JPH0296499A - Acoustic characteristic correcting device - Google Patents

Abstract

PURPOSE:To attain faithful listening to an original audio signal by detecting respective crosstalk components arriving from an R channel speaker at a left ear and from an L channel speaker at a right ear, and adding components to cancel the said components to the audio signals at the respective channels beforehand. CONSTITUTION:A comparator circuit 15 is provided in a correcting device, a reference audio signal LREF 2 fed back by the device is compared with an original reference audio REF generated by a reference audio signal 16, and the crosstalk components arriving from an R channel speaker 4R at an L channel microphone 18L are detected. In the same way, the crosstalk components arriving from an L channel speaker 4L at an R channel microphone 18R are detected, they are added to a characteristic setting circuit 21 to operate an acoustic characteristic variable changing circuit 12, and the components reverse to the crosstalk components are applied to the audio signal at the R and L channels, and the unnecessary components are prevented from entering to the both ears.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an acoustic characteristic correction device, and in particular, to an acoustic characteristic correction device that allows audio signals produced from a speaker to be heard with the same acoustic characteristics as when listening to a headphone. This is what I did.

[Prior Art] Among the users of audio i devices, there are enthusiast users who seek a sense of realism by superimposing an audio signal delayed from the original audio signal onto the original audio signal and outputting it from a speaker. On the other hand, some people desire to listen to audio signals that are faithful to recorded audio signals recorded on records, compact discs, and the like.

For some users of the latter type, if a recording medium records a stereo audio signal separated into L channel and R channel, when listening to the first word of these audio sounds from the speaker, However, there are many people who wish to hear these clearly differentiated.

When a user listens to a stereo audio signal through headphones, the right ear of the headphone
Only the R channel audio signal is provided from the channel unit, and no I-channel audio signal enters the right ear; conversely, the user's left ear receives only the R channel audio signal from the headphone channel unit. The R channel audio signal is given a blank, and the R channel audio signal does not enter the left ear. Users who like this type of listening through headphones may also want to listen to stereo audio signals from speakers.
As mentioned above, I would like to be able to clearly distinguish and listen to these sounds.

[Problems to be Solved by the Invention] However, even in an anechoic chamber, as shown in Figure 2, the L-chanyruspy force emanates from 1L? 7 sound (L
Channel audio signal No. 1) not only reaches the left ear 2L but also reaches the right ear 2R, and the sound produced from the R channel speaker IR (R channel audio signal)
not only reaches the right ear 2R but also reaches the left ear 2L. Therefore, in the left ear 111'2L, the R channel audio signal RAU2 from the R channel speaker IR is heard as a crosstalk component added to the L channel audio signal LAU1, and in the right ear 2R, the R channel audio signal RAUL is heard. , L channel audio signal LAtJ from L channel speaker 1L
2 is added as a crosstalk component and can be heard.

Therefore, it has not been possible to satisfy the demands of enthusiast users who wish to listen to audio signals that are faithful to the reproduced original audio signals.

The present invention has been made in consideration of the above points, and when a stereo audio signal is emitted from a speaker for the user to listen to, the right ear hears only the R channel audio signal, and the left ear hears only the R channel audio signal. It is an object of the present invention to provide an acoustic characteristic correction device that allows only the signal to be heard and allows the user to listen to a sound (audio signal) that is faithful to the original audio signal.

"Means for Solving the Problems" In order to solve the problems, in the present invention, an audio signal is inserted between the audio signal generation source and the speaker driving amplification means, and the input signal 7':: an acoustic characteristic variable means for changing the acoustic characteristic of the first stereo audio signal and applying it to the speaker driving amplification means;
■An R-channel microphone that is compatible with the R-channel audio signal that captures the audio signals emitted from the T-channel and I-channel speakers;
An L-7-Q channel microphone that captures audio signals emitted from the R channel and L channel speakers, and an R channel and L channel microphone. The second audio signal captured by the second audio signal and the first audio signal (no. -li component, and L -1-
V channel speaker power to R channel microphone 1
Characteristic setting for controlling the characteristics of the acoustic characteristic variable means such that a crosstalk component is detected and a signal for canceling the crosstalk component is superimposed on the first audio signal based on the detection result. IJ:ii.

[Operation] The first stereo audio signal given from the audio signal generation source is delivered to the speaker jW dynamic amplification means via the acoustic characteristic variable means, and is output from the R channel and L channel speakers. The sounded audio signal of each channel is captured not only by the corresponding microphone but also by the non-corresponding microphone. In this way, the second audio signals captured by the R and L channel microphones are provided to the characteristic setting means.

The above-mentioned first audio signal is also provided to this characteristic setting means, and the acoustic characteristic is changed so that the first and second audio signals are compared and match each other based on the comparison result. Control the characteristics of the means.

That is, a cross I-reflection component going from the R-channel speaker to the L-channel microphone J\ and a cross-I-return component going from the L-channel speaker to the R-channel microphone are detected, and the crosstalk component is canceled based on the detection results. Characteristics are set so that the signal for recording is superimposed on the first audio signal.

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

[Example] Hereinafter, 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, a power amplifier 3R for an R channel audio signal, and a power amplifier 31 for an L channel audio signal. - is inserted between the power amplifier device 3 consisting of.

First, the acoustic characteristic correction configuration of the acoustic characteristic correction device 10 will be explained. The acoustic characteristic correction device 10 receives stereo audio signals AD (R channel audio signal), (A
U3 and L channel audio signal LAU3),
It fits in the digital interface circuit 11.

This contained audio signal is applied to an acoustic characteristic variable circuit 12 composed of, for example, a digital signal processor.

The acoustic characteristic variable circuit 12 corrects the acoustic characteristics of each of the rL channel and L channel audio signals as described below, and supplies the corrected R channel audio signal to the digital/analog conversion circuit 13R. The R channel audio signal is given to the digital/analog conversion circuit 13L. The digital/analog conversion circuit 13R converts the incoming R channel audio signal into an analog signal and provides it to the power amplifier 3R, and the digital/analog conversion circuit 13L converts the incoming R channel audio signal into an analog signal. It is applied to the power amplifier 3L described above.

Each power amplifier 3R13L has a corresponding speaker 4R1
The input audio signal is amplified so as to drive the speakers 4R14L, and thereby each speaker 4R14L operates to generate sound.

Next, a configuration for setting the content of characteristic correction performed by the acoustic characteristic variable circuit 12 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 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 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.

The reference audio signal generation source 16 is the comparator circuit 1
Under the control of 5, for example, a reference audio signal including only the R channel reference audio signal source F is generated for a predetermined period of time, and based on the signal from the comparator circuit 15, the channel reference audio signal 1. A reference audio signal containing only the signal LREF is generated for a predetermined period of time. This reference audio signal RF,l”
is provided to the above-mentioned acoustic characteristic variable circuit 12 via the digital interface circuit 11, and is also provided to the comparator circuit 15 as a first comparison input.

Also in this setting mode, the reference audio signal is generated from each speaker 4R, 4L. However, since the reference audio signal REF is determined as described above, either one of the speakers 4R or 4Shiba operates to produce sound. [Acoustic'] The S correction correction device includes a microphone 18R1181 for channels 17 and L channel that captures the sound (audio signal) emitted from the speaker 4R14I-.
− is provided.

These microphones are 18R118! - are placed by the listener in the setting mode at the listening points, more precisely at the positions of the listener's right and left ears. Note that in this case, the speaker 11
)(, 4I- and microphone 18R118L are preferably installed on the same plane.

The audio signals captured by each Microphone 18R118L in the setting mode (hereinafter referred to as RA I in the normal mode) 4, LAD4, and the symbols RRE F 2 and L RE F 2 in the setting mode) are the corresponding Microphone amplifier 19R1191-
Amplified through? C1 is further converted into a digital signal via the corresponding analog/'digital conversion circuit 201.2OL and provided as a second comparison input to the comparator circuit 15! j - can be obtained.

The comparator circuit 15 outputs an i-quasi-audio signal REF via the digital interface circuit 1.1 and a reference audio signal RREF2, which is generated once, captured by the microphone 18R or 18L, and converted into an electrical signal.
Or LREF2 is compared, and difference information is obtained and provided to the characteristic setting circuit 21. The characteristic setting circuit 21 sets the characteristic of the acoustic characteristic variable circuit 12 based on the difference information.

Here, if no correction processing is performed, the audio signal RAD4 reaching each microphone 18R518L
, L A D 4 C. As explained in the previous section of 1x, audio signals of non-corresponding channels are superimposed as cross I-re components (see audio signals RAD 2 and L A D 2 in FIG. 2). It has become something like this.

In the case of reference audio signal REFh interpretation I (channel reference audio signal Rn I-E, F), the audio signal L P, E F'2 that reaches the L channel microphone 18 L is a cross between U. This is the talk component.The comparator circuit 15 calculates the audio signal Rr given from the reference audio signal REF and the L channel microphone 18L at the timing when the reference audio signal REF including only the R channel reference audio signal RREF is being output.
By comparing E1=F2, we can detect the appearance of crosstalk components from the R channel speaker 4R to the 1-channel microphone 18.
Wear. Similarly, Ll--v channel reference audio signal L
By using the reference audio signal r (EF) containing only REF, it is possible to detect the appearance of the cross 1-.

'1 total 11F setting circuit 21. Based on the information on how the crosstalk components appear, the acoustic characteristic variable circuit 12 adjusts the crosstalk between the R channel audio signal RAD3 and the L channel audio signal to the R channel microphone 18R. The correction component that can cancel the component is added to the L7 channel audio signal L.
AD'3 is formed and superimposed, and for the L channel A channel audio signal LAD3, a correction signal that can cancel the cross [... The characteristics of the acoustic 1y property variable circuit 12 are set so that a component is formed from the R channel audio signal RAD3 and superimposed.

Using the acoustic characteristic correction device 10 having the above configuration,
A case where a user enjoys a 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 selects the R channel reference audio signal RRE.
The reference audio signal REF containing only F is output from the reference audio signal generation source 16, and the characteristic setting circuit 2
1 sets the characteristics of the acoustic characteristic variable circuit 12 to the initial state. This reference audio signal REF is output from the speaker 4R via the digital interface circuit 11, the acoustic characteristic variable circuit 12, the digital/analog conversion circuit t3R, and the power amplifier 3R.

Note that at this time, since the reference audio signal REF does not include the L channel audio signal, the speaker 4L does not operate to produce sound.

Although the sound is generated from the R channel speaker 4R, the L channel microphone 18L4 also captures the audio signal, and the reference audio signal LRF', F2 captured by the microphone 181- is transmitted to the microphone amplifier 19L and the analog/digital conversion circuit 2OL. The signal is applied to the comparator circuit 15 via.

The comparator circuit 15 uses this fed-back reference audio signal LREF2 and the primitive rate audio signal REF(RR) generated by the reference audio signal generation source 16.
EF') and compare R channel speaker 4R to L.
Cross 1 reaching Chang Yi Le microphone 18L
--Detect the component.

Subsequently, the comparator circuit 15 receives the L channel reference audio signal LRE from the reference audio signal generation source 16.
A reference audio signal REF containing only F is output from the reference audio signal generation source 16, and similarly, from the L channel speaker 4L to the R channel microphone 18.
Detect the crosstalk component reaching R.

The crosstalk components detected in the second manner are provided 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 R channel audio first word and the L channel audio signal.

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 equipment is taken into the acoustic #-7 characteristic correction device 10 via the digital interface circuit 11, and is processed by the acoustic characteristic variable circuit 12 to avoid any crosstalk that may occur. The inverse component of the talk component is added, and then the digital/analog conversion circuit 13R113L and the power amplifier 3R13
The signal is applied to the speaker 4R14L via L to generate sound.

At this time, the audio signal RAD for the right ear and the left ear
4 and L A D 4 are the audio signals from the R channel and L channel speakers 4R and 4L, but as mentioned above, the inverse component of the crosstalk component is added in advance, so This superimposition cancels out the cross component, so that only the R channel audio signal RAD3 given from the digital audio device reaches the right ear as it is, and the digital audio [1ff1% It sounds as if only the L-channel audio signal LAD3 given from the source arrived as is.

Therefore, according to the above-described embodiment, a signal component capable of canceling out the L channel audio signal reaching one ear and the R channel audio signal reaching the left ear is added in advance to generate sound from the speaker. It is possible to make it sound as if only the input R channel audio signal reaches the right ear, and only the - channel audio signal reaches the left ear. That is, it is possible to listen to a sound (audio signal) that is faithful to the original audio signal AD.

Note that - in the above embodiment, the acoustic characteristic variable circuit 1
Although the characteristic setting for 2 is performed by generating a reference audio signal, it may also be performed using the audio signal itself input from a digital audio device. Further, instead of performing the specific setting operation only when the setting switch 14 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 embodiment described above, most of the circuits for correction processing are constructed of digital processing circuits, but they may be constructed of analog blowfish processing circuits. In this case, it is better to connect the audio signal source with an analog output terminal outside the building.

Furthermore, in the above embodiment, the acoustic characteristic correction device]
0 is shown as being separate from the audio signal generation source and the power amplifier device 3, but it may be built in one of these devices.

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

[Effects of the Invention] As described above, according to the present invention, the crosstalk component reaching the left ear from the R channel speaker and the crosstalk component reaching the right ear from the L channel speaker are installed at the listening point. By detecting the feedback signal from the microphone and adding its cancellation component to the audio signal of each channel in advance and making it sound from the speaker of each channel, only the input R channel audio signal is heard in the right ear. Thus, it is possible to obtain an acoustic characteristic correction device that can faithfully reproduce the original audio signal as if only the L channel audio signal had reached the left ear.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the acoustic characteristic correction device according to the present invention, and FIG. 2 is a route diagram for explaining the drawbacks of the conventional system. 3[(,31,4...power amplifier, 4R24L...
・Speaker, 10...Acoustic 'Samurai Urasa equipment, 12...
・Acoustic characteristic variable circuit, 1・1・・Setting switch, 15・
...Comparator circuit, 16...Reference audio signal generation source, 18R11, SL...My 20]4.n, 2
1...Characteristic setting circuit.

Claims (1)

[Scope of Claims] The device is interposed between an audio signal generation source and a speaker driving amplification means, and drives the speaker by changing the acoustic characteristics of an input stereo first audio signal. an R-channel microphone that captures the audio signals emitted from the R-channel and L-channel speakers; and an R-channel microphone that captures the audio signals emitted from the R-channel and L-channel speakers; Compare the L channel microphone corresponding to the L channel audio signal that captures the signal, the second audio signal captured by the R channel and L channel microphone, and the first audio signal given to the acoustic characteristic variable means. A crosstalk component traveling from the R channel speaker to the L channel microphone and a crosstalk component traveling from the L channel speaker to the R channel microphone are detected, and a signal for canceling the crosstalk component is generated based on the detection results. An acoustic characteristic correction device comprising: characteristic setting means for controlling the characteristics of the acoustic characteristic variable means so as to be superimposed on the first audio signal.