagram showing a sound image control device of another example.

[Explanation of symbols]

 3, 3a Sound image control device 11 Signal processing unit (signal processing unit, signal correction processing unit) 13L, 13R speaker 14 Position detection unit (position detection unit, displacement amount detection unit) 41 Perspective sense control unit (perspective sense control unit) 42 Sound image control section in horizontal plane (sound image control means in horizontal plane) Lin, Rin Acoustic signal BS Acoustic signal BSs Sound source signal (sound information) BSd Distance information BSa Direction information

Claims (3)

[Claims] 1. A sound image control device used when reproducing an acoustic signal by at least two speakers, and position detecting means for detecting coordinate positions of the left and right ears of a listener in a sound field reproduced by the speakers. And signal processing means for controlling the localization direction of the sound image in the sound field by the acoustic signal, and the signal processing means, from the specific position in the sound field of the left and right ears of the listener. The sound image control device is characterized in that it controls so as to correct the displacement of the sound image due to the displacement of. 2. A sound image control device used when reproducing an audio signal by at least two speakers, comprising position detecting means for detecting coordinate positions of the left and right ears of a listener, and a sound reproduced by the speakers. A displacement amount detecting means for detecting a displacement amount of the positions of the left and right ears of the listener from a reference position which is a specific position in the field, and a localization direction in the sound field of the sound image by the acoustic signal, depending on the displacement amount. A sound image control device comprising: a signal correction processing unit for controlling so as to cancel the displacement of the sound image. 3. Sound information of a sound source, distance information indicating a virtual front-rear distance between a listener and the sound source, and virtual angle position of the sound source in a horizontal plane centered on the listener. A sound image control device used when reproducing an acoustic signal including direction information by at least two speakers, the perspective control unit performing perspective control of a sound image based on the distance information, and the perspective control unit. The two-channel sound signal output from the horizontal plane sound image control means for controlling the direction of the sound image based on the direction information, and the coordinate positions of the left and right ears of the listener in the sound field reproduced by the speaker. Position detecting means for detecting, and the perspective control means and the horizontal plane sound image control means,
A sound image control device, which controls to correct displacement of a sound image due to displacement of left and right ears of the listener from a specific position in the sound field.