JPH0296500A - Acoustic characteristic correcting device - Google Patents

Abstract

PURPOSE:To obtain a sound faithful to an original audio signal by respectively detecting crosstalk components arriving from a right side speaker at a left ear and from a left side speaker to a right ear, and adding cancelling components to cancel them to the audio signals at respective channels beforehand. CONSTITUTION:A comparator circuit 15, a characteristic setting circuit 21, an acoustic characteristic variable changing circuit 12 are added to a correcting circuit. In such a constitution, a reference audio signal LREF fed back by the comparator circuit 15 is compared with an original reference audio signal REF generated by a reference audio signal generating source 16 by taking into consideration the other fed-back reference audio signal RREF, and the crosstalk components arriving from a speaker 4FR to a left-ear-corresponding microphone 18R are detected. In the same way, the crosstalk components arriving at a right-ear-corresponding microphone 18L are detected, and the signals having the reverse components are applied to the respective audio signals with the use of the circuits 21 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of Industry-F] The present invention relates to an acoustic characteristic correction device, and is particularly suitable for use in correcting the acoustic characteristics of a four-channel stereo audio signal.

[Prior Art] A recording medium on which a two-channel stereo audio signal is recorded is provided so that a listener can enjoy an audio signal with a sense of realism. In order for listeners to enjoy the signal, a recording medium is provided on which a four-channel stereo audio signal is recorded.

This 71 channel stereo audio system 1. Recording medium 1 on which the ¥ number is recorded (audio playback from
The audio signals of each channel reproduced by the device are transmitted to the corresponding speakers and outputted. As shown in FIG. 2, a 1-channel audio signal (hereinafter referred to as Fl-audio signal) FLA from FRON 1 to FLA is installed on the front left side of listener 2, and a speaker (hereinafter referred to as 7). ,r；'Lsujiichiriki>lr
R channel audio signal (hereinafter referred to as r;'R audio signal) FR
A is the speaker installed on the front right side of listener 2 (
The rear channel audio signal (hereinafter referred to as RL audio signal) RLA is generated from the speaker (hereinafter referred to as RL speaker) installed on the rear left side of listener 2. call) IR
The rear 1t channel audio signal (hereinafter referred to as RR audio signal) RRA is generated from L and is generated from the speaker IRR installed on the rear right side of listener 2 (hereinafter referred to as RR speaker). .

Such a four-channel audio signal FLA,
A sense of presence is created by FRA, nLA, and RRA.

[Problems to be Solved by the Invention] However, even in a non-c) room, as shown in FIG.
The FL audio signal and the RL audio signal emitted from the RL speaker IRL reach not only the left ear 2L of the listener 2 but also the right ear 2R, and are transmitted to the PR speaker 11' installed on the right side of the listener 2. R and 1(l)
C) (Audio 13) pronounced from speaker IRIi
No. and R, R audio first word is listener 2's right ear 21
1, but also reaches the left ear 2I-. Therefore, the left ear 2I- receives the audio signal of channel 1, channel 71, A1 and Il, I, 4 to 1, the 111 rule speaker 1 and 1, and the audio signal of channel R, l- from IRR. l-″lI A 2 and 11.1-?A
2 is added as a cross component to cross 1.
(In A1 and RRA L, left 1-rule speaker l l”L
.
It is heard as an additional component.

Therefore, it was impossible to undermine the demands of listeners who wanted to hear an audio signal faithful to Oday No. 13 on the unreproduced J+.

The present invention has been made in consideration of the above points.When a 4-channel stereo audio signal is output from speakers corresponding to each channel and listened to by a listener, the right ear can be heard as a 4-channel stereo audio signal. Only the channel audio signal can be heard, and only the channel audio signal can be heard in the left ear.
There are several attempts to provide an acoustic characteristic correction device that allows the user to listen to audio signals (audio signals).

[Means for Solving the Problems] In order to solve the problems, the present invention provides an audio signal generator which is inserted between an audio signal generation source and a speaker driving amplification means, and which receives input 4 channels.・Acoustic characteristic variable means for changing the acoustic characteristics of the first audio signal of the channel stereo system and applying it to the means for driving the speaker 1);
a first microphone corresponding to the right ear of the listener that captures the audio signals emitted from each speaker of channel Qi\channel and R1, FR channel, FL channel;
A second microphone corresponding to the listener's left ear captures the audio signals emitted from the speakers of the channel, channel, IλR channel, and RL channel, and the first and second microphones capture the audio signals. The second audio signal and the first audio signal given to the acoustic characteristic variable means are ratio-coupled, and the signal is sent from the speakers of the FR channel and the RR channel to the second microphone, and the second audio signal and the first audio signal given to the acoustic characteristic variable means are transmitted from the speakers of the FR channel and the RR channel to the second microphone. A crosstalk component directed from the speakers of the channel and RL channel toward the first microphone is detected, and a signal for canceling the crosstalk component is superimposed on the first audio signal based on the detection result. and characteristic setting means for controlling the characteristics of the acoustic characteristic variable means.

[Operation] The first stereo audio signal obtained from the audio signal generation source is delivered to the speaker driving amplification means via the acoustic characteristic variable means, and is output from the speakers of each channel. The sounded audio signal of each channel is captured as a crosstalk component not only by the corresponding microphone but also by non-corresponding microphones. In this way, the second audio signal captured by the first and second microphones is provided to the characteristic setting means.

The above-mentioned first audio signal is also given to this characteristic setting means, and the acoustic characteristic changing means compares these first and second audio signals and adjusts the sound characteristics so that they match based on the comparison result. control the characteristics of

That is, crosstalk components from the FR channel and RR channel speakers to the second microphone and crosstalk components from the Fl-channel and RL channel speakers to the first microphone are detected, and the detection results are Based on this, the characteristics of the acoustic characteristic variable means are controlled so that a signal for canceling the crosstalk component is superimposed on the first audio signal.

As a result, by placing the microphone at the listening points 1 to 1, the listener can hear the audio f3 that is faithful to the stereo first audio signal.

[Example] Below-1, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1, the acoustic characteristic correction device 10 of this embodiment includes digital audio equipment (not shown) such as a compact disc player and a digital audio tape recorder, and power amplifiers 3FR and FL for I''R audio signals.
The audio signal power amplifier 3 F L, n is inserted between the power 2 amplifier device 3 consisting of the audio signal power amplifier 3111k and the RL audio signal power amplifier 3RL.

First of all, this sound! Acoustics of characteristic correction device 10 1. The configuration for correcting the ν property will be explained. The instrumentation characteristic correction device 10 receives a four-channel stereo audio signal AD (front and rear R channel audio signals FRA3, RRA3, front and rear L channel audio signals FLA3, RL, A3) output from a digital audio device. , digital interface circuit 1]9. This contained audio signal AD is transmitted to an acoustic characteristic variable circuit 12 composed of, for example, a digital signal processor.
given to.

The acoustic 1-1ν variable circuit 12 outputs the audio signals FRA3, FLA3, Ftlmen A3, RL of each channel.
The acoustic characteristics of each A3 are corrected as described later, and the corrected audio signals of each channel are converted to corresponding digital/analog conversion circuits 13FR113FL and 13RR.
Give to 11311L. Each digital/analog conversion circuit 13FF, 13F L, 13RR113RL converts an incoming audio signal into an analog signal and converts the incoming audio signal into an analog signal to the corresponding power amplifier 3FR13F L, 3RR13 described above.
Give to RL.

Each power amplifier 3FR13FL, 3RR13RL has a corresponding speaker 4F, R14F L, 4RR4RL.
The input audio signal is amplified to drive each speaker 4FR14FL, 4r'tR141 (L
The pronunciation works.

Next, a configuration for setting the content of characteristic correction performed by the acoustic characteristic variable circuit 12 will be explained. Note that this setting is configured to be performed while the digital audio device is powered off.

This setting operation is started by operating the setting switch 14. The setting mode signal outputted by the setting switch 14 is applied to a comparator circuit 15 constituted by a microcomputer. Comparator circuit 15
When the setting mode 1- is instructed, a starting signal is given to the reference audio signal generation source 16, and the acoustic characteristic variable circuit 12 is set to an initial state in which no correction operation is performed via a characteristic setting circuit 21, which will be described later. be.

The reference audio signal generation source 16 is the comparator circuit 1
Under the control of 5, for example, a quasi-audio signal REF that matches only the FR channel reference audio signals FRR, IE is generated for a predetermined period of time, and then 1"i-
+7-Yannel Tsume Sumitomo Oteoii Word F L R
Reference audio signal RE I? is generated for a predetermined period of time, and then a reference audio signal 1q containing only the RR channel reference audio signal RRRE is generated.
E +: is generated for a predetermined time, and after i, Iq L,
, channel reference audio signals RL R, EF containing only R, E are generated for a predetermined time. This reference audio signal REF is sent to the above-mentioned acoustic characteristic variable circuit 1 via the digital interface circuit 11.
2 and directly to the comparator circuit 15 as a first comparison input.

, 2 setting mode, the reference audio signal is generated from each speaker 4FR14F"L, 4RR14RL. However, as mentioned above, the reference audio signal R
Since EF is specified, either one speaker 4FR
Only 14FL, 4[e or 4RL are activated to produce sound.

The acoustic characteristic correction device 10 includes each speaker 4FF and 4FL.
, 4RR14RL sound (audio signal)
It is equipped with two microphones 18R118L that capture the information. These microphones 18R5]8I1 are arranged to be placed by the listener at the listening points, more precisely at the right and left ears of the listener, in the setting mode. In this case, the speaker, ↓DoR, 4F L2. 'l RR14Rt, a
Himaita 07 <', y181, l 8 L, are the same]' I hope it is installed on the open surface, -jl-
L.

Audio signals captured by each microphone in the setting mode (hereinafter referred to as fl A I in the 1:'9 mode), L, A D,
In the setting mode L-', the sign F<7'? IΣr;
, r-, reEr; (not represented by 20 Y
1, 201-, the signal is converted into a digital signal and applied to the °ζ comparator circuit 15 as a second ratio diaphragm input.

The comparator circuit 15 generates an audio signal r?
1-1 Obtain the difference information: 1. Compare with LJ L 'I E F 1-1 Obtain the difference information:
11 years old.

'l, Explosion J: Setting 1' + j) hjiij 21 is the difference 'ti脣 with the two old units and the sound! The characteristics of the temporal i'i]' variable circuit 12 are set.

Here, if no correction processing is performed, the audio signal RAD reaching each microphone 18R, 18L,
L, AD are audio signals FI-, A2, FRA2,
(see RL A 2 and L RA 2).

In the case where only the reference audio signal REF or the FR channel reference audio signal F R,RE is included, the audio signals L R,E F that reach the left ear compatible microphone 18L are crosstalk components that pose a problem. The comparator circuit 15 then outputs the reference audio signal REF and the left ear compatible microphone t8 at the timing when the reference audio signal REF including only FR and the channel reference audio signal FRRE is output.
By comparing the audio signal L RE F given from L and L, it is possible to detect how the cross j--r component from the FR speaker 4FR toward the left ear microphone 18L appears. Note that at this time, the crosstalk component is detected more accurately by considering the other fed-back reference audio signal RREF.

Similarly, with the reference audio signal REF containing only the FL channel reference audio signal FLRE, it is possible to detect the appearance of crosstalk components from the FL speaker 4FI- to the right ear compatible microphone 18R, and also to detect the appearance of the crosstalk component from the FL speaker 4FI- to the right ear corresponding microphone 18R. By using the reference audio first word REF that includes only RRRE, it is possible to detect the appearance of the cross component from the RR speaker 4RR to the left ear compatible microphone 18L. Using the reference audio signal REI'' included in the reference audio signal REI, it is possible to detect how a crosstalk component appears from the RL speaker 4 RL to the right ear compatible microphone 18R.

The characteristic setting circuit 21 allows the acoustic characteristic variable circuit 12 to set the FL audio signal to the right ear compatible microphone 18R for the FR audio signal FRA3 based on the information on how the crosstalk components appear detected in this manner. A correction component capable of canceling the cross [-] component is formed from the FL audio signal FLA3 and superimposed on it. The characteristics of the acoustic characteristic variable circuit 12 are set so as to form and superimpose a correction component from the FR audio signal FRA3 that can cancel out the crosstalk component caused by the noise.

Similarly, the characteristic setting circuit 21 allows the acoustic characteristic variable circuit 12 to adjust the R
For the R audio signal RRA3, a correction component capable of canceling the crosstalk component caused by the RL audio signal for the right ear compatible microphone 18R is added to the R audio signal RRA3.
, L audio signal RLA3, and conversely, for the RL audio signal RLA3, a correction component capable of canceling the crosstalk component caused by the RR audio signal for the left ear compatible microphone 18L is added to the RR audio signal RLA3. The characteristics of the acoustic characteristic variable circuit 12 are set so as to form the signal RRA 3 and superimpose it.

Using the acoustic characteristic correction device 10 having the above decay,
A case where a user enjoys a four-channel stereo audio signal AD from a digital audio device will be described. In this case, the user is required to perform a characteristic setting operation on the acoustic characteristic variable circuit 12 before enjoying listening.

The user operates the setting switch 14 after installing the microphones 18R and 18L at the positions of the left and right ears at the listening point. At this time, the comparator circuit 15 first outputs the FR channel reference audio signal FR.
A reference audio signal REF containing only RE is output from the reference audio signal generation source 16, and the characteristics of the acoustic characteristic variable circuit 12 are set to an initial state by the characteristic setting circuit 21. This reference audio signal REF is output from the speaker 4FR via the digital interface circuit 11, the acoustic characteristic variable circuit 12, the digital/analog conversion circuit 13FR, and the power amplifier 3FR. Note that at this time, since the reference audio signal REF does not include audio signals of other channels, the speakers 4FL and 4RR24RL do not operate to produce sound.

Although the sound is coming from the FR speaker 4FR set on the right side, the left ear compatible microphone 18 [, also captures the audio signal, and the reference audio signal LREF captured by this microphone 18L is generated by the microphone amplifier 19L, analog/digital. It is applied to the comparator circuit 15 via the conversion circuit 2OL.

The comparator circuit 15 uses the fed-back reference audio signal LREF and the basic rate audio signal REF (FRR) generated by the reference audio signal generation source 16.
E) is compared while considering the other reference audio signal RREF that is fed back.
The Talostok component reaching the left ear compatible microphone 18I from Fr is detected.

Subsequently, the comparator circuit 15 causes the reference audio signal generation source 16 to output a reference audio signal REF containing only the F L channel A reference audio signal F L RE, and similarly, Cross 1 to 1 components reaching right ear microphone 18F (from L, speaker 4FI-) are detected.

Thereafter, the comparator circuit 15 converts the reference audio signal REF from the reference audio signal source 16 to 17t, which includes only the R channel reference audio signal R, R, RE.
' is output from the reference audio signal generation source 16, and in the same way, the crosstalk j component reaching the left ear compatible microphone 18L from the 1 (1) speaker -I RR is detected.

Finally, the comparator circuit 15 outputs the RL channel reference audio signal RL from the reference audio signal source 10.
A reference audio signal REF containing only RIpe is outputted from the reference audio first word generation source 16, and in the same manner,
RL speaker 4 Ri- to right ear compatible microphone 1
Detect the cross (2) and - (4) components that reach 81t.

The crosstalk detected in this way is given to the characteristic setting circuit 21. The characteristic setting circuit 21 sets the characteristic so that the acoustic characteristic variable circuit 12 adds an inverse component of the crosstalk component to the audio signal of each channel.

After completing such a setting operation, the user operates the digital audio device. At this time, the stereo audio signal AD given from the digital audio device is taken into the f-characteristics correction device 10 via the digital interface circuit 11, and the acoustic characteristic variable circuit 12 corrects the cross-stoke that may occur. The inverse component of the component is added, and then the digital/analog conversion circuit 13FR113F l-113RR113RL
And power amplifier 3FR13F L, 3RR13R, L
- through speakers 4FR14F L,, 4r(R,
, 41-(■- is given and pronounced.

At this time, the audio signal RAD for the right ear and the left ear
and I-A D is FR~RL, speaker 4 r-'R
・～, 4 The audio signals from R, I- are 41 (convolved, or ``crossed'' like two series. Since the inverse component of the ``-- component is added in advance, there is no convolution. The crosstalk component is canceled by
Also, to the left ear, it sounds as if the 1)'L audio signal FLA3 and 'RL-audio signal RLA3 given from the digital audio equipment had arrived as they were.

Therefore, according to the embodiment of the -F series, the crosstalk components FL and R [-audio signals reaching the right ear, and the crosstalk components r;'
Since a signal component capable of canceling the n and n, n audio signals was added in advance to generate sound from the speaker, the input F R audio signal F n
Only A3 and GojFt audio signal RRA3 reach the right ear, and F[, audio signal D? LA3 and Ri-
Only the audio signal F-included LA3 can be heard as if it had reached T'l in the left ear.

That is, it is possible to listen to a sound (audio signal) that is faithful to the original audio signal AD.

In addition, in the above-mentioned embodiment, the acoustic characteristic variable circuit 12
Although the characteristics setting for the digital audio signal is performed by generating a reference audio signal, the digital audio
This may be done using the audio f-word itself input from the device. Further, instead of performing a specific setting operation only when the setting switch 1 is operated, the characteristics of the acoustic characteristic variable circuit 12 may be set all the time, although this increases the burden on the comparator circuit 15. .

Further, in the above-described embodiment, most of the circuits for correction processing are constructed of digital processing circuits, but they may be constructed of analog processing circuits.

In this case, there is good compatibility with an audio signal generation source having an analog output terminal.

Furthermore, in the above-described embodiment, the acoustics 1 and the ν correction device 10 are shown to be separate from the audio signal generation source and the power amplifier device 3, but they are not built into either of these devices. It's okay.

Further, in the above-described embodiment, two microphones were provided for detecting crosstalk components, but one microphone may be used in a time-sharing manner.

Furthermore, in the above-mentioned embodiments, correction is performed to cancel out crosstalk components between front-side audio signals and between rear-side audio signals, but the method of cancellation is not limited to this. It is sufficient that the crosstalk component can be canceled out as a whole.

For example, the cancellation component of the crosstalk component generated by the audio signal from the rear speakers is
The signal may be superimposed on the audio signal from the -1 law speaker.

[Effects of the Invention] As described above, according to the present invention, the crosstalk component reaching the left ear from the speaker installed on the right side and the crosstalk component reaching the right ear from the speaker installed on the left side can be reduced. The feedback signal from the microphone installed at the listening point is detected, and the cancellation component is added to the audio signal of each channel in advance and output from the speaker of each channel. To obtain an acoustic characteristic correction device capable of making an original audio signal be heard faithfully so that an audio signal and an RR audio signal reach the right ear, and an FL audio signal and an RL audio signal reach the left ear. Can be done.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the acoustic characteristic correction 1F device according to the present invention, and FIG. 2 is a route diagram for explaining the drawbacks of the conventional system. 3FR13FL, 3 RR13RL...Power amplifier, 4FR14FL, 4RR14RL...Speaker, 1
0... Acoustic characteristic correction device, 12... Acoustic characteristic variable circuit, 14... Setting switch, 15... Comparator circuit, 16... Reference audio signal generation source, 18R1
18L...Microphone, 21...Characteristics setting circuit.

Claims (1)

[Claims] The device is inserted between an audio signal generation source and a speaker driving amplification means, and is capable of changing the acoustic characteristics of an input four-channel stereo first audio signal to achieve the above-mentioned effect. a first microphone corresponding to the listener's right ear that captures audio signals emitted from each of the speakers of the FR channel, FL channel, RR channel, and RL channel; FR channel, FL channel, RR
a second microphone corresponding to the left ear of the listener that captures audio signals emitted from each speaker of the channel and the RL channel; a second audio signal captured by the first and second microphones; The first audio signal given to the characteristic variable means is compared, and crosstalk components from the speakers of the FR channel and RR channel to the second microphone, and the crosstalk components from the speakers of the FL channel and RL channel to the first audio signal are detected. Characteristic setting means for detecting a crosstalk component directed toward the microphone and controlling the characteristics of the acoustic characteristic variable means so as to superimpose a signal for canceling the crosstalk component on the first audio signal based on the detection result. An acoustic characteristic correction device comprising: