JPH03250900A - headphone playback device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to headphone playback on a television or the like.
The present invention relates to a headphone playback device that realizes sound image localization outside the head.

BACKGROUND OF THE INVENTION FIG. 7 shows a block diagram of a conventional headphone playback device. In FIG. 7, reference numeral 1 denotes a sound reproduction device such as a CD that reproduces a stereo sound signal, 2 a stereo amplifier that amplifies the stereo sound signal, and 3 a stereo headphone.

In FIG. 7, a stereo sound signal outputted from a sound reproduction device 1 is amplified via a stereo amplifier 2 and reproduced independently to the left and right ears by stereo headphones 3.

Problems to be Solved by the Invention However, with the above configuration, as is well known, the sound image generated by the acoustic signal is formed in the head or near both ears, giving an unnatural feeling and causing fatigue. There was a problem in that the number increased.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a headphone playback device that realizes out-of-the-head localization of sound images even in headphone playback, and can perform playback similar to normal speaker playback.

Means for Solving the Problems In order to solve the above problems, the hesodophone reproducing device of the present invention includes: an image sound reproducing means for reproducing a stereo sound signal and an image signal; an image reproducing means for monitoring the image signal; first and second input means for inputting signals, and first and second input means for generating spatial crosstalk signals of the signals. Second. Third.
A fourth crosstalk generation means, first and second reflected sound generation means for creating spatial reflected sound and reverberant sound, and a signal input to the first input means and the first reflected sound generation means. a first addition means for adding a signal output from the second crosstalk generation means, a signal output from the fourth crosstalk generation means, and a signal inputted to the second input means; a second addition means for adding the signal output from the second reflected sound generation means, the signal output from the first crosstalk generation means, and the signal output from the third crosstalk generation means; , first and second amplification means for amplifying the added signal, and headphones for independently reproducing the output signals of the first and second amplification means to the left and right ears, respectively.

According to the above-described configuration, the present invention adds a visual effect by reproducing an image synchronized with an audio signal at the same time as the audio signal, and furthermore, the present invention adds a visual effect that occurs during normal stereo speaker reproduction.
By compensating for the spatial crosstalk signal between the left and right channel signals and the influence of the room (reflected sound) during headphone playback, which does not occur during stereophonic playback, it is possible to localize the sound image outside the head during headphone playback. do.

Example Below, regarding a headphone playback device according to an example of the present invention,
This will be explained with reference to the drawings.

FIG. 1 shows a block diagram of a headphone playback device according to an embodiment of the present invention. In FIG. 1, 5 is a video deck that reproduces a stereo audio signal and a video signal synchronized therewith, 6 is a television that monitors video, and 7
．． 8 is an input terminal for inputting a stereo sound signal, 9.17
10.18 is a delay circuit that delays the input signal by a certain amount of time; 11.14 is a filter circuit that gives the input signal a certain amplitude frequency characteristic. 12.15 is a filter circuit that gives a certain amplitude frequency characteristic to the input signal; 13.16 is A delay circuit that delays an input signal by a certain amount of time, 1
9.20 is an adder circuit that inputs multiple signals, multiplies each input signal by a certain value, and adds it; 21.22 is an amplifier circuit that amplifies the input signal; 23 is an amplifier circuit that sends the input acoustic signal to the left and right ears. These are headphones that play independently.

Regarding the headphone playback device configured as above,
Its operation will be explained using drawings.

First, the video deck 5 transmits a stereo sound signal (hereinafter referred to as
The left signal of the stereo signal is called the Lch signal, and the right signal is called the Rch signal), and a video signal synchronized with this audio signal is reproduced. The video signal is input to the television 6 and the video is played back. A stereo sound signal is input to input terminal 7.8. At this time, it is assumed that the Lch signal is inputted to the input terminal 7 and the Rch signal is inputted to the input terminal 8. The input signals are then input to reflected sound generation circuits 11 and 14, respectively, and reflected sound is added thereto. The reflected sound here refers to the reflected sound from walls and the like that occurs when an input stereo signal is reproduced through speakers in a normal listening room.

FIG. 2 is an example of a specific reflected sound generation circuit.

In FIG. 2, 24 is a delay element (τ, ~τn: delay time) that delays a signal by a certain amount of time, and 25 is a multiplier (multiplier) that multiplies the output signal of each delay element 24 by a certain value. 30 is an adder. The value of the multiplier and the delay time of the delay element are determined from the results of actually measuring the structure of reflected sound in a normal sounding room or the like, or from the structure of reflected sound obtained by military aircraft simulation. For example, Figure 3 shows the reflected sound structure determined by computer simulation, where the vertical axis is amplitude and the horizontal axis is time. As shown in FIG. 3, if the delay time of the reflected sound is T1-T4 and the amplitude is 81-B4, τl proverb T1, A1-B.

+2”’T2 Tl, A2””B2 τB""+1 "2, A8"BB Set r2"+4"8"!"Bt.

The output signals of the reflected sound generation circuits 11.14 are each branched into two, one of which is input to an adder circuit 19.20 and the other input to a filter circuit 12.15.

The filter circuit 12 uses crosstalk characteristics measured in an anechoic chamber or the like to create a signal corresponding to the reflected sound signal that is reproduced from the left speaker and reaches the right ear during normal speaker reproduction for the Lch signal. filtering is performed.

Similarly, in the filter circuit 15, filtering is performed on the Rcll signal to create a signal corresponding to a reflected sound signal that is reproduced from the right speaker and reaches the left ear during normal speaker reproduction. Filter circuit 1
The output signals of 2.15 are respectively input to delay circuits 13.16, and are delayed by the time of the delay of the crosstalk signal.
The output signal of the delay circuit 13 is sent to the adder circuit 20 and then to the delay circuit 1.
The output signal of 6 is input to the adder circuit 19.

Fig. 4 shows the relationship of radiated signals during normal speaker reproduction. In Fig. 4, 26 is the left signal speaker, 27
is the right signal speaker, 2B is the human head, DLL is the direct sound that reaches the left ear from the left speaker + DLl is the direct sound that reaches the right ear from the left speaker DIIN is the direct sound that reaches the right ear from the right speaker DIL is The direct sound RLL that reaches the left ear from the right speaker is the reflected sound that reaches the left ear from the left speaker.

RLI is the reflected sound that reaches the right ear from the left speaker.

R111 is the reflected sound RIL reaching the right ear from the right speaker.
is the reflected sound that reaches the left ear from the right speaker.
The figure is a diagram illustrating the amount of delay time of the crosstalk signal set in the delay circuits 13.16 and 10.18. In FIG. 5, 29 indicates the human head, point F indicates the position of the speaker, dotted line indicates the left ear, and point E indicates the right ear. In this diagram,
Assuming that sound is radiated from point F, the difference in distance between point F and H's ear is DG, where G is a point on straight line DF having a distance equivalent to distance 11EF. Therefore, the speed of sound is C
Then, the amount of delay T due to crosstalk is T-1/C (seconds).The delay time of each delay circuit is set based on this idea.

Furthermore, the signals input to the input terminals 7.8 are input to filter circuits 9.17, respectively, and in the filter circuits 9, signals corresponding to the crosstalk of the Lch direct sound are generated, and in the filter circuit 17, A signal corresponding to the crosstalk of the Rch direct sound is generated. In other words, the filter circuit 9 filters the crosstalk characteristics of the direct sound that is reproduced from the left speaker and reaches the right ear in normal speaker reproduction, and the filter circuit 17 filters the crosstalk characteristics of the direct sound that is reproduced from the right speaker and reaches the left ear in normal speaker reproduction. Filtering of the crosstalk characteristics of the arriving direct sound is performed. The output signals of the filter circuits 9 and 17 are input to the delay circuits 10 and 18, respectively, and are delayed by the delay time of the crosstalk signal. is power supply circuit 1
9.

In the power supply circuit 19, plus 1 is applied to the Lch input signal, and minus 1 is applied to the output signal of the reflected sound generation circuit 11.
The output signal of the delay circuit 16 is multiplied by minus 1, and the output signal of the delay circuit 1 day is multiplied by plus 1, and each is weighted and output to the amplifier circuit 21. In the power supply circuit 20, plus 1 is applied to the Rch input signal, and the reflected sound generation circuit 15
The output signal of the delay circuit 13 is multiplied by +1, the output signal of the delay circuit 1o is multiplied by +1, and each is weighted and output to the amplifier circuit 2.
Output to 2. However, the signs of the root values for the input signals in the power adding circuits 19 and 20 may be opposite to each other since they are used to change the phases of the Lch signal and the Rch signal and make them uncorrelated.

Next, the amplifier circuits 21 and 22 amplify the input signals and output the signals to the headphones 23, and the headphones 23 reproduce the acoustic signals to the left and right ears.

In addition, filter circuit 12.15 and filter circuit 9.17
The crosstalk characteristics are set assuming that the directions of sound incidence are different; for example, direct sound is set to enter from a 30-degree direction, and indirect sound is set to enter from a 60-degree direction. Naturally, this characteristic affects the localization of the sound image, so
By making this characteristic variable, various sound image localizations can be realized. Similarly, the delay times of delay circuit 13.16 and delay circuit 10.18 are set to different values.

In addition, the reflected sound generation circuits 11 and 14 can be brought into a more normal speaker playback state by adding a reverberation signal created by combining a circuit that feedbanks the input signal, such as an all-bus filter as shown in Figure 6. The closer it gets, the more effective it will be.

In Figure 6, 31, 35.36 are multipliers, 32.3
3 is a power supply device, and 34 is a delay device. Also, g is the gain, τ
indicates the delay time.

In addition, in this embodiment, the input signals are multiplied by values having different signs in the power adding circuits 19 and 20, but instead of performing a multiplication, the phase characteristics of the input signals are controlled to be different, so that the difference between the signals is The correlation can be made variable, and the localization of the sound image can be controlled more precisely.

Although the audio signal was set to stereo, the monaural signal was set to 2.
Needless to say, the effect is the same even if the input is branched to the above.

Effects of the Invention As described above, the present invention comprises: an image sound reproducing means for reproducing a stereo sound signal and an image signal; an image reproducing means for monitoring the image signal; a second input means and a first input means for generating a spatial crosstalk signal of the signal;
．． Second. Third. a fourth crosstalk generating means, and a first crosstalk generating means for creating spatial reflected sound and reverberant sound. The second reflected sound generation means, the signal input to the first input means, the signal output from the first reflected sound generation means, the signal output from the second crosstalk generation means, a first addition means for adding signals output from the crosstalk generation means of No. 4; a signal input to the second input means; a signal output from the second reflected sound generation means; It is composed of a signal output from the crosstalk generation means and a second addition means for adding the signal output from the third crosstalk generation means, and by simultaneously using the image signal synchronized with the acoustic signal, the visual By adding such effects and further adding signals such as crosstalk, it is possible to reproduce the state of normal speaker playback during headphone playback, and to realize off-the-head localization even during headphone playback.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a headphone playback device according to an embodiment of the present invention, FIG. 2 is a block diagram of a reflected sound generation circuit according to an embodiment of the present invention, and FIG. 3 is a block diagram of a reflected sound generation circuit according to an embodiment of the present invention. FIG. 4 is a diagram showing the relationship between radiated signals during normal speaker reproduction. FIG. 5 is a diagram explaining the delay time set in the delay circuit in an embodiment of the present invention. FIG. 6 is a diagram showing the amplitude characteristics of the circuit. A block diagram of a reflected sound generation circuit according to another embodiment of the present invention, and FIG. 7 is a block diagram of a conventional headphone playback device. 5...Video deck, 6...Television, 78...Input terminal, 9.17...
・Filter circuit, 10.18...Delay circuit, 1
1.14...Reflected sound generation circuit, 12.15...
... Filter circuit, 13゜16 ... Delay circuit, 19.20 ... Addition circuit, 21.22 ...
...Amplification circuit, 23...Headphones.

Claims (4)

[Claims] (1) An image sound reproduction means for reproducing a stereo sound signal and an image signal synchronized with this signal, an image reproduction means for monitoring the reproduced image signal, and two stereo sound signals reproduced by the image reproduction means. first and second input means for inputting two signals, respectively; and a second input means for generating a spatial crosstalk signal of the signal input to the first input means with respect to the signal input to the second input means. 1 crosstalk generation means, and a second crosstalk generation means for generating a spatial crosstalk signal of the signal inputted to the second input means with respect to the signal inputted to the first input means; first and second reflected sound generating means for creating spatial reflected sounds and reverberant sounds from respective signals input to the first and second input means; and generated by the first reflected sound generating means. third crosstalk generation means for generating a spatial crosstalk signal for the signal inputted to the second input means of the signal input to the second input means;
fourth crosstalk generation means for generating a spatial crosstalk signal for the signal input to the first input means of the signal generated by the second reflected sound generation means; and the first input means. Adding the signal input to the , the signal output from the first reflected sound generation means, the signal output from the second crosstalk generation means, and the signal output from the fourth crosstalk generation means. the signal input to the second input means, the signal output from the second reflected sound generation means, and the first
The signal output from the crosstalk generating means and the third
a second addition means for adding the signals output from the crosstalk generation means; first and second amplification means for amplifying respective output signals of the first and second addition means; 1. A headphone reproducing device comprising: headphones for reproducing the output signals of the first and second amplifying means independently to the left and right ears, respectively. (2) A claim characterized in that the first and second reflected sound generation means include delay means for delaying a plurality of input signals by a certain time, and multiplication means for multiplying the delayed signals by a certain value. The headphone playback device according to item (1). (3) The first and second reflected sound generation means include a delay means for delaying the input signal by a certain time, a multiplication means for multiplying the delayed signal by a certain value, and a feedback means for feeding back the input signal. The headphone playback device according to claim 1 or 2, characterized in that: (4) The first, second, third, and fourth crosstalk generation means filter the input signal with certain characteristics, delay the signal by a certain period of time, and independently adjust the phase of the signal. The headphone playback device according to claim 1, characterized in that the headphone playback device controls the headphone playback device.