JPH02142300A - Sound field correction device - Google Patents

Abstract

PURPOSE:To reproduce a sound field similar to an optimum listening point of a concert hall by storing the sound collection microphone transmission characteristic of plural concert halls and the optimum listening point transmission characteristic and correcting an audio signal on the concert stage into the audio signal of plural channels. CONSTITUTION:The audio signal via a digital interface circuit 10 is given to a 1st acoustic characteristic variable circuit 11, in which the acoustic characteristic is varied and given to a 2nd acoustic characteristic variable circuit 12. When desired concert hall information is inputted, the 2nd acoustic characteristic variable means 12 extracts the optimum listening point transmission characteristic as to a desired concert hall from a storage means and uses the extracted transmission characteristic so as to correct the acoustic characteristic of the audio signal of plural channels given from the 1st acoustic characteristic variable means 11. Thus, the user can enjoy the audio listening similar to that at the optimum listening point of the desired concert hall.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sound field correction device, and in particular, is intended to generate a sound field similar to what a user would hear in a desired performance hall.

[Prior Art] In order to enhance the sense of reality, there is a recording medium that records two channels of audio signals.
There is an audio device that outputs a channel audio signal. In other words, the R channel audio signal (
There is an audio system that produces an L-channel audio signal (sound) from a speaker installed on the front left side.

However, the R channel audio signal also reaches the left ear and is heard as a crosstalk component, and conversely, the L channel audio signal also reaches the right ear and is heard as a crosstalk component, and the audio signals output from each speaker are The audio signal output from the audio device does not reach only the corresponding ear and is not heard as is.

Therefore, the same inventor installed microphones at the positions of the left and right ears, compared the audio signals captured by these microphones with the original audio signal, and listened to the original audio signal at the ear positions to determine the acoustic characteristics of the original audio signal. It has been proposed that the correction should be made so that it becomes the same as if it were present, that is, to remove the crosstalk component.

[Problems to be Solved by the Invention] However, even if the two-channel audio signal reproduced in this manner can be heard faithfully, there are users who are not satisfied. That is, even with this arrangement, the audio signal is not the same as that heard in a performance hall or recording studio (hereinafter collectively referred to as a performance hall).

Some users also have preferences regarding performance halls, and some users want to be able to listen to music in the same way as if they were listening in their favorite performance hall, even when listening in their own playing room.

The present invention has been made in consideration of the above points, and provides a sound field that can reproduce a sound field in the user's listening room that is similar to the sound field that the user is listening to at the optimal listening point in the performance hall desired by the user. The present invention attempts to provide a correction device.

[Means for Solving the Problem] In order to solve the problem, the present invention improves the transmission characteristics of audio signals from the performance stage of the performance hall to the sound collection microphone of each channel, or vice versa, for a plurality of performance halls. sound collection microphone transfer characteristic storage means for storing characteristics; recording performance hall information output means for outputting recording performance hall information instructed by an input operation; and recording performance hall information given from the recording performance hall information output means. , extract the transfer characteristics or inverse characteristics to the sound collection microphone for the recording performance hall, and use the extracted transfer characteristics or inverse characteristics to calculate the acoustic characteristics of multiple channels of audio signals given from the audio signal source. a first acoustic characteristic variable means for correcting the signal back to the audio signal on the performance stage of the performance hall where the signal was recorded; Optimum listening point transfer characteristic storage means for storing transfer characteristics of audio signals; desired performance hall information output means for outputting desired performance hall information specified by input operation; and audio output from the first acoustic characteristic variable means. According to the desired performance hall information outputted by the desired performance hall information output means, the optimal listening point transfer characteristic for the desired performance hall is retrieved from the optimal listening point transfer characteristic storage means, and the optimal listening is performed from the performance stage of the desired performance hall. and second acoustic characteristic variable means for correcting audio signals of multiple channels toward the point.

[Function 1 The sound collection microphone transfer characteristic storage means stores in advance, for a plurality of performance halls, the transmission characteristics of audio signals directed from the performance stage of the performance hall to the sound collection microphones of each channel, or vice versa. .

The user inputs the recorded performance hall information regarding the recording medium to be reproduced into the recorded performance hall information output means, and the recorded performance hall information output means outputs the recorded performance hall information to the first acoustic characteristic variable means. Output. The first acoustic characteristic variable means collects, from the sound collecting microphone transfer characteristic storage means, a transfer characteristic to the sound collection microphone or an inverse characteristic for the recording performance hall in accordance with the given recording performance hall information, and The acoustic characteristics of a plurality of channels of audio signals given from an audio signal source are corrected using the derived transfer characteristics or inverse characteristics so as to return them to the audio signals on the performance stage of the performance hall where the audio signals were recorded.

In addition, the optimal listening point transfer characteristic storage means includes:
For a plurality of performance halls, transmission characteristics of audio signals of each channel from the performance stage of the performance hall to the optimum listening point are stored in advance.

The user inputs performance hall information that the user desires to listen to into the desired performance hall information output means, and the desired performance hall information output means outputs the desired performance hall information to the second acoustic characteristic variable means. The second acoustic characteristic variable means extracts the optimum listening point transfer characteristic for the desired performance hall from the optimum listening point transfer characteristic storage means according to the given desired performance hall information, and uses the extracted transfer characteristic to adjust the first acoustic characteristic. Corrects the acoustic characteristics of the plurality of channels of audio signals given from the acoustic characteristic variable means.

As a result, the user can enjoy the same audio signal (sound) as if listening at the optimal listening point of the desired performance hall, regardless of the recording performance hall.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a two-channel audio signal AD (RADI, LADi) output from a digital audio device such as a compact disc player or a digital audio tape recorder (not shown) is sent to the sound field correction device via a digital interface circuit 10. It fits in. The audio signal via the digital interface circuit 10 is applied to a first acoustic characteristic variable circuit 11 to have its acoustic characteristics changed, and then is applied to a second acoustic characteristic variable circuit 12.

The first acoustic characteristic variable circuit 11 is, for example, a digital filter circuit using a digital signal processor (DSP), and is an R-channel audio signal input according to a setting value set by the first characteristic setting circuit 13. The acoustic characteristics of RAD1 and L channel audio signal LAD1 are varied.

The first characteristic setting circuit 13 outputs setting values (coefficients for each coefficient unit of the digital filter circuit) for varying the acoustic characteristics when the hall compatible characteristic setting mode is instructed from the operation panel 14, and when this mode is instructed. To output a set value that allows the input 2-channel audio signal to pass through as it is without changing it when the audio signal is not input. Also, the first
The characteristic setting circuit 13 calculates a setting value according to the recording performance hall information and the desired performance hall information given from the operation panel 14 and outputs it to the first acoustic characteristic variable circuit 11. The audio signals RAD2 and LAD2, the acoustic characteristics of which have been changed according to the set values, are converted into audio signals similar to those heard at the specified desired performance hall.

Here, the first characteristic setting circuit 13 is, for example, a microcomputer, and its data ROM stores predetermined performance halls rAAA'', rBBBJ, . . . as shown in FIG.
・A transfer characteristic table TAB for each is stored. The stored transmission characteristics are as shown in FIG.
Transfer characteristics of audio signals towards CHIRA and CH
ILA, CHIRB, CHILB... and the optimal listening point I of the performance hall from the performance stage 15
・Transfer characteristics of audio signals toward the left and right ear positions at 17 CH2RA, CH2LA, CH2RB and C
H2LB...

The first characteristic setting circuit 13 stores, from the operation panel 14, recording performance hall information regarding the recording medium on which the input audio signals RADI and LADl are recorded and desired performance hall information desired by the user. The transfer characteristics for both performance halls are shown in the transfer characteristic table T above.
Calculate the set value from AB.

More specifically, we extract the transfer characteristics of the audio signals from the performance stage to each sound collection microphone for the recording performance hall, obtain the inverse characteristics of these transfer characteristics, and use the inverse characteristics to convert the audio signals on the performance stage. Get the setting value to restore.

Next, the transmission characteristics of the audio signal from the performance stage to the left and right ear positions at the optimal listening point for the desired performance hall are determined, and set values for realizing these transmission characteristics are obtained. Finally, the setting values for returning to the audio signal on the performance stage in the recording performance hall,
In order to create an audio signal from the performance stage in the desired performance hall to the listening point, the set value is synthesized with the set value to finally form the set value, and the set value for the first acoustic characteristic variable circuit 11 is calculated.

Note that some storage jackets and storage cassettes for recording media on which audio signals are recorded have information about the recording and performance hall written on them, and the recording and performance hall information can be input using the operation panel 14. .

In this manner, by passing through the first acoustic characteristic variable circuit 11, the two-channel audio signals RAD1 and LADl reproduced from the recording medium are directed from the performance stage of the desired performance hall to the optimal listening point. and LAD2, and the converted audio signals RAD2 and LA
D2 is applied to the second acoustic characteristic variable circuit 12.

The second acoustic characteristic variable circuit 12 corrects the acoustic characteristics of each of the R channel and L channel audio signals RAD2 and LAD2 as described later, and converts the corrected R channel audio signal into a digital/analog conversion circuit &8.
18R, and also provides the corrected L channel audio signal to a digital/analog conversion circuit 18L. The digital/analog conversion circuit 18R converts the incoming R channel audio signal into an analog signal and supplies it to the power amplifier 19R.
8L converts the incoming L channel audio signal into an analog signal and supplies it to the above-mentioned power amplifier 19L.

Each power amplifier 19R119L has a corresponding speaker 2
The input audio signal is amplified to drive the OR 12OL, and each speaker 20R12OL thereby operates to generate sound.

Next, a configuration for setting the contents of acoustic characteristic correction performed by the second acoustic characteristic variable circuit ]-2 will be described. Note that this setting is configured to be executed while the digital audio device is powered off.

This setting operation is started by selecting the feedback correction setting mode using the operation panel 14. The setting mode signal outputted from the operation panel 14 is applied to a comparator circuit 21 having a microcomputer configuration. The comparator circuit 21 provides an activation signal to the reference audio signal generation source 22 when the setting mode is instructed, and does not perform a correction operation on the second acoustic characteristic variable circuit 12 via a second characteristic setting circuit 23 to be described later. This is to be set to the initial state.

The reference audio signal generation source 22 is a comparator circuit 2
For example, under the control of the comparator circuit 21, a reference audio signal containing only the R channel reference audio signal RREF is generated for a predetermined period of time, and then the L channel reference audio signal LR is generated based on the signal from the comparator circuit 21.
A reference audio signal containing only EF and REF is generated for a predetermined time. This reference audio signal REF is given to the second acoustic characteristic variable circuit 12 mentioned above, and
It is given to the comparator circuit 21 as a first comparison input.

Also in this setting mode, the reference audio signal is emitted from each speaker 20R12OL.

However, since the reference audio signal REF is defined as described above, either one of the speakers 20R or 2OL
Only the pronunciation works. The sound field correction device is a speaker 2
It is equipped with R channel and L channel microphones 24R124L that capture sounds (audio signals) produced by the OR22OL. These microphones 24R
124L is arranged to be placed by the listener at the listening point, more precisely at the position of the listener's right ear and left ear, in the setting mode. Note that in this case, it is desirable that the speaker 2OR12OL and the microphone 24R1241- are installed on the same plane.

The audio signals captured by each microphone 24R124L in the setting mode (hereinafter represented by symbols RAD3 and LAD3 in the normal mode, and symbols RREFI and LREFI in the setting mode) are amplified via the corresponding microphone amplifier 25R525L, and further, Corresponding analog/digital conversion circuit 26R126
It is converted into a digital signal via L and is applied to the comparator circuit 21 as a second comparison input.

The comparator circuit 21 connects the directly applied reference audio signal REF to the microphone 24R.
Alternatively, the reference audio signal RREFI or LREFI captured by 24L and converted into an electric signal is compared, and difference information is obtained and provided to the second characteristic setting circuit 23. Second
The characteristic setting circuit 23 sets the characteristic of the second acoustic characteristic variable circuit 12 based on the difference information.

Here, if no correction processing is performed, the audio signal RAD3 reaching each microphone 24R124L
, LAD3 are the audio signals of non-corresponding channels superimposed as crosstalk components, and the audio signals RAD2 input to the second acoustic characteristic variable circuit 12 due to the transmission characteristics of the speakers 20R, 2OL, etc. , is different from LAD2.

When the reference audio signal REF includes only the R channel reference audio signal RREF, the audio signal L reaching the L channel microphone 24L
REFI is a problematic crosstalk component. The comparator circuit 21 then outputs a reference audio signal REF that includes only the R channel reference audio signal RREF.
By comparing the reference audio signal REF and the audio signal RREF1 given from the L channel microphone 24L at the timing when the
The appearance of the cross component toward the R channel speaker 2OR mustard channel microphone 24L is detected. Similarly, L channel reference audio signal LR
By the reference audio signal REF containing only EF, L
The manner in which crosstalk components appear from the channel speaker 2OL to the R channel microphone 24R is detected.

Also, from the reference audio signal RREF and the fed-back reference audio signal RREFI, the speaker 2O
On the other hand, the influence of the reference audio signal L is detected.
REF and fed back reference audio signal LR
The influence of the speaker 2OL is detected from the EFI.

The second characteristic setting circuit 23 allows the acoustic characteristic variable circuit 12 to set the crosstalk component due to the L channel audio signal to the R channel microphone 24R to the R channel audio signal based on the information on how the crosstalk component appears. A correction component that can be canceled out is formed from the L channel audio signal and superimposed, and the L
For the channel audio signal, the second acoustic characteristic variable is used to form and superimpose a correction component from the R channel audio signal that can cancel the crosstalk component caused by the R channel audio signal to the L channel microphone 24L. The characteristics of the circuit 12 are set.

In addition, the second characteristic setting circuit 23 determines that the reference audio signal RREF and the fed-back reference audio signal RREFI match, taking into account the influence of the detected transfer characteristics of the speaker 2OR or 2OL, and The passage characteristics of the second acoustic characteristic variable circuit 12 are set so that LREF and the fed-back reference audio signal LREFI match.

A case in which a user enjoys a stereo audio signal AD from a digital audio device using the sound field correction device having the above configuration will be described. in this case,
Before enjoying listening, the user is required to perform a characteristic setting operation on the first and/or second acoustic characteristic variable circuits 11 and 12.

After the user places the microphones 24R and 24L at the left and right ear positions at the listening point, the user instructs the operation panel 14 to select a setting mode. At this time,
The comparator circuit 21 first outputs a reference audio signal R that includes only the R channel reference audio signal RREF.
The EF is output from the reference audio signal generation source 22, and the characteristics of the acoustic characteristic variable circuit 12 are set to the initial state by the second characteristic setting circuit 23. The output reference audio signal REF described above is output from the speaker 2OR via the acoustic characteristic variable circuit 12, the digital/analog conversion circuit 18R, and the power amplifier 19R. Note that at this time, since the reference audio signal REF does not include the R channel audio signal, the speaker 2OL
The pronunciation doesn't work.

Although the sound is generated from the R channel speaker 2OR, the L channel microphone 24L also captures the audio signal, and the reference audio signal LREF1 captured by the microphone 24L is sent to a comparator via a microphone amplifier 25L and an analog/digital conversion circuit 26L. The signal is applied to the circuit 21.

The comparator circuit 21 uses the fed-back reference audio signal LREFI and the primitive rate audio signal REF (R
REF) to detect the crosstalk component reaching the L channel microphone 24L from the R channel speaker 2OR, and also compare the fed back reference audio signal RREFI with the reference audio signals R, EF.
(RREF) to detect difference information other than the Talostok component.

Subsequently, the comparator circuit 21 receives the L channel reference audio signal LRE from the reference audio signal generation source 22.
A reference audio signal REF containing only F is output from the reference audio signal generation source 22, and similarly, from the L channel speaker 2OL to the R channel microphone 2.
A crosstalk component reaching 4R and difference information other than this crosstalk component are detected.

The thus detected crosstalk components and difference information caused by the transfer characteristics of the speakers 2OR or 2OL are provided to the second characteristic setting circuit 23. The characteristic setting circuit 23 sets the characteristic so that the second acoustic characteristic variable circuit 12 adds an inverse component of the crosstalk component to the R channel audio signal and the R channel audio signal, and Microphone 2 corresponding to the audio signal of each channel input to 12
The characteristics are set so that the audio signals arriving at 4R or 24L match.

After the setting operation for the second variable acoustic characteristic circuit 12 is completed, the user performs a hole-compatible setting operation for the first variable acoustic characteristic circuit 11, if necessary. That is, after instructing the setting mode of the performance hall, the recording performance hall and the desired performance hall are specified.

At this time, the first characteristic setting circuit 13 extracts the transfer characteristics for the sound collection microphone in the designated recording performance hall and the transfer characteristics for the optimal listening point in the desired performance hall, and calculates the set value from these transfer characteristics. is applied to the first variable acoustic characteristic circuit 11 to set the pass characteristic of this variable acoustic characteristic circuit 11.

After completing such setting operations, the user operates the digital audio device. At this time, the stereo audio signal AD given from the digital audio equipment is given to the first acoustic characteristic variable circuit 11 via the digital interface circuit 11 so that the desired performance hall can be played regardless of the recording performance hall. The audio signals RAD2 and LAD2 are converted from the stage to the optimal listening point in the hall, and then the second acoustic characteristic variable circuit 12 adds an inverse component of the crosstalk component that would occur, and the speaker Correction is made taking into account the transmission characteristics of the speaker, and then the speaker 2OR12
It is given to the office lady and pronounced.

At this time, the audio signal RAD for the right ear and the left ear
3 and LAD3 are the audio signals from the R channel and L channel speakers 2OR and 2OL, but since the inverse component of the crosstalk component is added in advance as described above, the audio signals from the speaker 2
Since it is designed to cancel changes in acoustic characteristics caused by OR or 20L, etc., crosstalk components are canceled, and the influence of speakers 2OR or 2OL, etc. is removed.
To the right ear, only the R channel audio signal RAD2 from the performance stage of the desired performance hall to the right ear position, which is the optimal listening point, has arrived as is, and to the left ear, the optimal listening signal from the performance stage of the desired performance hall has arrived. It sounds as if only the L channel audio signal LAD2 heading towards the point's left ear position has arrived as is.

Therefore, according to the above-described embodiment, the user can enjoy the same audio signal in the listening room as if listening at the optimal listening point of the desired performance hall, regardless of the recording performance hall. In addition, according to the above-described embodiment, feedback control is performed so that it sounds as if the R channel audio signal RAD2 reaches only the right ear as it is, and the L channel audio signal LAD2 reaches only the left ear as it is. This makes it even more like listening in a performance hall.

In the above-mentioned embodiment, a 2-channel audio signal has been described, but the present invention can be similarly applied to a sound field correction such as a 4-channel audio signal.

Furthermore, in the above embodiment, setting values are stored for each performance hall, but common setting values may be stored for performance halls that have similar setting values. It's okay.

Furthermore, in the above-described embodiment, the first acoustic characteristic variable circuit 11 converts the audio signal captured by the sound collection microphone in the recording and performance hall into an audio signal on the performance stage, and Although the above embodiment has been shown to perform processing for converting an audio signal of 1 to an audio signal at an optimal listening point of a desired performance hall, a separate acoustic characteristic variable circuit for performing these processing may be provided separately.

Furthermore, in the above embodiment, the transmission characteristics to the sound collection microphone are stored in advance; however,
This reverse characteristic may be stored in advance and used. In this case, the amount of calculation can be reduced compared to the above embodiment.

Further, in the above embodiment, the characteristics of the microphones 24R and 24L provided for feedback control were selected regardless of the characteristics of the sound collection microphone, but the input audio signal in this feedback control is Since it is slightly influenced by the characteristics of the sound microphone, if the characteristics of the feedback control microphone are made similar to those of the sound collection microphone, it is possible to reproduce an audio signal with greater fidelity. In this case, since the characteristics of the sound collection microphone differ depending on the performance hall, amplifiers 25R and 25L amplify the audio signal captured by the feedback microphone.
A characteristic compensation circuit may be provided at the next stage to vary the amount of compensation depending on the desired performance hall.

[Effects of the Invention] As described above, according to the present invention, the user can listen to audio signals similar to those heard at the optimal listening point of the desired performance hall, regardless of the performance hall in which the multi-channel audio signals were recorded. You can enjoy it in your home's Nori-sunning room.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the sound field correction device according to the present invention, FIG. 2 is a chart showing the transfer characteristics for each performance hall stored in the first characteristic setting circuit, and FIG. It is a route map provided for explanation of the method of determining the transfer characteristic. DESCRIPTION OF SYMBOLS 11... First acoustic characteristic variable circuit, 13... First characteristic setting circuit, 14... Operation panel, 15... Performance stage, 16R516L... Sound collection microphone in performance hall, 17. ...The optimal listening point in a performance hall.

Claims (1)

[Scope of Claims] Sound collection microphone transfer characteristic storage means for storing, for a plurality of performance halls, the transfer characteristics of audio signals from the performance stage of the performance hall to the sound collection microphones of each channel, or vice versa; and an input operation. A recording performance hall information output means for outputting the recording performance hall information instructed by the recording performance hall information, and a transmission characteristic or the transmission characteristic to the sound collection microphone for the recording performance hall according to the recording performance hall information given from the recording performance hall information output means. The inverse characteristic is retrieved from the sound collection microphone transfer characteristic storage means, and the acoustic characteristics of the multi-channel audio signal given from the audio signal source are determined using the retrieved transfer characteristic or the inverse characteristic. a first acoustic characteristic variable means for correcting the audio signal back to the on-stage audio signal; and storing transmission characteristics of the audio signal of each channel from the performance stage of the performance hall to the optimal listening point for the plurality of performance halls. an optimal listening point transfer characteristic storage means; a desired performance hall information output means for outputting desired performance hall information specified by the input operation; According to the desired performance hall information outputted by the performance hall information output means, the optimum listening point transfer characteristic for the desired performance hall is retrieved from the above-mentioned optimum listening point transfer characteristic storage means, and the process proceeds from the performance stage of the desired performance hall to the optimum listening point. A sound field correction device comprising: second acoustic characteristic variable means for correcting audio signals of multiple channels.