JP2008258675A - Sound image localization processing device or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound image localization processing device that can provide a surround system by front speakers through simple signal processing and give similar side localization effects to a plurality of listeners. <P>SOLUTION: The sound image localization processing device 100 drives two speakers FR and FL disposed on right and left sides in front of listeners based upon a plurality of input sound signals to provide a sound field space with presence for a plurality of listeners, and includes a signal processing means 200 of localizing a sound image by one listener by controlling phases of a right signal indicative of a sound signal to be listened to from a right direction to a listening position of one listener and a left signal indicative of a sound signal to be listened to from a left direction, a band dividing means 200 of dividing the signal-processed sound signals by predetermined frequency bands, and a signal correcting means 200 of controlling the phase of the right signal or left signal having been processed to the listening position of another listener by the divided frequency bands to localize a sound image lateral direction of the other listener. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present application relates to sound image localization processing to be reproduced by changing the position of a sound image, and more particularly to a technical field of sound image localization processing for a plurality of listeners.

  In general, a surround system called a 5.1ch surround system has been put into practical use. The surround system includes a center speaker disposed in front of the listener, front speakers disposed on the left and right sides thereof, a rear speaker functioning as a surround speaker disposed on the left and right sides of the listener, or behind the listener, And a subwoofer that specially spreads low frequencies. Then, the surround system changes the position of the sound image with respect to the listener by, for example, delay-controlling the audio signal input to each speaker, and the listener has a lateral localization effect that the sound image is localized to the side. It has come to be obtained.

  On the other hand, recently, there is a speaker that can change the position of a sound image with respect to a listener by using only front speakers arranged on the front left and right of the listener without using the surround speaker (rear speaker) (for example, , See Patent Document 1).

The surround system disclosed in Patent Document 1 is a signal obtained after mixing left and right surround signals (audio signals) to be supplied to surround speakers arranged on the left and right sides of the listener or behind the listener in the 5.1ch surround system. By processing, it is divided into two signals as a monaural signal, and one monaural signal is input to the center speaker and the other monaural signal is input to the left and right front speakers.
JP 2000-577859 A

  However, in the above-described surround system, the surround system is realized by using filter processing using a transfer function. Processing using transfer functions up to both ears is computationally intensive, and when applied to playback processing for listeners with multiple seats, it is necessary to prepare the filter processing sequentially for each seat. There are many problems to make it practical, such as being unsuitable for tuning when changing seats.

  Further, in the above-described surround system, both surround signals are once converted into a monaural signal, so that the localization of the surround signal cannot be reproduced like the original signal.

  Furthermore, in a surround system that can obtain a lateral localization effect using only a general front speaker, when there are multiple listeners, the central seat listener has a lateral localization effect in which the sound image is localized laterally. Although it is obtained, there is a problem that the area where the effect can be experienced is small, and other listeners cannot effectively experience the effect.

  The present application has been made in view of the above-mentioned problems. As an example of the problem, a surround system is realized with a front speaker by simple signal processing, and a plurality of listeners have the same side. An object of the present invention is to provide a sound image localization processing apparatus capable of obtaining a localization effect.

  In order to solve the above-described problem, the sound image localization processing device (100) according to claim 1 is configured to amplify two speakers arranged on the front left and right of the listener based on the input multi-channel acoustic signals. A sound image localization processing device for laterally locating sound images to a plurality of listeners, the phase of an acoustic signal to be heard from one direction with respect to the listening position of one listener, and the one listener A signal processing means (200) for controlling a phase of an acoustic signal to be heard from one other direction with respect to the listening position to localize a sound image to a side of the one listener, an acoustic signal subjected to signal processing, and Band dividing means (200) for dividing an acoustic signal not subjected to signal processing into predetermined frequency bands, and assigning each listener to each of the divided frequency bands, with respect to the listening position of the other listeners The signal processing Has been said signal correcting means for controlling the time delay of the acoustic signals to localize a sound image on the side of the other of the listener (200), characterized by including the.

  According to another aspect of the sound image localization processing method of the present invention, the two speakers arranged at the front left and right of the listener are loudened based on the input sound signals of the plurality of channels, and the sound image is transmitted to the plurality of listeners. A sound image localization processing method that localizes the sound to the side, the phase of the acoustic signal to be heard from one direction with respect to the listening position of the one listener, and another one with respect to the listening position of the one listener A signal processing step for controlling the phase of the acoustic signal to be heard from the direction to localize the sound image to the side of the one listener, and a signal processing acoustic signal and an unprocessed acoustic signal in a predetermined frequency band A band dividing step for dividing each of the divided frequency bands, and assigning each listener to each of the divided frequency bands, and controlling a time delay of the acoustic signal subjected to the signal processing with respect to the listening position of the other listeners Other listening Characterized by comprising a signal correcting step to localize a sound image, to the side of the person.

  According to a seventh aspect of the present invention, there is provided a sound image localization processing program for causing a computer included in the sound image localization processing apparatus according to claim 1 to listen to a listening position of one listener from one direction. And a signal processing means for controlling a phase of an acoustic signal to be heard from another direction with respect to the listening position of the one listener and localizing a sound image to the side of the one listener, Band dividing means for dividing an acoustic signal and an unprocessed acoustic signal for each predetermined frequency band, assigning each listener for each divided frequency band, and for the listening position of the other listeners It is characterized by functioning as signal correction means for controlling the time delay of the signal processed acoustic signal to localize the sound image to the side of the other listener.

  Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. The sound image localization processing apparatus 100 of this embodiment is an apparatus that localizes sound images to the side of a plurality of listeners using two front speakers 132 arranged on the front left and right of the listener.

  FIG. 1 is a block diagram showing the configuration of the sound image localization processing apparatus of this embodiment, and FIG. 2 is an example for explaining the relationship between the arrangement of each speaker and the seat position of the listener in the sound image localization processing apparatus of this embodiment. FIG. 3 is an explanatory diagram of the lateral localization processing in the signal processing unit.

  As shown in FIGS. 1 and 2, the sound image localization processing apparatus 100 of the present embodiment is installed in a listening room 10, that is, a sound field space for providing a sound to be reproduced to a listener. As shown in FIG. 1, the sound image localization processing apparatus 100 reproduces a sound source such as a recording medium or acquires a sound source from the outside such as a television signal, for each channel corresponding to each speaker. A sound source output device 110 that outputs an audio signal corresponding to each channel, a signal processing device 120 that performs signal processing for each audio signal corresponding to each of a plurality of channels output from the sound source output device 110, and a signal for each channel And a speaker system 130 to which the processed audio signal is input.

  As shown in FIG. 2, a front speaker 132 is arranged as a speaker system 130 in the listening room 10. The front speaker 132 includes a front right speaker FR (hereinafter referred to as an FR speaker) and a front left front speaker FL (hereinafter referred to as an FL speaker) when viewed from the listener side. It is configured. The front speakers 132 are arranged side by side with a predetermined interval, and a seat 15 for a listener to sit is provided in front of the output direction. The seat 15 includes, for example, a central seat 15a arranged with the distance between the FL speaker and the FR speaker set equal, and a right seat 15b and a left seat 15c arranged on both sides thereof.

  Then, the sound image localization processing device 100 uses the front speaker 132 to calculate a difference in sound pressure level generated in both ears of the listener due to sound emitted from a speaker called a surround speaker 135 on the side or rear of the listener. By recreating it, the listener creates a phenomenon in which sound can be heard from the side.

  For example, when a lateral localization effect for localizing a sound image to the listener's side is given to the listener at the central seat 15a, the sound image localization processing device 100 is surrounded by the signal processing unit 200 of the signal processing device 120. A control signal for controlling the phase of the surround signal to be input to the surround speaker 135 is generated in order to reproduce the difference in sound pressure level generated in both ears of the listener due to the sound emitted from the speaker 135, and the surround signal is generated. A control signal is added to and input to the front speaker 132.

  When the listener moves from the central seat 15a to the right seat 15b, the listener approaches the FR speaker and moves away from the FL speaker, and the level of sound heard by the right ear is higher than that of the left ear. . Therefore, in the sound image localization processing device 100, the signal processing unit 200 of the signal processing device 120 generates a control signal that delays the sound signal to be output from the FR speaker for a certain time and attenuates the sound pressure level, and controls the sound signal. A signal is added and input to the front speaker. As a result, the state of listening to the sound at the right seat 15b is equivalent to the state of listening to the sound at the central seat 15a.

  On the other hand, when the listener moves from the central seat 15a to the left seat 15c, the process may be performed in contrast to the case where the listener moves from the central seat 15a to the right seat 15b. That is, the sound image localization processing device 100 generates a control signal that delays the sound signal to be output from the FL speaker by a certain time and attenuates the sound pressure level by the signal processing unit 200 of the signal processing device 120, and controls the sound signal to the sound signal. A signal is added and input to the front speaker. As a result, the state where the sound is heard at the left seat 15c is equivalent to the state where the sound is heard at the central seat 15a.

  However, the area where the lateral localization effect can be experienced is small, and it is difficult for a plurality of people (for example, listeners sitting in the center seat, the right seat, and the left seat) to experience the effect simultaneously.

  Here, a case where listeners exist in each of the central seat, the right seat, and the left seat and a lateral localization effect is given to each listener will be considered.

  As shown above, when a control signal generated to localize the sound image to the side of the listener at each seat is added, the lateral localization effect is simultaneously generated for a plurality of listeners. Since the control signals interfere with each other and the phase of the audio signal output from the front speaker 132 changes, it is usually impossible to cause a difference in sound pressure level for listeners in any seat. It is not possible to give a sufficient lateral localization effect to each listener.

  Therefore, as shown in FIG. 3, the sound image localization processing apparatus 100 of the present embodiment is configured so that sound signals (surround signals) to be input to the left and right surround speakers 135 are localized on the side of each listener. Is output after lateral localization. Specifically, the sound image localization processing apparatus 100 divides a surround signal to be input to the left and right surround speakers 135 into predetermined bands by the signal processing unit 200 of the signal processing apparatus 120, and a plurality of sound signals are processed for each band. A control signal for controlling the phase of the surround signal is generated so that each listener can obtain a lateral localization effect for each band, and a control signal is added to the surround signal and output. It has become. The surround signal to which the control signal is added is input to the front speaker 132.

  According to the sound image localization processing apparatus 100, since the control signal is added for each band of the surround signal, the control signals do not interfere with each other. Therefore, for a listener assigned for each band, the listener can obtain a lateral localization effect in the assigned band.

  In general, in the case of a wideband signal such as a music signal, it is difficult to separate and distinguish the sound for each band, and due to the lateral localization effect in the allocated band, the sound image is laterally transmitted in all frequency bands. It seems that it is localized.

  As described above, according to the sound image localization processing apparatus 100 of the present embodiment, each listener is assigned to each band of the surround signal, and a control signal is generated so that each listener can obtain a lateral localization effect in that band. By combining the control signal with the surround signal and controlling the phase of the surround signal, a plurality of listeners can fully experience the lateral localization effect.

  Here, in order to provide a lateral localization effect with a good balance for a plurality of listeners, a method of assigning each seat (center seat, left seat, right seat) after dividing the surround signal into a band will be examined.

  First, if there is a lot of time fluctuation for a given frequency band for the audio signal, the feeling of localization will be weakened, and the listener will tend not to feel the localization effect of the sound image. A wider bandwidth is better.

  Also, if the right seat and left seat are assigned to the left surround signal that localizes the sound image to the left side of the listener and the right surround signal that localizes the sound image to the right side of the listener, respectively, these are contrasting processes. Therefore, especially when the correlation between the left surround signal and the right surround signal is high, it is considered that both processes cancel each other out, so it is better to assign the same seat to the same frequency band.

  In addition, when the right seat and left seat are assigned to the low range, the listener is easily affected by the head turning around, and one control signal path becomes longer, and the listener is easily affected by the reflection of the room. Because the control signal reaches the ear differently from the desired waveform, the lateral localization effect may be weakened. Therefore, the left seat or the right seat should not be assigned to a low frequency (for example, 400 Hz or less). It is better to assign a central seat.

  In addition, when the right and left seats are assigned to the high range, it is generally known that the level difference has a large effect on the localization in the high range, which is a factor that significantly reduces the lateral localization effect in different seats. Therefore, considering the balance of each seat, it is better to assign a central seat in the high range (for example, 2500 Hz or more).

  Next, a specific cut-off frequency setting when a surround signal is divided into predetermined bands and each seat is assigned to each band will be discussed with reference to FIG. FIG. 4 is an example showing the relationship between the speaker installation position and the listener's seat position.

  First, the relationship between the front speaker and the listening position of the listener is examined.

  The frequency band sound output from the front speaker 132 reaches the listener's listening position as a wave of wavelength. At this time, when a lateral localization effect is given to the listener of the central seat 15a, a sound pressure dip is generated on the sides of both ears by utilizing interference between the surround signal and the control signal. . Therefore, if considered for each frequency, this sound pressure dip periodically appears at a position where the time difference between the surround signal and the control signal is an integral multiple of the signal period (see Equation 1). Therefore, if the cycle matches the arrival time shift due to the seat shift, the listener can obtain the same lateral localization effect even if the seat position is different.

  On the other hand, at positions where the time difference between the surround signal and the control signal is an integral multiple of the signal cycle + a half cycle, the audio signals cancel each other and no sound pressure dip occurs, so the listener can obtain a lateral localization effect. Not (see Equation 2).

For example, as shown in FIG. 4, assuming a situation in which the listener feels the effect in a situation where the listener is sitting side by side in the center seat, the right seat, and the left seat, processing at the center seat is given to other seats. Consider the impact. D ₁ and D _r are distances from the right seat to the front speakers FR and FL, respectively.

The time difference between the surround signal and the control signal emitted from each front speaker in the right seat is as follows.
| D ₁ −D _r | / c
It can be expressed as Since the frequency at which this value is an integral multiple of the period is considered to be able to obtain a lateral localization effect even in the right seat,
| D ₁ −D _r | / c = 1 / f × n (n = 1, 2, 3,...) (Formula 1)
A frequency satisfying the above can obtain a lateral localization effect even in the right seat, and also in the left seat due to symmetry.

  Further, even when the lateral localization process for the right seat or the left seat is performed, the lateral localization effect can be obtained in all other seats by the same calculation.

on the other hand,
| D ₁ −D _r | / c = 1 / f × (n + 1/2) (n = 0, 1, 2, 3,...) (Formula 2)
The frequencies that satisfy the above conditions act so as to cancel each other out, and the effect cannot be obtained in the right seat or the left seat. Since these frequencies can be obtained with every other seat when considering the position of the seat from the cycle, without processing at the center seat, the right seat (or left seat) When processing is performed, the effect at the left seat (or right seat) can be obtained instead of the effect at the center seat. Therefore, it can be considered that these frequency bands can be more effective when the right seat (or left seat) is processed.

  Next, a specific cut-off frequency setting example will be described with reference to FIG. 4 based on the above-described concept of the relationship between the front speaker and the listening position of the listener. In FIG. 4, there are listeners in the center seat, right seat, and left seat, respectively. Here, for example, a setting example of the cut-off frequency when the band is divided into four bands by LPF (low-pass filter), BPF (band-pass filter), and HPF (high-pass filter) will be considered.

  According to Equation 1, when n = 1, the frequency is calculated as 1000 Hz. Here, since n = 1, 2, 3,..., For example, it is understood that any seating process may be performed around 1000 Hz and 2000 Hz.

  On the other hand, according to Equation 2, the frequency is calculated as 500 Hz when n = 0. Here, since n = 0, 1, 2, 3,..., For example, it is understood that it is better to process the right seat or the left seat in the vicinity of 500 Hz and 1500 Hz.

  In addition, since it is considered good to assign a central seat for the low and high ranges and a right seat or a left seat for the middle region, the center frequencies of the two BPFs are preferably set to 500 Hz and 1500 Hz. It is considered more effective if the cut-off frequencies of the respective filters are set so that the two BPFs have the same octave bandwidth.

  Next, a specific configuration and processing of each device of the sound image localization processing device in the present embodiment will be described with reference to FIG.

  The sound source output device 110 is composed of, for example, a media playback device such as a CD (Compact Disc) or a DVD (Digital Versatile Disc) or a reception device that receives a digital television broadcast, or by playing back a sound source such as a CD, or By acquiring the broadcast sound source, an audio signal for each channel corresponding to 5.1 ch is output to the signal processing device 120 as a digital signal.

  An audio signal for each channel output from the sound source output device 110 is input to the signal processing device 120. The signal processing device 120 includes an input processing unit 121 that receives an audio signal input from the sound source output device 110, a signal processing unit 200 that processes the audio signal for each channel, and a digital signal that is signal-processed for each channel. It includes D / A converters 122FL and 122FR that convert audio signals that are signals into analog signals, and power amplifiers 123FL and 123FR that amplify the audio signals converted into analog signals for each channel.

  The signal processing unit 200 controls the phase of the surround signal to be input to the surround speaker under the control of the system control unit 125, generates a control signal for localizing the sound image to the side of the listener, and generates the surround signal. A control signal is added to and output. Note that the surround signal to which the control signal is added is input to the D / A converters 122FL and 122FR for input to the FR speaker and the FL speaker, respectively.

  In addition, the power amplifier 123 amplifies the signal level of the audio signal for each channel based on the instruction of the volume specified by the operation unit 124 under the control of the system control unit 125, and the amplified audio signal is It outputs to the FR speaker and FL speaker corresponding to a channel.

  The operation unit 124 includes a remote control device including various keys such as various confirmation buttons, selection buttons, and numeric keys, or various key buttons.

  The system control unit 125 comprehensively controls general functions for amplifying audio signals from the FR speaker and the FL speaker and performing sound localization processing for a plurality of viewers.

  The channel refers to a signal transmission path of an audio signal output from the sound source output device 110, and each channel transmits an audio signal that is basically different from other channels.

  Hereinafter, the lateral localization processing in the specific signal processing unit will be described.

[First embodiment]
—Example 1—
Next, an embodiment of the signal processing unit when the listener is present in the center seat and the right seat will be described with reference to FIGS. FIG. 5 is a block diagram showing the flow of the surround signal for the left speaker input of the signal processor in the first embodiment, and FIG. 6 is a block diagram showing the flow of the surround signal for the right speaker input of the signal processor in the first embodiment. is there.

  In this embodiment, a surround signal to be input to a surround speaker is divided into a low frequency band and a high frequency band, and a central seat and a right seat are assigned to each of the divided bandwidths. Lateral localization processing is performed for listeners at each seat. In this embodiment, the low range is assigned to the central seat and the high range is assigned to the right seat.

  In the signal processing unit 200 of the present embodiment, first, as shown in FIG. 5, the left surround signal SL to be output to the left surround speaker 135 functioning as the left signal of the present application is the surround signal input to the FL speaker. (Hereinafter referred to as a left speaker input surround signal SLL) and a surround signal input to the FR speaker (hereinafter referred to as a right speaker input surround signal SLR).

  The left speaker input surround signal SLL corresponds to the high frequency band so that the frequency band is divided into a low frequency band and a high frequency band by LPF and HPF, and then the band is flattened and the sound pressure level is equalized. The surround signal is level-corrected (adjusted). Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SLR for right speaker input causes an appropriate time difference in each frequency band, and the side of the listener at the center seat uses an all-pass filter that can change only the phase without changing the amplitude value of each frequency. After the phase control process is performed so that the sound image is localized, the frequency band is divided into a low frequency region and a high frequency region by the LPF and HPF, and the right seat listener side with respect to the surround signal corresponding to the high frequency region On the other hand, a delay and attenuation process is performed so that the sound image is localized. Note that the level of the surround signal corresponding to the high frequency is adjusted so that the sound pressure level is uniform in order to flatten the band. Then, the band-divided surround signals are combined and output. The phase control process may be performed by a combination of a band division filter bank and a delay element.

  Further, in the signal processing unit 200, as shown in FIG. 6, the right surround signal SR to be output to the right surround speaker 135 functioning as the right signal of the present application is converted into a surround signal to be input to the FR speaker (hereinafter, referred to as “the surround signal”). The signal is branched into a surround signal SRR for right speaker input and a surround signal to be input to the FL speaker (hereinafter referred to as a surround signal SRL for left speaker input).

  The surround signal SRR for the right speaker input is divided into a low frequency band and a high frequency band by LPF and HPF, and then a sound image is generated on the side of the right seat listener with respect to the surround signal corresponding to the high frequency band. Delayed and attenuated to localize. It should be noted that the level of the surround signal corresponding to the high frequency is adjusted so that the band is flat and the sound pressure level is uniform. Then, surround signals having different frequency bands are synthesized and output.

  On the other hand, the left speaker input surround signal SRL is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat, and then the frequency band is divided into a low band and a high band by the LPF and HPF. The level of the surround signal corresponding to the high band is adjusted so that the band is flat and the sound pressure level is uniform. Then, surround signals having different frequency bands are synthesized and output.

  The right speaker input surround signals SLR and SRR are combined and input to the FR speaker as a right surround signal, and the left speaker input surround signals SLL and SRL are combined and input to the FL speaker as a left surround signal. It is like that.

  In the present embodiment, the phase of the surround signal is controlled so that the listener at the center seat can obtain a lateral localization effect at a low frequency and the listener at the right seat can obtain a lateral localization effect at a high frequency. As a result, each listener can experience the lateral localization effect at each seat position.

  In the present embodiment, the frequency bands divided in the left surround signal and the right surround signal are the same, but the frequency bands may be different. For example, the frequency divided on the left surround signal side may be set to 400 Hz, and the frequency divided on the right surround signal side may be set to 1 kHz.

—Example 2—
Next, an example of the signal processing unit when the listener is present in each of the central seat, the right seat, and the left seat will be described with reference to FIGS. FIG. 7 is a block diagram showing the flow of the surround signal for the left speaker input of the signal processor in the second embodiment, and FIG. 8 is a block diagram showing the flow of the surround signal for the right speaker input of the signal processor in the second embodiment. is there.

  This embodiment divides a surround signal to be input to a surround speaker into low, middle, and high frequency bands, and assigns a central seat, a right seat, and a left seat to each of the divided bands, Side localization processing is performed for listeners at each seat assigned in each band. In this embodiment, the low range is assigned to the central seat 15a, the middle range is assigned to the right seat 15b, and the high range is assigned to the left seat 15c.

  In the signal processing unit 200 of the present embodiment, first, as shown in FIG. 6, the left surround signal SL to be output to the left surround speaker is a left speaker input surround signal SLL and a right speaker input surround signal SLR. And then branch off.

  The left speaker input surround signal SLL is divided by the LPF, BPF, and HPF into the low frequency, mid frequency, and high frequency, and then the surround signal corresponding to the high frequency is used by the listener at the left seat. Delay and attenuation processing is performed so that the sound image is localized to the side. It should be noted that the surround signals corresponding to the mid range and the high range are level-corrected (adjusted) so that the band is flat and the sound pressure level is equalized. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SLR for right speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by an all-pass filter, and then low, mid, and high by LPF, BPF, and HPF. The frequency band is divided into regions, and a delay and attenuation process is performed so that the sound image is localized to the side of the listener in the right seat with respect to the surround signal corresponding to the middle region. Note that the level of the surround signals corresponding to the mid-range and high-range is adjusted so that the band is flat and the sound pressure level is uniform. Then, the band-divided surround signals are respectively synthesized and output.

  Further, in the signal processing unit 200, as shown in FIG. 7, the surround signal SR to be input to the right surround speaker is branched into a surround signal SRR for right speaker input and a surround signal SRL for left speaker input. The

  The surround signal SRR for the right speaker input is divided by the LPF, BPF, and HPF into the low frequency, mid frequency, and high frequency, and then the right seat's surround signal SRR Delay and attenuation processing is performed so that the sound image is localized to the side. Note that the level of the surround signals corresponding to the mid-range and high-range is adjusted so that the band is flat and the sound pressure level is uniform. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SRL for left speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by an all-pass filter, and then low, mid, and high by LPF, BPF, and HPF. The frequency band is divided into regions, and a delay and attenuation process is performed so that the sound image is localized to the side of the listener in the left seat with respect to the surround signal corresponding to the high region. Note that the level of the surround signals corresponding to the mid-range and high-range is adjusted so that the band is flat and the sound pressure level is uniform. Then, the band-divided surround signals are respectively synthesized and output.

  The right speaker input surround signals SLR and SRR are combined and input to the FR speaker as a right surround signal, and the left speaker input surround signals SLL and SRL are combined and input to the FL speaker as a left surround signal. It is like that.

  In this example, the listener at the center seat has a lateral orientation effect at low frequencies, the listener at the right seat has lateral orientation effects in the mid range, and the listener at the left seat has side effects in the high range. The phase of the surround signal is controlled so that a localization effect is obtained. As a result, each listener can experience the lateral localization effect at each seat position.

—Example 3—
Next, an embodiment of the signal processing unit when the listener is present in the center seat and the right seat will be described with reference to FIGS. 9 and 10. FIG. 9 is a configuration diagram showing the flow of the surround signal for the left speaker input of the signal processing unit in the third embodiment, and FIG. 10 is a configuration diagram showing the flow of the surround signal for the right speaker input of the signal processing unit in the third embodiment. is there.

  In this embodiment, the surround signal to be input to the surround speaker is divided into a low band, a mid band, and a high band, a central seat is allocated to the low band and the high band, a right seat is allocated to the mid band, Lateral localization processing is performed for listeners assigned to each seat in the band.

  In the signal processing unit 200 of the present embodiment, first, as shown in FIG. 9, the left surround signal SL to be output to the left surround speaker is a left speaker input surround signal SLL and a right speaker input surround signal SLR. And then branch off.

  The left speaker input surround signal SLL is divided into a low frequency band, a mid frequency band and a high frequency band by LPF, BPF, and HPF, and then the frequency band is flattened and the sound pressure level is equalized. The level of the surround signal corresponding to the midrange is adjusted. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SLR for right speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by an all-pass filter, and then low, mid, and low by LPF, BPF, and HPF. The frequency band is divided into high frequencies, and a delay and attenuation process is performed so that the sound image is localized to the side of the listener in the right seat with respect to the surround signal corresponding to the middle frequency. Note that the level of the surround signal corresponding to the mid-range is adjusted so that the band is flat and the sound pressure level is uniform. Then, the band-divided surround signals are combined and output.

  In the signal processing unit 200, as shown in FIG. 10, the surround signal SR to be input to the right surround speaker is branched into a surround signal SRR for right speaker input and a surround signal SRL for left speaker input. The

  The surround signal SRR for the right speaker input is divided by the LPF, BPF, and HPF into the low frequency, mid frequency, and high frequency, and then the right seat's surround signal SRR Delay and attenuation processing is performed so that the sound image is localized to the side. Note that the level of the surround signal corresponding to the mid-range is adjusted so that the band is flat and the sound pressure level is uniform. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SRL for the left speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by the all-pass filter, and then the low-pass, mid-pass, LPF, BPF, and HPF The level of the surround signal corresponding to the mid-range is adjusted so that the frequency band is divided into the high range, the band is flattened, and the sound pressure level is equalized. Then, the band-divided surround signals are combined and output.

  The right speaker input surround signals SLR and SRR are combined and input to the FR speaker as a right surround signal, and the left speaker input surround signals SLL and SRL are combined and input to the FL speaker as a left surround signal. It is like that.

  In this embodiment, considering that it is effective to assign a central seat for the low range and the high range and a right seat or a left seat for the mid range, it is effective for the listener at the central seat to A surround effect is obtained, and the phase of the surround signal is controlled so that a listener at the right seat can obtain a lateral orientation effect in the mid range. Thereby, each listener can fully experience the lateral localization effect at each seat position.

—Example 4—
Next, an embodiment of the signal processing unit when a listener is present in each of the central seat, the right seat, and the left seat will be described with reference to FIGS. 11 and 12. FIG. 11 is a block diagram showing the flow of the surround signal for the left speaker input of the signal processing unit in the fourth embodiment, and FIG. 12 is a block diagram showing the flow of the surround signal for the right speaker input of the signal processing unit in the fourth embodiment. is there.

  In this embodiment, a surround signal to be input to a surround speaker is divided into a low band, two mid bands, and a high band, and a central seat is allocated to the low band and the high band, and a right seat is allocated to the two mid bands. And the left seat are assigned to each side, and the lateral localization process is performed on the listeners assigned to the respective seats in each band. In this embodiment, the middle region with the lower frequency band is assigned to the right seat, and the middle region with the higher frequency band is assigned to the left seat.

  In the signal processing unit 200 of the present embodiment, first, as shown in FIG. 11, the left surround signal SL to be output to the left surround speaker is a left speaker input surround signal SLL and a right speaker input surround signal SLR. And then branch off.

  The left speaker input surround signal SLL is divided by the LPF, BPF1, BPF2, and HPF into the low band, the middle band consisting of two frequency bands, and the high band after the frequency band is divided into the high band. The surround signal corresponding to is delayed and attenuated so that the sound image is localized to the side of the listener in the left seat. Note that the levels of the surround signals corresponding to the two middle bands having different frequency bands are adjusted so that the bands are flat and the sound pressure levels are uniform. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SLR for right speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by an all-pass filter, and then low frequency, 2 by LPF, BPF1 The frequency band is divided into a middle band and a high band consisting of two frequency bands, and the delay and the sound image are localized to the side of the right seat listener with respect to the surround signal corresponding to the middle band on the lower frequency band side. It is attenuated. Note that the levels of the surround signals corresponding to the two middle bands having different frequency bands are adjusted so that the bands are flat and the sound pressure levels are uniform. Then, the band-divided surround signals are combined and output.

  In the signal processing unit 200, as shown in FIG. 12, the surround signal SR to be input to the right surround speaker is branched into a surround signal SRR for right speaker input and a surround signal SRL for left speaker input. The

  The right speaker input surround signal SRR is divided into a low frequency band, a middle frequency band consisting of two frequency bands, and a high frequency band by LPF, BPF1, BPF2, and HPF. Is delayed and attenuated so that the sound image is localized to the side of the listener in the right seat. Note that the levels of the surround signals corresponding to the two middle bands having different frequency bands are adjusted so that the bands are flat and the sound pressure levels are uniform. Then, the band-divided surround signals are combined and output.

  On the other hand, the surround signal SRL for the left speaker input is subjected to phase control processing so that the sound image is localized to the side of the listener at the center seat by the all-pass filter, and then the low-frequency, 2 The frequency band is divided into a middle band and a high band consisting of two frequency bands, and a delay and a sound image are localized to the side of the left seat listener with respect to the surround signal corresponding to the middle band on the higher frequency band side. Processed with decay. Note that the levels of the surround signals corresponding to the two middle bands having different frequency bands are adjusted so that the bands are flat and the sound pressure levels are uniform. Then, the band-divided surround signals are combined and output.

  The right speaker input surround signals SLR and SRR are combined and input to the FR speaker as a right surround signal, and the left speaker input surround signals SLL and SRL are combined and input to the FL speaker as a left surround signal. It is like that.

  In this example, it is effective to assign a central seat for the low range and high range, and a right seat or a left seat for the middle range. It is possible to obtain a localization effect, so that the right seat listener can obtain a lateral localization effect in the middle range where the frequency is high, and the left seat listener can obtain a lateral localization effect in the mid range where the frequency is low. The phase of the surround signal is controlled. Thereby, each listener can fully experience the lateral localization effect at each seat position.

  In addition, this application is not restricted to embodiment mentioned above, It can implement with a various form. For example, the width of the middle band when dividing the frequency band can be freely set as long as the left and right energy balance is adjusted, and this band is divided more finely than the embodiment by the octave band filter, and the right seat and the left Seats may be assigned alternately. In addition, since the localization of the sound image for the listeners in the right seat and the left seat differs considerably depending on the position where the listener sits, the delay and attenuation processing may be set freely on the listener side. The sound image localization processing apparatus described in this embodiment can be applied to a home theater system, a thin television such as a PDP, a personal surround system such as a PC and a portable DVD.

[Second Embodiment]
[Example in which the listener does not exist at the same distance (central seat) from the left and right speakers]
In the first to fourth embodiments described above, the case where the listener is at the center (exists) of the left and right speakers has been described. However, in the following Examples 5 to 7, a case where two listeners are not in the central seat will be described. Hereinafter, the case where the listener is not at the center of the left and right speakers will be described with reference to FIGS.

  FIG. 13 is a block diagram illustrating the hardware configuration of the surround system necessary for implementing the fifth to seventh embodiments in addition to the configuration of the surround system for implementing the first to fourth embodiments.

  The surround system in FIG. 13 includes a system control unit 125, an amplifier 140, an amplifier 141, a speaker FL (left speaker), a speaker FR (right speaker), a microphone 142, and an input device 143.

  The system control unit 125 includes a test signal generation unit 126, an analysis unit 127, a memory 128, and a control unit 129.

  The test signal generator 126 is a part that generates a test signal SG1 for measuring the arrival time of the music sound from the microphone 142 to each speaker. Test signal SG1 is amplified by amplifier 140 and emitted from speaker FL or speaker FR. Further, the test signal generation unit 126 outputs a test information signal SG2 including information such as transmission timing (transmission time) regarding the test signal SG1 to the analysis unit 127.

  The analysis unit 127 includes the test information signal SG2 generated by the test signal generation unit 126, the reception signal SG3 input via the amplifier 141 from the microphone 142 that has received the sound emitted from the speaker FL or the speaker FR, Are compared, and distance calculation (distance measurement) from the speaker FL and the speaker FR to the microphone 142 is performed. The calculation result is transmitted to the signal processing unit 200 illustrated in FIG. 1 via an internal bus or a signal line connected from the outside.

  The memory 128 stores a progress or calculation result in the calculation of the analysis unit 127.

  The control unit 129 controls the test signal generation unit 126 to generate the test signal SG1 and the test information signal SG2, and controls the analysis unit 127 to calculate the distance from the speaker FL and the speaker FR to the microphone 142, Control is performed based on information input to the input device 143.

  The microphone 142 receives the test sound emitted from the speaker FL or the speaker FR as described above, and transmits the received test sound to the amplifier 141 (the output signal of the amplifier 141 is referred to as the reception signal SG3 as described above). .)

  The input device 143 is used for instructing the start of measurement of the distance from the speaker FL or the speaker FR to the microphone 142, the end instruction, and the input instruction for the installation distance between the speaker FL and the speaker FR.

  Although the test signal generation unit 126, the analysis unit 127, the memory 128, and the control unit 129 in FIG. 13 are provided in the system control unit 125 in FIG. 1, the present invention is not limited to this, and the system control A configuration provided outside the portion 125 may also be adopted. Further, the input device 143 can be shared with the operation unit 124 in FIG. Furthermore, the speaker FL and the speaker FR may be configured to be shared with or built in the speaker 132 in FIG.

  Further, the amplifier 140 may be shared with the power amplifier 123FL in FIG. 1 or may be built in the power amplifier 123FL. Further, the amplifier 141 may be shared with the power amplifier 123FR in FIG. 1 or built in the power amplifier 123FR.

  Next, referring to FIGS. 14 and 15, when the microphone 142 is installed at a position where the listener listens to the music sound emitted from the speaker FL and the speaker FR, the speaker FL and the speaker FR to the microphone 142 are used. A processing operation for calculating the distance will be described with reference to a flowchart.

  In step S <b> 1, the listener inputs the distance between the speakers FL and FR from the input device 143.

  In step S <b> 2, the listener installs the microphone 142 at a position to listen to the music sound emitted from the speaker FL and the speaker FR.

  In step S <b> 3, the listener inputs instruction information for measuring the distance between the speaker FL and the speaker FR and the microphone 142 to the input device 143. The instruction information is transmitted to the control unit 129, and the control unit 129 controls the test signal generation unit 126 to emit the test signal SG1 from the speaker FL and the speaker FR. In addition, control is performed so that a test information signal SG2 including timing information for generating the test signal SG1 is output from the test signal generator 126 to the analyzer 127. The microphone 142 receives the sound emitted from each speaker (the test signal SG1 is emitted from the speaker FL and the speaker FR at different timings), and the reception signal SG3 output from the amplifier 141 is the analysis unit 127. Is input.

  In step S4, the analysis unit 127 receives the test information signal SG2 generated by the test signal generation unit 126 and the input from the microphone 142 that has received the sound emitted from the speaker FL or the speaker FR via the amplifier 141. The signal SG3 is compared, and the distance from the speaker FL and the speaker FR to the microphone 142 is calculated.

  In step S <b> 5, the control unit 129 controls the analysis unit 127 to store the distance information from each speaker calculated in step S <b> 4 to the microphone 142 in the memory 128.

  In step S <b> 6, the control unit 129 determines whether or not the listener has input measurement end instruction information to the input device 143. If the control unit 129 determines that measurement end instruction information has been input (step S6: Yes), the process proceeds to step S8. If the control unit 129 determines that measurement end instruction information has not been input (step S6: Yes), the process proceeds to step S8. Next, the process proceeds to step S7.

  In step S7, when the listener listens to the music sound emitted from the speaker FL and the speaker FR at another seat at the same time, the microphone 142 is placed at another seat position where the other listener listens. Is installed.

  In step S8, the system control unit 125 determines the position at which the microphone 142 is installed from the speaker FL and the speaker FR calculated in step S4 with respect to the memory 128 (the music sound emitted from the speaker FL and the speaker FR by the listener). The result value obtained by calculating the distance to the listening position is controlled so as to be output from the memory 128, and used for calculation in each step after step S9.

  In step S9, when the listener listens to the music sound emitted from the speaker FL and the speaker FR, the time alignment value of the music sound emitted from the speaker FL and the speaker FR at the position where each listener listens ( The time difference between the sounds emitted from the speaker FL and the speaker FR at the listening position of the listener is calculated, and the delay value is calculated when a delay of the difference is added to a signal that arrives earlier. Further, the listening position can be determined from the distance from each speaker calculated from the measured data to the listening position and the speaker interval that the listener first inputs in step S1. The distance from each speaker to the listening position is calculated by multiplying the arrival time of the signal by the speed of sound.

  In step S10, the system control unit 125 determines whether the positions at which the two listeners listen to the music sound are on opposite sides from the center of the distance between the speaker FL and the speaker FR (one listener listens to each speaker). Or if the other listener is listening at a position approaching the speaker FR from the center position between the speakers (step S10: YES)) or not (When two listeners listen at a position approaching the speaker FL side or the speaker FR side from the central position between the speakers. (Step S10: NO)). If the positions at which the two listeners listen to the music sound are on opposite sides from the center of the distance between the speaker FL and the speaker FR (step S10: YES), the process proceeds to step S11. If the position where the two listeners listen to the music sound is on the same side from the center of the distance between the speaker FL and the speaker FR (step S10: NO), the process proceeds to step S12. Next, the process proceeds to step S11.

  In step S <b> 11, the system control unit 125 distributes the band of the music sound emitted from each speaker described in the fifth embodiment.

  In step S15, the system control unit 125 performs processing described in the fifth embodiment.

  In step S13, the system control unit 125 determines whether or not the two listeners are both on the speaker FL side from the center of the distance between the speaker FL and the speaker FR. When the two listeners are both on the speaker FL side from the center of the distance between the speaker FL and the speaker FR (step S13: YES), the process proceeds to step S14. When the two listeners are both on the speaker FR side from the center of the distance between the speaker FL and the speaker FR (step S13: NO), the process proceeds to step S16. Next, the process proceeds to step S14.

  In step S14, the system control unit 125 distributes the band of the music sound emitted from each speaker described in the sixth embodiment.

  In step S15, the system control unit 125 performs processing described in the sixth embodiment. Next, the process proceeds to step S16.

  In step S <b> 16, the system control unit 125 distributes the band of the music sound emitted from each speaker described in the seventh embodiment.

  In step S17, the system control unit 125 performs the process described in the seventh embodiment.

  Next, Examples 5 to 7 will be described in order.

-Example 5
The frequency of the sound emitted from the speakers when the two listeners are listening to the music sound emitted from the speakers on the opposite side from the center of the distance between the speakers FL and FR. The division will be described with reference to FIGS. 16 and 17. FIG. 16 is a diagram illustrating an example of a positional relationship between the speaker FL and the speaker FR and a method of distributing the frequency of the music sound emitted from the speaker FL and the speaker FR. FIG. 17 is a diagram illustrating a method for processing the left surround signal SL_in and a method for processing the right surround signal SR_in.

  First, an example of a method for distributing the frequency of music emitted from the speaker FL and the speaker FR will be described with reference to FIG.

  FIG. 16A is a diagram illustrating the positional relationship between the position of the speaker and the listener in the fifth embodiment.

  In FIG. 16A, the listener A emits sound from the speaker FL and the speaker FR at a position close to the speaker FL (speaker FL side) from the center line position CLR of the distance between the speaker FL and the speaker FR. It shows that he is trying to listen to the music. In addition, the listener B listens to the music sound emitted from the speaker FL and the speaker FR at a position close to the speaker FR (speaker FR side) from the center line position CLR of the distance between the speaker FL and the speaker FR. It is shown that.

  FIG. 16B is a diagram illustrating an example of a frequency distribution method for the left surround signal SL_in and the right surround signal SR_in according to the fifth embodiment.

  As described above, the effective frequency band for the technology of the present application is approximately 500 Hz to approximately 2000 Hz. Accordingly, it is most effective to set the acoustic center of 1000 Hz as a cut-off frequency for band division (frequency division), and the frequency division method in this frequency band will be described below.

  In the lateral localization process, when the seat that the user listens to is asymmetric from the center position of the distance between the two speakers, the effect of the control signal described in the first embodiment may be weak depending on the band. This is because when the listener who listens to the music sound approaches one speaker, the path difference of the control signal emitted from the speaker changes between the left and right ears of each person who is the listener.

  Specifically, the path difference of the control signal emitted from the speaker that the listener has approached becomes small between the ears of the listener. When the path difference between the listener's ears is reduced, the phase difference between the listener's ears is also reduced. When the phase difference between the listener's ears becomes small, the sound pressure level difference between the listener's ears also becomes small, and a sufficient sound pressure level difference between the ears does not occur. Therefore, the lateral localization effect is also reduced, making it difficult to obtain a sufficient surround effect. This phenomenon is particularly noticeable in a low frequency band with a long wavelength.

  In general, in a low frequency range, a sound image is easily localized on the left side at a position to the left of the center between the speakers, and a sound image is not easily localized on the right side. Similarly, at a position to the right of the center between the speakers, it is easy to localize the sound image on the right side, and it is difficult to localize the sound image on the left side.

  Therefore, it is necessary to output as low a low frequency control signal as possible from a speaker close to the listener (thus, to output a low frequency surround signal as much as possible from a speaker close to the listener). . Conversely, a high frequency control signal is not output as much as possible from a speaker far from the listener (thus, a high frequency surround signal is output as much as possible from a speaker far from the listener). is necessary.

  Here, the low frequency means a frequency from about 500 Hz to about 1000 Hz, and the high frequency means a frequency from about 1000 Hz to about 2000 Hz. However, the present application does not distinguish between the high frequency and the low frequency only for these frequencies, and an arbitrary frequency can be set to the high frequency and the low frequency. In particular, in the present embodiment, the frequency for distinguishing between the high frequency and the low frequency is approximately 1000 Hz. However, the frequency is not limited to approximately 1000 Hz, and an arbitrary value from approximately 500 Hz to approximately 2000 Hz is set as the high frequency. And a low frequency can be set as a frequency. These can also be applied to other embodiments.

  Also, the cutoff frequency when assigning the frequency (band) is varied between approximately 500 Hz and approximately 2000 Hz, which is the frequency at which the front surround effect is most obtained, depending on the distance from the center position between the speakers of the listener. Also good. For example, the position of the listener facing the speaker is approximately 500 Hz, and if the listener is at the center position between the speakers, the frequency is approximately 2000 Hz. If the listener is between them (position between the speakers) The center frequency for dividing the frequency may be varied between about 500 Hz and about 2000 Hz depending on the distance from the speaker. These can also be applied in other embodiments.

  Next, in the fifth embodiment of FIG. 16B, the left surround signal input signal in the surround signal will be described as the left surround signal SL_in, and the right surround signal input signal in the surround signal will be described as the right surround signal SR_in.

  In FIG. 16A, since the listener A is going to listen to the music sound on the left side from the center line position CLR, the listener A starts from the left speaker FL when the listener A faces the speaker. Is closer than the distance from the right speaker FR to the listener A. Therefore, as described above, the left surround signal SL_in from the speaker FL closer to the listener A is set to the low frequency, and the right surround signal SR_in from the speaker FR farther from the listener A is set to the high frequency. Set to frequency. This is shown in FIG. 16 (b).

  In FIG. 16 (a), the listener B is about to listen to the music sound on the right side from the center line position CLR, so that the listener B listens from the right speaker FR when the listener B faces the speaker. The distance to the person B is closer than the distance from the left speaker FL to the listener B. Therefore, the right surround signal SR_in from the speaker FR closer to the listener B is set to a low frequency, and the left surround signal SL_in from the speaker FL farther from the listener B is set to a high frequency. This is shown in FIG. 16 (b).

  Next, a method for processing the left surround signal SL_in will be described with reference to FIG.

  The left surround signal SL_in is first subjected to front surround processing.

  In the front surround processing, when the surround signal SL_inL output from the left speaker (speaker FL) is generated, the processing including processing such as level correction and attenuation processing described in the first to fourth embodiments is referred to as front surround processing. Become.

  When the control signal SL_inR output from the right speaker (speaker FR) is generated, the processing including the phase control processing, level correction, attenuation processing, and the like described in the first to fourth embodiments is referred to as front surround processing. Become.

  The surround signal SL_inL generated in the front surround processing is subjected to band division processing. A low frequency is assigned to the listener A for the listener A, and a surround signal SL_inLA for A is generated. A high frequency is assigned to the listener B for the listener B, and the surround signal SL_inLB for B is assigned. Is generated.

  Next, the A surround signal SL_inLA is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)), and is sent to the left speaker (speaker FL). As an input signal SL_out, it is output from the time alignment processing unit for A (listener A).

  The B surround signal SL_inLB is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)) and input to the left speaker (speaker FL). The signal SL_out is output from the time alignment processing unit for B (listener B).

  Further, the control signal SL_inR generated in the front surround processing is also subjected to band division processing. A low frequency is assigned to the listener A for the listener A and a control signal SL_inRA for A is generated. A high frequency is assigned to the listener B for the listener B, and the control signal SL_inRB for B is assigned. Is generated.

  Next, the A control signal SL_inRA is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)), and is sent to the right speaker (speaker FR). As an input signal SR_out, it is output from the time alignment processing unit for A (listener A).

  Further, the B control signal SL_inRB is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)) and input to the right speaker (speaker FR). The signal SR_out is output from the time alignment processing unit for B (listener B).

  Next, a processing method for the right surround signal SR_in will be described with reference to FIG.

  The right surround signal SR_in is first subjected to front surround processing.

  In the front surround processing, when the control signal SR_inL output from the left speaker (speaker FL) is generated, processing including processing such as phase control processing, level correction, and attenuation processing described in the first to fourth embodiments is performed. Front surround processing.

  When the surround signal SR_inR output from the right speaker (speaker FR) is generated, the processing including the level correction and attenuation processing described in the first to fourth embodiments is the front surround processing.

  The control signal SR_inL generated in the front surround processing is subjected to band division processing. A low frequency is assigned to the listener B for the listener B, and a B control signal SR_inLB is generated. A high frequency is assigned to the listener A for the listener A, and the control signal SR_inLA for A is assigned. Is generated.

  Next, the B control signal SR_inLB is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)), and is sent to the left speaker (speaker FL). As an input signal SL_out, it is output from the time alignment processing unit for B (listener B).

  The A control signal SR_inLA is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)) and input to the left speaker (speaker FL). The signal SL_out is output from the time alignment processing unit for A (listener A).

  Further, the surround signal SR_inR generated in the front surround processing is subjected to band division processing. A low frequency is assigned to the listener B for the listener B, and a surround signal SR_inRB for B is generated. A high frequency is assigned to the listener A for the listener A, and the surround signal SR_inRA for A is assigned. Is generated.

  Next, the B surround signal SR_inRB is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)), and is sent to the right speaker (speaker FR). As an input signal SR_out, it is output from the time alignment processing unit for B (listener B).

  Further, the A surround signal SR_inRA is delayed by a time determined based on the time alignment value generated in step S9 in FIG. 15 (time delay processing (time alignment processing)) and input to the right speaker (speaker FR). The signal SR_out is output from the time alignment processing unit for A (listener A).

  In this way, at the position of the listener A that is close to the left speaker (speaker FL), it is easy to localize the sound image to the left rear of the listener A at the low frequency, and to the right rear of the listener A at the high frequency. It is easy to localize the sound image. That is, it is effective to perform frequency band division that does not output a control signal at a low frequency as much as possible from a nearby speaker (speaker FL).

  Accordingly, by assigning a low frequency (band) as a surround signal to the speaker FL for the listener A and assigning a high frequency (band) as a control signal to the speaker FR, the listener A has a front surround effect. You can fully experience it.

  Also, by assigning a low frequency (band) as a surround signal to the speaker FR for the listener B and assigning a high frequency (band) as a control signal to the speaker FL, the listener B has a front surround effect. You can fully experience it.

-Example 6-
Next, each speaker when the two listeners are at the speaker FL side from the center of the distance between the speaker FL and the speaker FR at the position where the two listeners listen to the music sound emitted from the speaker. The frequency division of the sound emitted from will be described with reference to FIG. 18 and FIG. FIG. 18 is a diagram illustrating an example of a positional relationship between the speaker FL, the speaker FR, the listener A, and the listener B, and a method for distributing the frequency of the music sound emitted from the speaker FL and the speaker FR. FIG. 19 is a diagram illustrating a method for processing the left surround signal SL_in and a method for processing the right surround signal SR_in.

  First, an example of a method for distributing the frequencies of music sounds emitted from the speakers FL and FR will be described with reference to FIG.

  FIG. 18A is a diagram illustrating the positional relationship between the position of the speaker and the listener in the sixth embodiment.

  Both the listener A and the listener B are located on the left in FIG. 18A from the center line position CLR. In this case, in either seat, the sound image tends to be localized to the left side at a low frequency and the sound image tends to be localized to the right side at a high frequency. Therefore, when the frequency allocation (frequency dividing method) described in the fifth embodiment is performed, the lateral localization effect is concentrated on the listener A, and it becomes difficult for the listener B to obtain a sufficient lateral localization effect. End up. Therefore, in the sixth embodiment, in order to prevent the concentration of the lateral localization effect on the listener A or the listener B, the listening at a position closer to the center line position CLR (the distance from both speakers is the same). A low frequency is assigned to the listener to prevent concentration of the lateral localization effect on one of the listeners.

  In FIG. 18A, since the listener A is going to listen to the music sound on the left side from the center line position CLR, the listener A starts from the left speaker FL when the listener A faces the speaker. Is closer than the distance from the right speaker FR to the listener A. Also, since the listener B is also trying to listen to the music sound on the left side from the center line position CLR, the distance from the listener B to the listener B on the left speaker FL when the listener B faces the speaker is It is closer than the distance from the right speaker FR to the listener B.

  Here, paying attention to the positional relationship between the listener A and the listener B, the listener B is closer to the center line position CLR than the listener A. Therefore, as described above, the effect that the listener A who is far from the center line position CLR is localized to the side at a lower frequency than the listener B is reduced. Therefore, the surround signal at the low frequency from the speaker FL and the speaker FR is assigned to the listener B, and the surround signal at the high frequency from the speaker FL and the speaker FR is assigned to the listener A, thereby efficiently listening to the listener A and the listener. A lateral orientation effect can be exerted on the person B.

  Therefore, as shown in FIG. 18B, the surround signal SL from the speaker FL and the left surround signal SR input to the speaker FR are applied to the listener B closer to the center line position CLR. Set to frequency. Also, for the listener A who is farther from the center line position CLR, the lateral localization effect at the low frequency is reduced, so that the surround signal SL from the speaker FL and the left input to the speaker FR are reduced. The surround signal SR is set to a high frequency.

  Next, a method for processing the left surround signal SL_in will be described with reference to FIG. A description of the same processing as in FIG.

  A process different from FIG. 17A is a band division process. A high frequency is assigned to the A surround signal SL_inLA in the left surround signal SL_in, and a low frequency is assigned to the B surround signal SL_inLB. Further, a high frequency is assigned to the A control signal SL_inRA in the control signal SL_inR, and a low frequency is assigned to the B control signal SL_inRB. Further, the delay time when performing the time alignment process for A differs depending on the position of the listener A. Similarly, the delay time when performing the time alignment process for B differs depending on the position of the listener B.

  Next, FIG. 19B illustrates the processing method of the right surround signal SR_in, but the same processing as FIG. 17B except for the time alignment processing to A and the time alignment processing to B. Is doing. The delay time when performing the time alignment process for A varies depending on the position of the listener A. Similarly, the delay time when performing the time alignment process for B varies depending on the position of the listener B.

  Thus, at the position of the listener A who is far from the center line position CLR of both speakers, it is difficult to localize the sound image at a low frequency. Further, it is easy to localize the sound image at the position of the listener A at a high frequency.

  Therefore, by assigning a high frequency (band) as a surround signal to the speaker FL and the speaker FR and assigning a low frequency (band) as a control signal to the speaker FR and the speaker FR to the listener A, the listener A can fully experience the front surround effect.

  Also, by assigning a low frequency (band) as a surround signal to the speaker FL and the speaker FR for the listener B and assigning a high frequency (band) as a control signal to the speaker FL and the speaker FR, the listener B can fully experience the front surround effect.

-Example 7-
Next, each position when the two listeners are at the speaker FR side from the center position of the distance between the speaker FL and the speaker FR is the position at which the two listeners listen to the music sound emitted from the speaker. A frequency division method for sound emitted from the speaker will be described with reference to FIGS. 20 and 21. FIG. FIG. 20 is a diagram illustrating an example of a positional relationship among the speaker FL, the speaker FR, the listener A, and the listener B, and a method for distributing the frequency of the music sound emitted from the speaker FL and the speaker FR. FIG. 21 is a diagram illustrating a method for processing the left surround signal SL_in and a method for processing the right surround signal SR_in.

  First, an example of a method for distributing the frequencies of music sounds emitted from the speakers FL and FR will be described with reference to FIG.

  FIG. 20A is a diagram illustrating the positional relationship between the position of the speaker and the listener in the seventh embodiment.

  In FIG. 20A, since the listener A is going to listen to the music sound on the right side from the center line position CLR, the listener A starts from the left speaker FL when the listener A faces the speaker. Is farther than the distance from the right speaker FR to the listener A. Also, since the listener B is about to listen to the music sound on the right side from the center line position CLR, the distance from the listener B to the listener B on the left speaker FL when the listener B faces the speaker is It is farther than the distance from the right speaker FR to the listener B.

  When attention is paid to the positional relationship between the listener A and the listener B, the listener A is closer to the center line position CLR than the listener B. Therefore, as described above, the effect that the listener B who is far from the center line position CLR is localized to the side at a lower frequency than the listener B is reduced. Therefore, the surround signal at the low frequency from the speaker FL and the speaker FR is assigned to the listener A, and the surround signal at the high frequency from the speaker FL and the speaker FR is assigned to the listener B, thereby efficiently listening to the listener A and the listener. A lateral orientation effect can be exerted on the person B.

  Therefore, as shown in FIG. 20B, the surround signal SL from the speaker FL and the left surround signal SR input to the speaker FR are reduced to the listener A closer to the center line position CLR. Set to frequency. Further, for the listener B farther from the center line position CLR, the lateral localization effect at the low frequency is reduced, so that the surround signal SL from the speaker FL and the left input to the speaker FR are reduced. The surround signal SR is set to a high frequency.

  Next, FIG. 21A illustrates the processing method of the left surround signal SL_in, but the same processing as FIG. 17A except for the time alignment processing to A and the time alignment processing to B. Is doing. The delay time when performing the time alignment process for A varies depending on the position of the listener A. Similarly, the delay time when performing the time alignment process for B varies depending on the position of the listener B.

  Next, a processing method for the right surround signal SR_in will be described with reference to FIG. A description of the same processing as in FIG.

  A process different from FIG. 17B is a band division process. A low frequency is assigned to the A surround signal SR_inRA in the right surround signal SR_inR, and a high frequency is assigned to the B surround signal SR_inRB. Further, a low frequency is assigned to the A control signal SR_inLA in the control signal SR_inL, and a high frequency is assigned to the B control signal SR_inLB. Further, the delay time when performing the time alignment process for A differs depending on the position of the listener A. Similarly, the delay time when performing the time alignment process for B differs depending on the position of the listener B.

  Thus, at the position of the listener B who is far from the center line position CLR of both speakers, it is difficult to localize the sound image at a low frequency. Further, it is easy to localize the sound image at the position of the listener B at the high frequency.

  Therefore, by assigning a high frequency (band) as a surround signal to the speaker FL and the speaker FR and assigning a low frequency (band) as a control signal to the speaker FR and the speaker FR to the listener B, the listener B can fully experience the front surround effect.

  Further, by assigning a low frequency (band) as a surround signal to the speaker FL and the speaker FR for the listener A and assigning a high frequency (band) as a control signal to the speaker FL and the speaker FR, the listener A can fully experience the front surround effect.

[Third embodiment]
[Another embodiment with 3 listeners]
Next, when there are three listeners, a third embodiment that performs frequency band division different from the first embodiment will be described with reference to FIG.

  FIG. 22A is a diagram showing a positional relationship between the speaker FL and the speaker FR, and the listener A, the listener B, and the listener C. The listener B does not need to be at the same distance from the speaker FL and the speaker FR (the distance between the speaker FL and the speaker FR and the listener B may be the same distance or may be the same distance). .) The listener A listens on the side close to the speaker FL, and the listener C listens on the side close to the speaker FR.

  FIG. 22B is a diagram showing a frequency distribution method for the left surround signal SL and the right surround signal SR for the listeners A, B, and C.

  In the present embodiment, the frequency (band) from approximately 500 Hz to approximately 2000 Hz is divided into three equal parts. Then, the central portion (intermediate frequency band) of the frequency is assigned to the listener B in the center of the listener. Further, the low frequency of the left surround signal SL is assigned to the listener A who is close to the left speaker FL, and the high frequency is assigned to the right speaker FR which is far from the listener A. assign. Further, the low frequency of the right surround signal SR is assigned to the listener C located near the right speaker FR, and the high frequency is assigned to the left speaker FL located far from the listener C. assign.

  By assigning the frequency of the surround signal in this way, three listeners can feel the lateral localization effect while compensating for the superiority or inferiority of the lateral localization effect depending on the frequency, and constitute a more realistic surround speaker. It becomes possible to do.

  Further, according to the present invention, the phase of the surround signal is controlled so that the listener at the center seat can obtain a lateral localization effect at low frequencies, and the listener at the right seat can obtain a lateral localization effect at high frequencies. As a result, each listener can experience the lateral localization effect at each seat position.

  Furthermore, the present invention provides a lateral localization effect in the low frequency range for the listener at the center seat, a lateral localization effect in the mid frequency range for the listener in the right seat, and a lateral localization effect in the high frequency range for the listener in the left seat. The phase of the surround signal is controlled so that a localization effect is obtained. As a result, each listener can experience the lateral localization effect at each seat position.

  Furthermore, the present invention considers that it is effective to assign a central seat for the low and high ranges and a right seat or a left seat for the middle range, so that the listener at the central seat can be seen laterally in the low and high ranges. A surround effect is obtained, and the phase of the surround signal is controlled so that a listener at the right seat can obtain a lateral orientation effect in the mid range. Thereby, each listener can fully experience the lateral localization effect at each seat position.

  Furthermore, the present invention considers that it is effective to assign a central seat for the low and high ranges and a right seat or a left seat for the middle range, so that the listener at the central seat can be seen laterally in the low and high ranges. It is possible to obtain a localization effect, so that the right seat listener can obtain a lateral localization effect in the middle range where the frequency is high, and the left seat listener can obtain a lateral localization effect in the mid range where the frequency is low. The phase of the surround signal is controlled. Thereby, each listener can fully experience the lateral localization effect at each seat position.

  Furthermore, according to the present invention, at the position of the listener A who is close to the left speaker (speaker FL), the sound image can be easily localized to the left rear of the listener A at the low frequency, and the listener A at the high frequency is It is easy to localize the sound image to the right rear. That is, it is effective to perform frequency band division that does not output a control signal at a low frequency as much as possible from a nearby speaker (speaker FL).

  Accordingly, by assigning a low frequency (band) as a surround signal to the speaker FL for the listener A and assigning a high frequency (band) as a control signal to the speaker FR, the listener A has a front surround effect. You can fully experience it.

  Further, according to the present invention, a high frequency (band) is assigned as a surround signal to the speaker FL and the speaker FR for the listener A, and a low frequency (band) is assigned to the speaker FR and the speaker FR as a control signal. By assigning, the listener A can fully experience the front surround effect.

  Also, by assigning a low frequency (band) as a surround signal to the speaker FL and the speaker FR for the listener B and assigning a high frequency (band) as a control signal to the speaker FL and the speaker FR, the listener B can fully experience the front surround effect.

  Furthermore, according to the present invention, a high frequency (band) is assigned as a surround signal to the speaker FL and the speaker FR for the listener B, and a low frequency (band) is assigned to the speaker FR and the speaker FR as a control signal. By assigning, the listener B can fully experience the front surround effect.

  Further, by assigning a low frequency (band) as a surround signal to the speaker FL and the speaker FR for the listener A and assigning a high frequency (band) as a control signal to the speaker FL and the speaker FR, the listener A can fully experience the front surround effect.

  Further, according to the present invention, by assigning the frequency of the surround signal to a plurality of people, three or more listeners can obtain a more lateral localization effect while compensating for the superiority or inferiority of the lateral localization effect due to the frequency. A surround speaker that can be perceived and has a more realistic feeling can be configured.

  In the embodiments described so far, the cutoff frequency has been assigned the same frequency to the left surround signal SL and the right surround signal SL. However, the present application is not limited to this, and the left surround signal SL is not limited thereto. The cut-off frequency of the right surround signal SL may be different from the cut-off frequency of the right surround signal SL. It is also possible to provide a frequency band that is not assigned to the listener for each surround signal (SL, SR).

  In addition, the present application is not limited to the number of listeners, and provides a front surround speaker that is more realistic for each listener by appropriately dividing the frequency based on the position of the listener and the position of the speaker. Is possible.

  For example, a technique can be used in which a low frequency is assigned to a listener closer to each speaker, and a higher frequency is assigned to a listener away from the speaker. In this case, the frequency band to be allocated can be equally divided by the number of listeners or appropriately divided.

  In addition, this application is not restricted to embodiment mentioned above, It can implement with a various form. For example, the width of the middle band when dividing the frequency band can be freely set as long as the left and right energy balance is adjusted, and this band is divided more finely than the embodiment by the octave band filter, and the right seat and the left Seats may be assigned alternately. In addition, since the localization of the sound image for the listeners in the right seat and the left seat differs considerably depending on the position where the listener sits, the delay and attenuation processing may be set freely on the listener side. The sound image localization processing apparatus described in this embodiment can be applied to a home theater system, a thin television such as a PDP, a personal surround system such as a PC and a portable DVD.

  The operation procedure in FIGS. 1 to 22 is recorded in advance on a recording medium such as a hard disk or recorded in advance via a network such as the Internet, and is read and executed by a general-purpose microcomputer or the like. Accordingly, it is possible to cause the general-purpose microcomputer or the like to function as the CPU according to the embodiment.

It is a block diagram which shows the structure of the surround system of this embodiment. It is a figure which shows an example for demonstrating the relationship between arrangement | positioning of each speaker, and a listener's seat position. It is explanatory drawing of the lateral localization process in a signal processing part. It is an example which shows the relationship between the installation position of a speaker, and a listener's seat position. It is a block diagram which shows the flow of the surround signal for left speaker input of the signal processing part in the present Example 1. It is a block diagram which shows the flow of the surround signal for right speaker input of the signal processing part in the present Example 1. It is a block diagram which shows the flow of the surround signal for left speaker input of the signal processing part in the present Example 2. It is a block diagram which shows the flow of the surround signal for right speaker input of the signal processing part in the present Example 2. It is a block diagram which shows the flow of the surround signal for left speaker input of the signal processing part in the present Example 3. It is a block diagram which shows the flow of the surround signal for right speaker input of the signal processing part in the present Example 3. It is a block diagram which shows the flow of the surround signal for left speaker input of the signal processing part in the present Example 4. It is a block diagram which shows the flow of the surround signal for right speaker input of the signal processing part in the present Example 4. It is a block diagram which shows the part added to the surround system structure of 1st Embodiment in order to implement 2nd and 3rd Embodiment. It is an operation | movement flowchart figure which measures the distance of the viewing-and-listening position and speaker in 2nd and 3rd embodiment. It is a flowchart figure which shows the selection method of the Example in 2nd Embodiment. (A) is a figure which shows the positional relationship of the position of the speaker and listener in Example 5. FIG. (B) is a figure which shows an example of the frequency distribution method of the surround signal in Example 5. FIG. (A) is a figure which shows the process of the left surround signal in Example 5. FIG. (B) is a figure which shows the process of the right surround signal in Example 5. FIG. (A) is a figure which shows the positional relationship of the position of the speaker and listener in Example 6. FIG. (B) is a figure which shows an example of the frequency distribution method of the surround signal in Example 6. FIG. (A) is a figure which shows the process of the left surround signal in Example 6. FIG. (B) is a figure which shows the process of the right surround signal in Example 6. FIG. (A) is a figure which shows the positional relationship of the position of the speaker and listener in Example 7. FIG. (B) is a figure which shows an example of the frequency distribution method of the surround signal in Example 7. FIG. (A) is a figure which shows the process of the left surround signal in Example 7. FIG. (B) is a figure which shows the process of the right surround signal in Example 7. FIG. (A) is a figure which shows the positional relationship of the position of the speaker and listener in Embodiment 3. FIG. (B) is a figure which shows an example of the distribution method of the frequency of the surround signal in Embodiment 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Listening room 15 Seat 100 Sound image localization processing apparatus 132 Front speaker FL Front speaker on the left side FR Front speaker on the right side 200 Signal processing part

Claims (7)

A sound image localization processing device that amplifies two speakers arranged on the front left and right of the listener based on the input sound signals of a plurality of channels, and localizes a sound image laterally with respect to the plurality of listeners,
Controlling the phase of the acoustic signal to be heard from one direction with respect to the listening position of the one listener and the phase of the acoustic signal to be heard from another direction with respect to the listening position of the one listener Signal processing means for localizing the sound image to the side of one listener,
Band dividing means for dividing a signal-processed acoustic signal and a signal-unprocessed acoustic signal into predetermined frequency bands;
Each listener is assigned to each of the divided frequency bands, and the time delay of the acoustic signal that has been signal-processed with respect to the listening position of the other listeners is controlled to the side of the other listeners. Signal correction means for localizing the sound image;
A sound image localization processing apparatus comprising: The listening positions of the plurality of listeners are arranged side by side so as to face the two speakers, and the listening position and the other arranged at a position closer to one of the speakers from a position where the distance from the two speakers is equal. Including at least one listening position disposed at a position closer to the speaker,
The frequency band divided by the band dividing means is divided into at least a low band and a high band,
In the low frequency range, the signal correction unit outputs the sound signal of the channel corresponding to the phase-controlled sound signal output by the speaker when the sound signal is phase-controlled by any speaker. The time delay of the acoustic signal is controlled so that a lateral localization effect is given to the listening position farther away from the speaker, and the phase-controlled acoustic signal is output in any speaker in the high frequency range When the sound is to be transmitted, the sound is transmitted so that a lateral localization effect is given to the listening position closer to the speaker with respect to the sound signal of the channel corresponding to the phase-controlled sound signal output by the speaker. The sound image localization processing apparatus according to claim 1, wherein the time delay of the signal is controlled. The listening positions of the plurality of listeners are arranged side by side so as to face the two speakers, and at least the listening positions arranged at a position closer to one of the speakers from a position where the distance from the two speakers is equal. Consists of two,
The frequency band divided by the band dividing means is divided into at least a low band and a high band,
The signal correction means controls the time delay of the acoustic signal so that a lateral localization effect is given to the listening position closer to the position where the distance to the two speakers is equal in the low frequency range, and the high frequency range 2. The sound image localization according to claim 1, wherein a time delay of the acoustic signal is controlled so that a lateral localization effect is given to the listening position far from a position where the distance to the two speakers is equal. Processing equipment. The listening positions of the plurality of listeners are arranged side by side facing the two speakers, and the listening positions arranged at positions where the distances from the two speakers are substantially equal, and the distances from the two speakers Are configured to include at least one listening position disposed at a position closer to one of the speakers from an equal position and one listening position disposed at a position closer to the other speaker,
The frequency band divided by the band dividing means is divided into a low band, a middle band, and a high band,
In the low frequency range, the signal correction unit outputs the sound signal of the channel corresponding to the phase-controlled sound signal output by the speaker when the sound signal is phase-controlled by any speaker. Control the time delay of the acoustic signal so that a lateral localization effect is given to the listening position that is farther away from the speaker,
When outputting a phase-controlled acoustic signal from any speaker in the high frequency range, the distance to the speaker is greater than the acoustic signal of the channel corresponding to the phase-controlled acoustic signal output by the speaker. Controlling the time delay of the acoustic signal so that a lateral localization effect is given to the listening position closer to the listening position;
The time delay of the acoustic signal is controlled so that a lateral localization effect is given to the listening position at a position where the distances to the two speakers are substantially equal in the middle range. Sound image localization processor. The frequency band divided by the band dividing means is set as a center frequency, a frequency at which no sound pressure dip is calculated based on the installation position of the two speakers and the listening position of the listener,
5. The time correction of the acoustic signal is controlled by the signal correction means so that a lateral localization effect is given to the right listening position or the left listening position in the frequency band. The sound image localization processing apparatus described. A sound image localization processing method that amplifies two speakers arranged on the front left and right sides of a listener based on the input sound signals of a plurality of channels, and localizes a sound image laterally with respect to the plurality of listeners,
Controlling the phase of the acoustic signal to be heard from one direction with respect to the listening position of the one listener and the phase of the acoustic signal to be heard from another direction with respect to the listening position of the one listener A signal processing step for localizing the sound image to the side of one listener,
A band dividing step of dividing a signal-processed acoustic signal and a signal-unprocessed acoustic signal into predetermined frequency bands;
Each listener is assigned to each of the divided frequency bands, and the time delay of the acoustic signal that has been signal-processed with respect to the listening position of the other listeners is controlled to the side of the other listeners. A signal correction process for localizing the sound image;
A sound image localization processing method comprising: A computer included in the sound image localization processing apparatus according to claim 1,
Controlling the phase of the acoustic signal to be heard from one direction with respect to the listening position of the one listener and the phase of the acoustic signal to be heard from another direction with respect to the listening position of the one listener Signal processing means for localizing the sound image to the side of one listener,
Band dividing means for dividing a signal-processed acoustic signal and a signal-unprocessed acoustic signal into predetermined frequency bands;
Each listener is assigned to each of the divided frequency bands, and the time delay of the acoustic signal that has been signal-processed with respect to the listening position of the other listeners is controlled to the side of the other listeners. Signal correction means for localizing the sound image;
A sound image localization processing program characterized by functioning as

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