JPH08280100A - Sound field reproducing device - Google Patents

Abstract

PURPOSE: To provide a sound field reproducing device capable of obtaining a spreading feeling and presence without limiting a listening position and speaker arrangement to one place. CONSTITUTION: The audio signals of 2ch are A/D converted and form imaginary sound images on the outer side of first speakers 6-1 and 6-2 in a first signal processing means 13 on one hand. On the other hand, the difference signals of the audio signals are obtained in a signal extraction means 15 and surround signals are prepared. Then, after a signal processing for localizing sound images to the rear right and left or side of a listener in a second signal processing means 14, they are converted to analog signals in a D/A converter 4-2. Thereafter, corresponding to the listening position of the listener inputted to a position input means 11, sound volume to be set to the first speakers 6-1 and 62 and second speakers 6-3 and 6-4 is read from a storage means 17 in a sound volume control means 16 and set no volumes 18-1-184.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound field reproducing apparatus for reproducing realistic sound in AV (audio / visual) equipment.

[0002]

2. Description of the Related Art In recent years, VTRs have been used in the video and audio fields.
In order to enjoy movies at home due to the widespread use of sound, there is a demand for large-screen and realistic sound reproduction, and the development of hardware corresponding thereto is desired.

Particularly in the sound of VTR movie software, a Dolby surround system in which a speaker is arranged laterally or rearward (or a combination thereof) for reproduction as in a movie theater. Is widespread.

Separately from this, a sound field signal for a home TV set or the like so that sound can be heard from the side or the rear without actually placing the speaker on the side or the rear. Playback devices have been developed.

FIG. 13 is a block diagram of such a conventional sound field reproducing apparatus. First, the speaker 6 placed in front
A method of locating sound to the left rear of the viewer using -1, 6-2 will be described with reference to FIG. In FIG. 13, 1 is signal input means for inputting the signal S (t), 2-1 and
2-2 is an A / D converter, 3-1 and 3-2 are signal processing means, 4-1 and 4-2 are D / A converters, 5-1 and 5-2 are amplifiers, 6-1 and 6-2 is a speaker.

In FIG. 13, h1 (t) is the position of the speaker 6-1 and the left ear of the listener 7 (more accurately, when the impulse is input to the signal input means 1, the speaker 6-1 and the eardrum of the left ear). When the measurement is performed, the head related transfer function in the position of the auditory canal entrance (the same applies to the following) is referred to as the impulse response in order to explain in the time domain. , The same result is obtained), h2 (t) is
The impulse response at the position of the speaker 6-1 and the right ear of the listener 7, h3 (t), is the impulse response at the position of the speaker 6-2 and the left ear of the listener 7, and h4 (t) is Speaker 6
-2 and the impulse response at the position of the right ear of the listener 7,
Reference numeral 8 is a signal generating means for generating a signal S (t) of an impulse signal, 9 is a virtual speaker arranged to the rear left of the listener 7.
h5 (t) is the impulse response at the position of the speaker 9 and the listener's 7 left ear, and h6 (t) is the virtual speaker 9 and the listener 7
Is an impulse response at the position of the right ear of.

In such a configuration, the signal generating means 8
When the signal S (t) is emitted from the virtual speaker 9 from the virtual speaker 9, the sound reaching the ear of the listener 7 is L (t) = S (t) * h5 (t) in the left ear L (t). --- (1) In the right ear R (t), R (t) = S (t) * h6 (t) --- (2) (where * represents a convolution operation). (Actually, the transfer function of the speaker itself will be multiplied, but this will be ignored, and the transfer function of the speaker etc. is included in h5 (t) and h6 (t). You may think that).

The impulse response and the signal S (t) are
Think of it as a digital signal with discrete time, and calculate L (t) → L (n) R (t) → R (n) h5 (t) → h5 (n) h6 (t) → h6 (n) S ( t) → S (n) (where, n is actually nT, T is the sampling time, but is generally expressed by omitting T. Also, n is a natural number.) Equation (1) and equation (2) are as shown in (Equation 1) and (Equation 2).

[0009]

[Equation 1]

[0010]

[Equation 2]

Here, N is an impulse response h5 (n), h6
It is the length of (n). Similarly, the signal S (t) changes to the speaker 6
The sound radiated from -1, 6-2 and reaching the listener 7 is L '(t) = S (t) * hL (t) * h1 (t) + S in the left ear L' (t). (t) * hR (t) * h3 (t) --- (5) In the right ear R '(t), R' (t) = S (t) * hL (t) * h2 (t) + S ( t) * hR (t) * h4 (t) --- (6) Similarly, when considered as a discrete digital signal, L '(n) = S (n) * hL (n) * h1 (n) + S (n) * hR (n) * h3 (n) --- (7) R '(n) = S (n) * hL (n) * h2 (n) + S (n) * hR (n) * h4 (n) --- (8).

Assuming that sound can be heard from the same direction if head-related transfer functions are equal (this assumption is generally correct), L (n) = L '(n)-(9) Then, h5 (n) = hL (n) * h1 (n) + hR (n) * h3 (n) --- (10) and R (n) = R '(n) --- (11) At this time, h6 (n) = hL (n) * h2 (n) + hR (n) * h4 (n) --- (12), so that the listener 6-1 and the speaker 6-2 are used. In order to be heard from the left rear, which is the position of the virtual speaker 9, with respect to the expression (10) and the expression (1
It is sufficient to determine hL (n) and hR (n) so as to satisfy 2).

For example, if the equations (10) and (12) are rewritten in the frequency domain expression, the convolution operation is replaced with multiplication, and after that, each impulse response is FFT'ed into a transfer function. Since the transfer functions other than the two transfer functions of the FIR filter are obtained by measurement, the transfer function of the FIR filter can be obtained from these two expressions.

HL (n) and hR (n) thus determined
By radiating the signal S (n) and hL (n) from the speaker 6-1 and the convolution of the signals S (n) and hR (n) from the speaker 6-1. It is possible for the listener 7 to feel as if the sound is coming from behind without actually making the rear speaker 9 sound.

As described above, by inputting the installation position of the virtual speaker 9 to be virtually installed by the sound image position input means 11, the control means is set to the installation position. It is possible to localize the sound image at an arbitrary position by controlling -2.

[0016]

With the above arrangement, however, when listening to the reproduced sound of the sound field reproducing device at a predetermined position, a sense of spaciousness and a sense of realism can be obtained, but the position of the listener changes. Then, the impulse response from the reproduction speaker to the listener changes, so there is a disadvantage that the sound image is not localized at the expected position. In particular, when reproducing using a speaker placed in front of the listener, it is difficult to localize the sound image to the rear of the listener, so that if the listening position shifts, the localization to the rear is greatly affected.

Further, when reproducing using a speaker placed near the listener's ear, it is difficult to localize the sound image in the front.

The present invention solves the above-mentioned conventional problems,
It is an object of the present invention to provide a sound field reproducing device that can provide a feeling of spaciousness and a sense of presence even when the listener's position is slightly displaced.

[0019]

According to a first aspect of the present invention, there is provided a signal input means for inputting a 2ch audio signal, an A / D converter for converting the input signal into a digital signal,
Reflected sound adding means for performing signal processing for adding reflected sound or reverberant sound to the signal converted into the digital signal; and control means for controlling the degree of reflected sound or reverberant sound added by the reflected sound adding means. A D / A converter for converting an output signal from the reflected sound adding means into an analog signal, a first amplifier for amplifying a signal from the signal input means, and the D / A
A second amplifier for amplifying the output of the converter, a first speaker group placed in front of the listener to reproduce the output signal from the first amplifier, and a second speaker placed near the listener's ear.
And a second speaker group for reproducing the output signal from the amplifier.

A second aspect of the invention is a signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and the converted digital signal. First signal processing means for performing desired signal processing, signal extraction means for obtaining a difference or sum of the input 2ch signals, and second signal processing means for converting an output signal from the signal extraction means into a digital signal. A / D converter,
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the second A / D converter;
Control means for controlling the signal processing of the first and second signal processing means, a first D / A converter for converting an output signal from the first signal processing means into an analog signal, and the first A first amplifier for amplifying the output of the D / A converter, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and the second signal processing means. Second D / A converter for converting the output signal of the above into an analog signal, a second amplifier for amplifying the output of the second D / A converter, and the second D / A converter placed near the ear of the listener. And a second speaker group that reproduces a signal from the amplifier.

A third invention is characterized in that the second signal processing means in the second invention performs signal processing for adding reflected sound and reverberant sound.

A fourth invention is characterized in that the first signal processing means in the second invention performs signal processing for localizing a sound image at an arbitrary position.

A fifth invention is a signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and the converted digital signal. First signal processing means for performing desired signal processing, signal extraction means for obtaining a difference or sum of the input 2ch signals, and second signal processing means for converting an output signal from the signal extraction means into a digital signal. A / D converter,
Second signal processing means for performing desired signal processing on the output of the second A / D converter; control means for controlling signal processing of the first and second signal processing means; A first D / A converter for converting the output signal from the first signal processing means into an analog signal; a first amplifier for amplifying the output of the first D / A converter; A first speaker group that is placed and reproduces a signal from the first amplifier; a second D / A converter that converts an output signal from the second signal processing means into an analog signal; and the second D /
A second amplifier that amplifies the output of the A converter, a second speaker group that is placed near the ear of the listener and reproduces a signal from the second amplifier, the first speaker group, and the second speaker group. It is characterized by comprising a volume for varying the volume balance of the speaker group and volume control means for controlling the volume.

A sixth aspect of the invention is a signal input means for inputting a 2ch audio signal, an A / D converter for converting the input signal into a digital signal, and a desired digital signal for the converted signal. A first signal processing means for performing signal processing, a signal extracting means for obtaining a difference or a sum of the input signals of the 2ch, and a second A / D for converting an output signal from the signal extracting means into a digital signal. A converter; second signal processing means for performing desired signal processing on the output of the second A / D converter; control means for controlling the first and second signal processing means; A first D / A converter for converting an output signal from the first signal processing means into an analog signal, a first amplifier for amplifying an output of the first D / A converter, and a front of a listener. Placed on the first amplifier for reproducing the signal from the first amplifier. Group of speakers, a second D / A converter for converting the output signal from the second signal processing means into an analog signal, and a second amplifier for amplifying the output of the second D / A converter. A second speaker group that is placed near the listener's ears and that reproduces the signal from the second amplifier;
A volume control device for adjusting the volume of the first speaker group and the second speaker group, a volume control device for controlling the volume, and a position detection device for automatically detecting the position of the listener are provided. The volume control means controls each of the volumes in accordance with the output of the detection means.

A seventh aspect of the invention is a signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and the input 2ch signal. Signal discriminating means for discriminating whether the signal is voice or non-voice based on the audio signal, correlation degree computing means for obtaining a correlation between the 2ch audio signals, and the first A
First signal processing means for performing desired signal processing on the digital signal converted by the D / D converter, and the input 2c
The signal extraction means for obtaining the difference or the sum of the signals of h, the second A / D converter for converting the output signal from the signal extraction means into a digital signal, and the output of the second A / D converter Second signal processing means for performing desired signal processing, control means for controlling the signal processing of the first and second signal processing means, and an output signal from the first signal processing means are analog signals. A first D / A converter for converting into
A first amplifier for amplifying the output of the D / A converter, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and the second signal processing means. Second D / A converter for converting the output signal of the above into an analog signal, a second amplifier for amplifying the output of the second D / A converter, and the second D / A converter placed near the ear of the listener. A second speaker group that reproduces a signal from the amplifier, a volume that adjusts the volume of the first speaker group and the second speaker group, and a volume control unit that controls the volume. It is characterized in that the volume is controlled by the volume control means using the results obtained by the discrimination means and the correlation degree calculation means.

An eighth aspect of the present invention is a signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and a desired digital signal for the converted signal. Signal processing means for performing the signal processing of the above, a signal extracting means for obtaining a difference or a sum of the input 2ch signals, and a second A / for converting an output signal from the signal extracting means into a digital signal. D converter,
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the second A / D converter;
Control means for controlling the signal processing of the first and second signal processing means, a first D / A converter for converting an output signal from the first signal processing means into an analog signal, and the first A first amplifier for amplifying the output of the D / A converter, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and the second signal processing means. Second D / A converter for converting the output signal of the above into an analog signal, a second amplifier for amplifying the output of the second D / A converter, and the second D / A converter placed near the ear of the listener. Second speaker group for reproducing a signal from the amplifier, a volume for changing the volume balance of the first speaker and the second speaker, and Lch and Rch signals and (LR) signal magnitude Sound source position discriminating means for detecting the sound source position by comparing ; And a volume control means for controlling, is characterized in that to control the volume by the volume control means according to the determined sound source position in the sound source position determination unit.

A ninth aspect of the present invention relates to signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and the converted digital signal. First signal processing means for performing signal processing to localize the sound image of each channel at an arbitrary position, signal extraction means for obtaining the difference or sum of the input 2ch signals, and output from the signal extraction means A second A / D converter for converting the signal into a digital signal;
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the second A / D converter;
Controlling the sound image position changing means for changing the sound image position realized by the second signal processing means and the first and second signal processing means according to the magnitude of the difference signal or the sum signal obtained by the signal extracting means. And a first D / A for converting an output signal from the first signal processing means into an analog signal.
A converter; a first amplifier that amplifies the output of the first D / A converter; a first speaker that is placed in front of a listener to reproduce a signal from the first amplifier; A second D / A converter that converts the output signal from the second signal processing means into an analog signal, a second amplifier that amplifies the output of the second D / A converter, and near the listener's ear And a second speaker that is placed at the position of the second amplifier and reproduces the signal from the second amplifier.

[0028]

According to the first aspect of the invention, the audio signal is input from the input means, the input signal is reproduced from the first speaker installed in front of the listener, and the second signal is installed near the listening position.
By performing signal processing so that the difference component of the input signal is localized laterally or backward at the listening position from the speaker of, the sound field with realistic sensation can be reproduced even if the listening position is slightly displaced. It is possible to do.

In the second and third aspects of the present invention, the reflected sound or the reverberant sound is reproduced from the speaker installed near the listener, so that the reproduction with a realistic feeling can be realized.

According to the fourth aspect of the invention, a sound image is reproduced from a speaker installed near the monitor in a state in which the sound image is localized on both sides of the monitor speaker, so that reproduction with a realistic feeling is possible.

According to the fifth aspect of the invention, by controlling the volume balance of the first speaker and the second speaker by the volume control means, it is possible to perform reproduction with a sense of realism according to the content of the audio signal.

A sixth aspect of the present invention automatically detects the position of the listener and controls the volume balance between the speaker near the monitor and the speaker near the ears, so that the listener has a realistic feeling regardless of the position of the listener. It can be regenerated.

A seventh aspect of the invention is to judge whether the input signal is voice or non-voice and calculate the correlation degree of the input signal. Depending on whether the input signal is voice or non-voice, the speaker near the monitor and the speaker near the ear are selected. By controlling the volume balance, it is possible to perform reproduction with a high degree of clarity or a sense of realism, depending on the content of the input signal.

An eighth invention is that the sound source position discriminating means
Since the volume balance of the first and second speakers is adjusted by the volume according to the magnitude of the difference component between the input 2ch signal and the 2ch signal, the clarity is good according to the input signal.
In addition, it is possible to play back with a realistic feeling.

The ninth invention is 2c obtained by the signal collecting means.
By detecting the difference component of the h signal and controlling the first sound image position by the sound image position changing means according to the magnitude of the difference component, it is possible to achieve a clear and highly realistic reproduction regardless of the type of the input signal. is there.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described below with reference to the drawings.

FIG. 1 is a block diagram of a sound field reproducing apparatus according to the first embodiment of the present invention, and FIG. 2 is a detailed block diagram of the reflected sound adding means 12. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker. The same functions and functions as those of the conventional example are indicated by the same numbers and symbols.

The operation of the sound field reproducing apparatus in the embodiment configured as described above will be described with reference to FIGS. 1, 2 and 3.

In FIG. 1, first, an audio signal of 2ch is input from the signal input means 1, the input audio signal is amplified by the amplifiers 5-1 and 5-2, and the first speaker 6-1. , 6-2.

On the other hand, the signal input from the signal input means 1 is converted into a digital signal by the A / D converter 2,
Based on the control signal from the control means 10, a desired reflected sound or reverberation sound is added in the reflected sound adding means 12. FIG. 2A shows a specific configuration of the case where the reflected sound of the reflected sound adding means 12 is added, and its impulse response is shown in FIG.
It shows in (b). In FIG. 2, 50 is a signal input unit to which the output of the A / D converter 2 is input, 51 is a delay device, 52 is a multiplier, 53 is an adder for adding the signals from the multiplier 52, and 54 is It is a signal output unit for outputting to the D / A converter 4. The structure of the reflected sound adding means in FIG. 2A is the same as that of the FIR filter, and the normal impulse response is set as a tap coefficient as it is, or the impulse response is thinned to simplify the structure. Or Also,
When generating reverberation, it is configured using multiple all-pass filters. Also, a FIR filter and an all-pass filter may be combined.

The signal to which the reflected sound and the reverberant sound are added by the reflected sound adding means 12 is converted into an analog signal by the D / A converter 4, amplified by the amplifiers 5-3 and 5-4, and then the second signal. Are reproduced from the speakers 6-3 and 6-4. An example of speaker arrangement at this time is shown in FIG. Second in FIG.
From the speakers 6-3 and 6-4, signals to which reflected sound, reverberant sound and the like have been added are reproduced, the sense of expanse and the feeling of being wrapped up increases, and reproduction with a sense of realism is possible.

As described above, according to this embodiment, the direct sound is reproduced from the first speakers 6-1 and 6-2 installed in front and reproduced with high clarity, and is received by the reflected sound adding means 12. By adding the reflected sound and the reverberant sound from the second speakers 6-3 and 6-4 placed near the listener, the surround feeling can be further improved.

Embodiments of the present invention described in claims 2 and 4 will be described below with reference to the drawings.

FIG. 4 is a block diagram of a sound field reproducing apparatus according to the second embodiment of the present invention. In FIG. 4, 13 is the first signal processing means, 14 is the second signal processing means, and 15
Is signal extracting means, 2-1 and 2-2 are A / D converters, 4-
Reference numerals 1 and 4-2 are D / A converters, and other configurations are the same as those in the first embodiment. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker.

The operation of the sound field reproducing apparatus in the embodiment constructed as described above will be described with reference to FIG.

In FIG. 4, 2c from the signal input means 1
The audio signal of h is input, and the input audio signal is converted into digital signals by the A / D converters 2-1 and 2-2, and then the first signal processing means 13 and the second signal processing means. 14 is input.

In the first signal processing means 13, the control means 1
Based on the control signal from 0, the first
After performing the signal processing such that the virtual sound sources of Lch and Rch are formed outside the speakers 6-1 and 6-2 of FIG. 1 to widen the stereo sound image according to the principle described in the conventional example, the D / A
The analog signal is converted by the converter 4-1 and the amplifier 5-
The first speakers 6-1 and 6-2 are amplified by 1, 5-2.
Played from.

On the other hand, the signal input from the signal input means 1 is input to the signal extraction means 15 and the difference signal between Lch and Rch is obtained. The difference signal obtained here is generally called a surround signal because reverberation components included in the Lch and the Rch are mainly main components.

The output signal of the signal extracting means 15 is converted into a digital signal by the A / D converter 2-2 and input to the second signal processing means 14, which receives the control signal from the control means 10 based on the control signal. After the signal processing such that the sound image is localized to the left, right, rear or side of the listener is performed according to the principle described in the conventional example, it is converted into an analog signal by the D / A converter 4-2 and the amplifier 5- After being amplified by 3, 5-4, reproduced by the second speakers 6-3, 6-4.

As described above, according to this embodiment, Lch,
The Rch signal is localized in the front because it is reproduced from the front speakers 6-1 and 6-2, while the surround component is the second speakers 6-3 and 6-4 placed near the ears of the listener.
Since it is played back so that there is a sound source on the left, right, rear or side of the listener, direct sound is played from the front and surround sound is played from the side or back even if the listening position and speaker spacing are slightly different. Since the relationship is maintained, it is possible to reproduce the sound field with a realistic feeling.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is the signal input to SL (t) and the signal input to the R channel are used by using the signal extracting means 15. To S
Let R (t). ) Was calculated, and signal processing was performed so that the sound image was localized to the left, right, rear, or side of the listener, but the sum of SL (t) and SR (t) was calculated instead of the difference signal. The signal may be subjected to signal processing such that a sound image is localized to the left, right, rear, or side of the listener.

An embodiment of the invention described in claim 3 will be described below with reference to the drawings. FIG. 5 shows the third aspect of the present invention.
3 is a block diagram of a sound field reproducing apparatus in the embodiment of FIG. In FIG. 5, reference numeral 12 is a reflected sound adding means for adding a reflected sound or a reverberant sound to the input signal. The other constituents are the same as those of the third embodiment (FIG. 4), and the same reference numerals are given to omit the description. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker.

With respect to the sound field reproducing apparatus in the embodiment configured as described above, only the operation different from that of the third embodiment will be described with reference to FIG.

The reflected sound adding means 12 adds a desired reflected sound or reverberant sound to the difference signal between the Lch and Rch extracted by the signal extracting means 15 based on the control signal from the control means 10. The specific configuration for adding the reflected sound of the reflected sound adding means 12 will be described with reference to FIG.
As shown in (1), a normal impulse response is set as a tap coefficient as it is with the same configuration as the FIR filter, or an impulse response is thinned out in order to simplify the configuration. Further, when reverberation is generated, it is configured by using multiple all-pass filters. Also, a FIR filter and an all-pass filter may be combined.

As described above, according to this embodiment, the reflected sound and the reverberant sound are added to the difference signal between the Lch and the Rch by the reflected sound adding means 12, so that the surround feeling can be further improved. Becomes Other operations are third
The same as in the above embodiment, the surround signal to which the reflected sound or the like is added is reproduced to the left, right, rear or side during the 2ch stereo reproduction.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is the signal input to SL (t) and the signal input to the R channel are used by using the signal extracting means 15). To S
Let R (t). ) Is calculated and the reflected sound is added to this, but the sum of SL (t) and SR (t) is calculated instead of the difference signal, and the reflected sound may be added to this signal for processing. .

An embodiment of the invention described in claim 5 will be described below with reference to the drawings. FIG. 6 shows a fourth embodiment of the present invention.
It is a figure which shows the structure of the sound field reproduction apparatus in the Example of.
In FIG. 6, 11 is a position input means for inputting the position of the listener, and 18-1, 18-2, 18-3 and 18-4 are volumes. Numeral 17 designates the volumes of the first speakers 6-1, 6-2 and the second speakers 6-3, 6-4 according to the listening position by the volume control means 18-1, 18-2, 18-.
The storage means stores the data to be set in the volumes 3 and 18-4. The rest of the configuration is the same as that of the second embodiment, so its explanation is omitted. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker.

The operation of the sound field reproducing apparatus in the embodiment configured as described above will be described with reference to FIG.

The listener inputs his / her listening position using the position input means 11. When the position is input, the storage means 1
From 7, the volume control means 16 reads the volume set in the first speakers 6-1, 6-2 and the second speakers 6-3, 6-4 according to the input listening position.
These are volumes 18-1, 18-2, 18-3, 1
Set to 8-4. The sound volume is adjusted by decreasing the sound volume of the second speakers 6-3 and 6-4 as the listening position approaches the second speakers 6-3 and 6-4, and conversely as the distance increases. Control for increasing the volume of 6-3 and 6-4 is performed. Other operations are the same as those in the second embodiment described above.

As described above, according to the present embodiment, by inputting one's own listening position by the position input means, with the two speakers set in front of the listener and on the side near the listener's ears, It is possible to reproduce with a certain balance regardless of the listening position.

In this embodiment, the volume data is stored in the storage means 17 in advance, but the volume to be set in the volumes 18-1 to 18-4 is calculated based on the input listening position. May be. Further, the listener may manually adjust the volume without inputting the listening position.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is the signal input to SL (t) and the signal input to the R channel are used by using the signal extracting means 15). To S
Let R (t). ) Was calculated, and signal processing was performed so that the sound image was localized to the left, right, rear, or side of the listener, but the sum of SL (t) and SR (t) was calculated instead of the difference signal. The signal may be subjected to signal processing such that a sound image is localized to the left, right, rear, or side of the listener.

An embodiment of the invention described in claim 6 will be described below with reference to the drawings. FIG. 7 shows a fifth embodiment of the present invention.
3 is a block diagram of a sound field reproducing apparatus in the embodiment of FIG. Two
1 is a listening position detecting means for detecting the position of the listener,
The other configurations are the same as those described in the above-mentioned embodiments, and the same numbers are given. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker.

The operation of the sound field reproducing apparatus in the embodiment constructed as above will be described with reference to FIG.

The Lch and Rch 2ch signals are input from the signal input means 1, converted into digital signals by the A / D converter 2 and input to the first and second signal processing means 13 and 14. The subsequent operation is basically the same as that of the second embodiment (FIG. 4).

The listening position detecting means 21 detects the position of the listener. A magnetic sensor, a temperature sensor, an ultrasonic sensor, and the like are conceivable as the listening position detecting method, and can be easily realized by a known technique.

When the listening position is detected, the positional information is given to the storage means 17 via the volume control means 16, and the volume control means 16 follows the listening position in the same procedure as in the fourth embodiment. The volume of the first speaker 6 is read out from the storage means 17 to adjust the volumes 18-1 to 18-4.
-1, 6-2 and the volume radiated from the second speakers 6-3, 6-4 are controlled. The control method is the same as that of the above-mentioned embodiment.

As described above, according to this embodiment, the listening position detecting means for detecting the position of the listener is provided to detect the position of the listener, and the position is set in front of the listener and laterally near the listener's ears. By automatically controlling the volume of the speaker, it is possible to reproduce in a constant balance regardless of the listening position.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is the signal input to SL (t) and the signal input to the R channel are used by using the signal extraction means 15). To S
Let R (t). ) Was calculated, and signal processing was performed so that the sound image was localized to the left, right, rear, or side of the listener, but the sum of SL (t) and SR (t) was calculated instead of the difference signal. The signal may be subjected to signal processing such that a sound image is localized to the left, right, rear, or side of the listener.

An embodiment of the invention described in claim 7 will be described below with reference to the drawings. FIG. 8 is a hardware block diagram of the sound field reproducing apparatus in the sixth embodiment of the present invention. In FIG. 8, 20 is a signal discriminating means for adding the Lch and Rch input signals and discriminating whether this signal is a voice signal or a non-voice signal, and 19 is a correlation degree computing means for obtaining a correlation amount between the Lch and Rch input signals. Is. Other configurations having the same functions as those of the fourth embodiment (FIG. 6) are indicated by the same reference numerals. FIG. 3 is a diagram showing the positional relationship between the listener and the speaker.

With regard to the sound field reproducing apparatus in the embodiment configured as described above, only the operation different from that of the fourth embodiment will be described with reference to FIG.

In the signal discriminating means 20, the input R
The ch signal SR (t) and the Lch signal SL (t) are added, and the frequency of occurrence of the silent section (interruption of the signal) of the sum signal is detected,
Whether the input signal is a voice signal or a non-voice signal is determined based on the frequency of occurrence, and such determination can be easily realized by a known technique.

FIG. 9 shows the waveform of the audio signal. In FIG. 9, the horizontal axis represents time and the vertical axis represents amplitude.
It shows the case where you say "Thank you very much" as shown in the square. As shown in this figure, in the case of a voice signal, some silent sections are always generated at certain time intervals (in this example, the silent sections are generated twice per second). The signal determining means 20 of the present embodiment utilizes this property, and considers that it is a “voice signal” when a certain number of silent sections occur within a certain time, and considers it as a “non-voice signal” otherwise. This determines whether the signal is voice or non-voice. Then, this determination degree A is set to A = (A + ΔA) for a non-voice signal and A = (A−ΔA) for a voice signal. According to this equation, A becomes small in the case of a voice signal, and A becomes large in the case of a non-voice signal. in this way,
By not deciding whether it is voice or non-voice by "0" or "1", but by deciding a certain amount of ΔA and updating the degree of judgment as in the above equation for each judgment. If an erroneous determination occurs, it can be dealt with.

Next, the correlation calculating means 19 obtains the correlation between the Lch and Rch input signals by the following equation.

Α = | SL (t) -SR (t) | / | SL (t) + SR (t) |-(14) The determination result of the signal determination circuit 20 and the correlation degree calculation means 19 By controlling the volumes 18-1 to 18-4 by the volume control means 16 according to the value, the first speaker 6-1, 6-2 and the second speaker 6-, respectively.
The volume of the signal reproduced from 3, 6-4 is controlled.

According to the above equation, in the case of a monaural signal or a signal close to it, the numerator becomes zero or small, and α also becomes close to zero. For stereo signals (SL (t) and SR (t)
(The correlation between them is low), the molecule becomes larger and α also becomes larger.

Then, the volume control means 16 performs control as in the following equation. FL '(t) = S1 (t) ・ (1-α ・ A) FR' (t) = S2 (t) ・ (1-α ・ A) SL '(t) = S3 (t) ・ α ・ A SR '(t) = S4 (t) .alpha.A However, FL' (t): Output signal of volume 18-1 FR '(t): Output signal of volume 18-2 SL' (t): Volume 18 -3 output signal SR '(t): output signal of volume 18-4 S1 (t): input signal to volume 18-1 S2 (t): input signal to volume 18-2 S3 (t): volume Input signal to 18-3 S4 (t): Input signal to volume 18-4 However, the signal discriminating means 20, the correlation degree calculating means 19 and the volume control means 16 function only during 2ch stereo reproduction, so-called 3-1. System 4-channel stereo playback (sound field playback system used in high-definition broadcasting:
“3” indicates a stereo 2 channel and a center channel, and “1” indicates a surround channel. In the case of 1), the volume control means 16 functions to adjust each input signal at a constant rate.

In the above equation, the first speaker 6-
Adjusting the ratio of FL '(t), FR' (t) reproduced from 1, 6-2 and the signals SR '(t), SL' (t) to be localized rearward or sideways, a natural The addition calculation is done to give a realistic feeling. That is, according to this equation, when the correlation of the input signals is small (the stereo feeling is large), the signal extracted by the signal extracting means 15 is reproduced greatly, and when the correlation of the input signals is large (the stereo feeling is small), Signal extraction means 15
Although the signal extracted by is reproduced small, when the input signal is a completely independent signal, this is a result contrary to the purpose of reproducing the surround signal to the left and right rear. Therefore, the independence of the input signal is determined based on whether the input signal is voice or non-voice. That is, in the case of an audio signal, it is considered that the left and right independence is high. This makes it possible to reproduce the surround signal small when the left and right independence is high, and to reproduce the surround signal largely when the left and right independence is low. It will be possible.

However, in the above equation, the value α of the equation (14) is used as it is, but in actuality, it is used after being converted into a value corresponding to about 0 to 1. Further, this value may be changed depending on how large or small the effect of expanding the stereoscopic effect is.

Further, S1 (t) and S2 (t) are multiplied by (1-α · A), which is the whole volume SL '(t), S depending on the value of α.
This is because R '(t) does not change, and (1-α
A) is not limited to being applied (that is, it may not be applied when the volume may be changed).

The timing of updating .alpha..multidot.A is set at a certain time interval because the effect may fluctuate.

Further, although α represents a correlation amount, it is not used itself, and similarly to the voice discrimination degree A, when α> X, B = (B + ΔB) When α <X, B = (B- ΔB) (where X is a certain value), and B may be used instead of α. This is also for avoiding a phenomenon in which the effect fluctuates depending on the timing of updating α and avoiding erroneous determination.

In the present embodiment, an example is shown in which the signal judging means 20 judges whether the input signal is voice or non-voice based on the frequency of occurrence of the silent section of the signal. Alternatively, the determination may be made by the inclination of the envelope, or the combination of this method and the determination method in the present embodiment may be used.

Further, although the signal judging means 20 makes the judgment by taking the sum of the input signals, it may take the method of making the judgment by each signal without taking the sum.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is input to SL (t) and the R channel by using the signal extracting means 15). The signal is defined as SR (t).), And signal processing was performed to localize the sound image to the left, right, rear, or side of the listener, but not the difference signal, but SL (t) and SR (t). The sum of (t) may be obtained, and signal processing may be performed on this signal so that the sound image is localized to the left, right, rear, or side of the listener.

An embodiment of the invention described in claim 8 will be described below with reference to the drawings. FIG. 10 is a diagram showing the configuration of the sound field reproducing apparatus in the seventh embodiment of the present invention. In FIG. 10, 22 is a sound source position discriminating means for detecting the position of a sound image, and 17 is the volume of the first speaker 6-1, 6-2 and the second speaker 6-3, 6-4 according to the listening position. , 18-1, 18-2, 18 by the volume control means 16
It is a storage means for storing data to be set in each volume of -3 and 18-4.

The operation of the sound field reproducing apparatus in the embodiment constructed as above will be described with reference to FIG.

The inputted signal is inputted to the sound source position discriminating means 22 through the signal extracting means 15. The sound source position determination means 22 determines the magnitudes of the input signals L and R and the difference component (LR), and determines the position of the sound source. When the input signals L and R components are large, it is determined that there is a sound source ahead, and when the difference component is large, it is determined that there is a sound source behind. When the sound source position is determined, the first speaker 6-1 and 6-2 and the second speaker 6-3 and 6-corresponding to the position are stored in the storage unit 17.
The volume control means 16 reads out the volume set to 4 and sets it to the volumes 18-1, 18-2, 18-3 and 18-4. When the L and R components are dominant, the volume of the first speaker is increased, and when the (LR) component is large, the volume of the second speaker is increased.

To adjust the volume, the second speaker 6-3, 6-4, and 6-4, as the listening position approaches the second speaker 6-3, 6-4,
The volume of 6-4 is decreased, and the volume of the second speakers 6-3 and 6-4 is increased as the distance increases.

The following operation is similar to that of the above embodiment.
As described above, according to the present embodiment, the two speakers set in front of the listener and on the side near the listener's ears can perform signal processing means to reproduce in a constant balance regardless of the listening position. It is possible.

In the present embodiment, the volume data is stored in advance in the storage means 17, but the volume to be set in the volumes 18-1 to 18-4 may be calculated by the listening position.

Further, in this embodiment, SL (t) and SR (t) (where the signal input to the L channel is input to SL (t) and the R channel by using the signal extracting means 15). The signal is defined as SR (t).), And signal processing was performed to localize the sound image to the left, right, rear, or side of the listener, but not the difference signal, but SL (t) and SR (t). The sum of (t) may be obtained, and signal processing may be performed on this signal so that the sound image is localized to the left, right, rear, or side of the listener.

An embodiment of the invention described in claim 9 will be described below with reference to the drawings. FIG. 11 is a diagram showing the configuration of the sound field reproducing apparatus according to the eighth embodiment of the present invention. In FIG. 11, reference numeral 23 is a sound image position changing means for changing the sound image position. The rest of the configuration is the same as that of the second embodiment (FIG. 4), so the explanation is omitted. 12 (a) and 12 (b) are diagrams showing a sound image control method.

The operation of the sound field reproducing apparatus in the embodiment constructed as above will be described with reference to FIG.

A difference component (difference signal) of the input 2ch audio signal is obtained by the signal extracting means 15. The obtained difference component is input to the sound image position varying means 23, and the magnitude of the difference signal is obtained by the sound image position varying means 23. The sound image position realized by the first signal processing means 13 is varied according to the obtained magnitude. Specifically, by the control means 10, F shown in FIG.
It is realized by changing the coefficient of the IR filter.

When the sound image position is adjusted to a monaural signal as in the case of news, the difference component of the audio signal of 2ch becomes small. Therefore, as shown in FIG. The sound image position is localized at the position A between 6-2, and the difference component becomes large in a signal having a large difference component between Lch and Rch such as a stereo music signal.
As shown in FIG. 2 (b), the first speakers 6-1, 6-
The control for localizing the sound image position is performed at the positions B and C on both sides of 2 to reproduce the sound field according to the source signal. In this way, the sound image position is changed according to the magnitude of the difference component of the 2ch audio signal obtained by the signal extracting means 15. Further, the variable time of the sound image position is varied so that an unnatural feeling does not occur. Other operations are the same as those in the above-described embodiment.

As described above, according to the present embodiment, by providing the sound image position varying means, by the two speakers set in front of the listener and on the side near the listener's ears,
It is possible to reproduce a sound field that matches the type and content of the input signal.

In this embodiment, SL (t) and SR (t) (where the signal input to the L channel is input to SL (t) and the R channel by using the signal extracting means 15). The signal is defined as SR (t).), And signal processing was performed to localize the sound image to the left, right, rear, or side of the listener, but not the difference signal, but SL (t) and SR (t). The sum of (t) may be obtained, and signal processing may be performed on this signal so that the sound image is localized to the left, right, rear, or side of the listener.

[0099]

As described above, the sound field reproducing apparatus of the present invention is
Speakers are installed in front of the listener and near the listener's ears. While adjusting the volume balance, the input signal is reproduced from the speaker in front of the listener, and the difference component of the input signal is output from the speaker near the listener's ears. By locating and reproducing the sound image in a certain direction, it is possible to reproduce the sound field with a sense of reality.

[Brief description of drawings]

FIG. 1 is a block diagram of a sound field signal reproducing device according to a first embodiment of the present invention.

2A is a configuration diagram of a reflected sound adding unit according to an embodiment of the present invention, FIG. 2B is an explanatory diagram of FIG.

FIG. 3 is a block diagram of a sound field signal reproducing apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a sound field reproducing device according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a sound field reproducing device according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a sound field reproducing device according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram of a sound field reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram of a sound field reproducing device according to a sixth embodiment of the present invention.

FIG. 9 is an explanatory diagram of voice discrimination according to the embodiment of the present invention.

FIG. 10 is a block diagram of a sound field reproducing apparatus according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram of a sound field reproducing device according to an eighth embodiment of the present invention.

FIG. 12 is a diagram showing a sound image control method according to an eighth embodiment of the present invention.

FIG. 13 is a block diagram of a conventional sound field reproducing device.

[Explanation of symbols]

 1 signal input means 2 A / D converter 2-1, 2-2 A / D converter 3 reflected sound adding means 4 D / A converter 4-1 and 4-2 D / A converter 5-1 and 5 -2, 5-3, 5-4 Amplifier 6-1, 6-2 1st speaker 6-3, 6-4 2nd speaker 7 Listener 9 Virtual speaker 10 Control means 11 Sound image position input means 12 Reflected sound Addition unit 13 First signal processing unit 14 Second signal processing unit 15 Signal extraction unit 16 Volume control unit 17 Storage unit 18-1, 18-2, 18-3, 18-4 Volume 19 Correlation degree calculation unit 20 Signal Determining means 21 Listening position detecting means 22 Sound source position determining means 23 Sound image position varying means 50 Signal input unit 51 Delay device 52 Multiplier 53 Adder 54 Signal output unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Katayama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Riko Ogawa 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A signal input means for inputting a 2ch audio signal, an A / D converter for converting the input signal into a digital signal, and a reflected sound or reverberation of the signal converted into the digital signal. Reflected sound adding means for performing signal processing for adding sound, control means for controlling the degree of reflected sound or reverberant sound added by the reflected sound adding means, and an output signal from the reflected sound adding means as an analog signal A D / A converter for converting into a signal, a first amplifier for amplifying a signal from the signal input means, a second amplifier for amplifying an output of the D / A converter, and a D / A converter placed in front of a listener. A first speaker group that reproduces an output signal from the first amplifier; and a second speaker group that is placed near a listener's ear and reproduces an output signal from the second amplifier. Characteristic sound field playback device. 2. A signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and a desired signal for the converted digital signal. First signal processing means for performing processing, signal extraction means for obtaining a difference or sum of the input 2ch signals, and second A / D conversion for converting an output signal from the signal extraction means into a digital signal And the second A /
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the D converter; control means for controlling the signal processing of the first and second signal processing means; A first D / A converter for converting the output signal from the first signal processing means into an analog signal; a first amplifier for amplifying the output of the first D / A converter; A first speaker group that is placed and reproduces a signal from the first amplifier; a second D / A converter that converts an output signal from the second signal processing means into an analog signal; and the second
A second amplifier for amplifying the output of the D / A converter, and a second speaker group placed near the ear of the listener to reproduce the signal from the second amplifier. Sound field playback device. 3. The sound field reproducing apparatus according to claim 2, wherein the second signal processing means performs signal processing for adding reflected sound and reverberant sound. 4. The first signal processing means performs signal processing for localizing a sound image at an arbitrary position.
Sound field reproduction device described. 5. A signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and a desired signal for the converted digital signal. First signal processing means for performing processing, signal extraction means for obtaining a difference or sum of the input 2ch signals, and second A / D conversion for converting an output signal from the signal extraction means into a digital signal And the second A /
The second signal processing means for performing desired signal processing on the output of the D converter, the control means for controlling the signal processing of the first and second signal processing means, and the first signal processing means. First D / A converter for converting the output signal of the above into an analog signal, and a first D / A converter for amplifying the output of the first D / A converter
Amplifier, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and a second D for converting an output signal from the second signal processing means into an analog signal. / A converter, a second amplifier that amplifies the output of the second D / A converter, and a second speaker group that is placed near the ear of the listener and reproduces the signal from the second amplifier. A sound field reproducing apparatus comprising: a volume for varying the volume balance between the first speaker group and the second speaker group; and a volume control means for controlling the volume. 6. A signal input means for inputting a 2ch audio signal, an A / D converter for converting the input signal into a digital signal, and a desired signal processing for the converted digital signal. A first signal processing means, a signal extracting means for obtaining a difference or a sum of the input 2ch signals, a second A / D converter for converting an output signal from the signal extracting means into a digital signal, Second signal processing means for performing desired signal processing on the output of the second A / D converter, control means for controlling the first and second signal processing means, and the first signal A first D / A converter for converting an output signal from the processing means into an analog signal;
A first amplifier for amplifying the output of the D / A converter, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and the second signal processing means. Second D / A converter for converting the output signal of the above into an analog signal, a second amplifier for amplifying the output of the second D / A converter, and the second D / A converter placed near the ear of the listener. The second speaker group that reproduces the signal from the amplifier, the volume that adjusts the volume of the first speaker group and the second speaker group, the volume control means that controls the volume, and the position of the listener. Equipped with a position detecting means for automatically detecting,
A sound field reproducing apparatus characterized in that each of the volumes is controlled by the volume control means according to the output of the position detection means. 7. A signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and an input 2ch audio signal. In addition, a signal discriminating means for discriminating whether the signal is voice or non-voice, a correlation degree calculating means for obtaining a correlation between the 2ch audio signals, and a digital signal converted by the first A / D converter are desired. 1st signal processing
Signal processing means, signal extracting means for obtaining the difference or sum of the input 2ch signals, a second A / D converter for converting an output signal from the signal extracting means into a digital signal, and the second Second signal processing means for performing desired signal processing on the output of the second A / D converter, and the first and second signal processing means.
Control means for controlling signal processing of the signal processing means, a first D / A converter for converting an output signal from the first signal processing means into an analog signal, and the first D / A converter Amplifier for amplifying the output of the first speaker, a first speaker group placed in front of the listener for reproducing the signal from the first amplifier, and an output signal from the second signal processing means as an analog signal. A second D / A converter for converting to a second amplifier, a second amplifier for amplifying the output of the second D / A converter, and a signal from the second amplifier placed near the ear of the listener. A second speaker group for reproduction, the first speaker group and the second speaker group
A volume for adjusting the volume of the speaker group and volume control means for controlling the volume, and the volume control means controls the volume using the results obtained by the signal determination means and the correlation degree calculation means. A sound field reproducing device characterized by being controlled. 8. A signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and a desired signal processing for the converted digital signal. First signal processing means for performing, signal extraction means for obtaining the difference or sum of the input signals of the 2ch, and second A / D converter for converting the output signal from the signal extraction means into a digital signal , The second A /
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the D converter; control means for controlling the signal processing of the first and second signal processing means; A first D / A converter for converting the output signal from the first signal processing means into an analog signal; a first amplifier for amplifying the output of the first D / A converter; A first speaker group that is placed and reproduces a signal from the first amplifier; a second D / A converter that converts an output signal from the second signal processing means into an analog signal; and the second
Second amplifier for amplifying the output of the D / A converter, a second speaker group placed near the ear of the listener to reproduce the signal from the second amplifier, the first speaker and the first speaker Two
Volume that changes the volume balance of the speaker of L, and L
The sound source position discriminating means includes sound source position discriminating means for comparing the magnitudes of ch and Rch signals and (LR) signals to detect the sound source position, and volume control means for controlling the volume. A sound field reproducing device characterized in that the volume is controlled by the volume control means according to the detected sound source position. 9. A signal input means for inputting a 2ch audio signal, a first A / D converter for converting the input signal into a digital signal, and an arbitrary position with respect to the converted digital signal. First signal processing means for performing signal processing for localizing the sound image of each channel, signal extraction means for obtaining a difference or sum of the input 2ch signals, and an output signal from the signal extraction means is a digital signal. A second A / D converter for converting to
Second signal processing means for performing signal processing for localizing a sound image in an arbitrary direction with respect to the output of the D converter, and the second signal processing means according to the magnitude of the difference signal or the sum signal obtained by the signal extracting means.
Sound signal position changing means for changing the sound image position realized by the signal processing means, control means for controlling the first and second signal processing means, and an output signal from the first signal processing means into an analog signal. A first D / A converter for converting, and a first amplifier for amplifying an output of the first D / A converter,
A first speaker placed in front of a listener for reproducing a signal from the first amplifier; and a second D / A converter for converting an output signal from the second signal processing means into an analog signal. A second amplifier that amplifies the output of the second D / A converter, and a second speaker that is placed near the ear of the listener and reproduces the signal from the second amplifier. Characteristic sound field playback device.