JPH08152893A - Mixing device - Google Patents

Abstract

PURPOSE: To provide a mixing device without generating a noise, realizing placement outside head of a sound image and capable of outputting a high quality reproducing sound by providing a mixing means, a filter means and a headphone part. CONSTITUTION: A sound inputted to a microphone 1 transmits through space, and is made an electric signal generally through an antenna 2, a reception circuit 3 and an FM demodulation circuit 4 to become the digital data through an A/D converter 8 after being mixed with a musical sound reproduced by a player 6 in a mixture circuit 5. In sound + musical sound signal having no spatial impression of the digital data, spatial information is incorporated by a digital signal processing circuit(DSP) 9. Then, an audio signal is radio- transmitted to headphones 15-17 after through a D/A converter 11, an FM modulator 12, a transmission circuit 13 and the antenna 14, and audiences loading the headphones 15-17 listen the audio signal so that the sound image is not placed inside the head but placed in front.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing device, and more particularly to mixing an audio signal picked up by a microphone with an input audio signal from music software recorded on a cassette tape, a compact disc, a video disc or the like, The present invention relates to a mixing device that reproduces this mixed output signal in real time.

[0002]

2. Description of the Related Art In recent years, a so-called karaoke system in which an audio signal picked up by a microphone is mixed with an input audio signal from media software such as a cassette tape, a compact disc or a video disc, and the mixed output signal is reproduced in real time. The devices have become popular.

[0003]

By the way, the above-mentioned karaoke apparatus produces a sound from a speaker unless it is used in a soundproofed dedicated room, which causes noise for other people. For this reason, it has been postponed to introduce the karaoke device into a home or a small space where soundproofing is not applied.

For this reason, it is considered to use a headphone device as a noise countermeasure, but when a normal headphone system is used, the sound image is localized in the head, and the impression is that the sound is in the head. Will be given. For this reason, it is not possible to obtain a feeling of sound spread, which is a characteristic of the karaoke apparatus.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mixing device which does not generate noise, realizes out-of-head localization of a sound image, and can output a high-quality reproduced sound. .

[0006]

A mixing device according to the present invention comprises a mixing means for mixing an input audio signal and an audio signal picked up by a microphone, and a filter means for processing a sound field of an output signal from the mixing means. The above problem is solved by having a headphone section for reproducing the output signal of the filter means. The input audio signal here is, for example, a reproduction signal of software such as so-called karaoke, such as accompaniment music software without a song.

In this case, the output signal of the filter means is wirelessly transmitted to the headphone section. The audio signal picked up by the microphone is wirelessly transmitted.
Further, the filter means performs a sound field process with the forward direction in the direction of sound image localization, on the output signal of the mixing means.

[0008]

Since the headphone unit is used, the reproduced sound can be prevented from reaching the third party as noise. Further, since the filter means performs the sound field processing on the output signal of the mixing means with the direction of the sound image localization as the front position, it is possible to realize the out-of-head localization of the sound image and output the reproduced sound of high quality.

[0009]

Embodiments of the mixing apparatus according to the present invention will be described below with reference to the drawings. This example is
Playback input audio signal of so-called karaoke software such as accompaniment music software that does not contain songs recorded on cassette tape, compact disc, video disc, etc. is mixed with the audio signal picked up by the microphone, and this mixture This is a mixing device used as a so-called karaoke device for reproducing the output signal in real time.

In this mixing apparatus, as shown in FIG. 1, for example, an input audio signal for accompaniment obtained by reproducing a video disc 6D by a video disc player 6 and a microphone 1 are picked up and the microphone 1 is picked up. After wireless transmission from the antenna 2 to the antenna 2, the receiving circuit 3
And a mixing circuit 5 for mixing the audio signal supplied via the FM demodulation circuit 4 and a kind of a filter section for subjecting the output signal of the mixing circuit 5 to the sound field processing with the direction of the sound image localization being the front position. It comprises a digital signal processing circuit (hereinafter referred to as DSP) 9 and headphone units 15, 16 and 17 for receiving and reproducing an output signal transmitted from the DSP 9 via a transmission circuit 13 and an antenna 14.

The voice of the singer is picked up by the microphone 1 and wirelessly transmitted to the antenna 2. The audio signal via the antenna 2 is received by the receiving circuit 3. The output signal of the reception circuit 3 is supplied to the FM demodulation circuit 4. The stereo audio signals R and L demodulated by the FM demodulation circuit 4 are mixed by the mixing circuit 5
Is supplied to. The input audio signal from the video disc player 6 is also supplied to the mixing circuit 5, and mixes the audio signal with the input audio signal. The video disc player 6 outputs the input audio signal to the mixing circuit 5 and outputs the reproduced video signal to the video display unit 7 which is, for example, a display device. The output signal of the mixing circuit 5 is converted into a digital signal by the A / D converter 8 and supplied to the DSP 9. RO in DSP9
Using a head acoustic transfer function, which will be described later and stored in M10, the digital signal is subjected to sound field processing with the direction of sound image localization as the forward position, and echo processing is performed using the reverberation coefficient. The digital output signal of this DSP 9 is D
The signal is converted into an analog signal by the / A converter 11 and supplied to the FM modulator 12 for FM modulation. The output signal of the FM modulator 12 is supplied to the transmission circuit 13, and is wirelessly transmitted to the headphones 15, 16 and 17 via the antenna 14.

The DSP 9 has the ROM 10 as described above.
Using the head acoustic transfer function stored in advance, the digital signal is subjected to sound field processing with the direction of sound image localization as the front position. The sound field processing will be described below with reference to FIGS. 2 and 3.

In general, the direction localization of a human sound source is
In addition to the difference in sound pressure between both ears and the time difference, the degree of reflection, diffraction, and scattering occurring in the auricle is used as a clue. The transfer function from the sound source to the ear is the head acoustic transfer function (Head
Related Transter Function: HRTF). Using this HRTF, the sound pressure at the human ear can be calculated. For example, in FIG. 2, the source signal S, humans viewed from the right HRTF H _R, left HR
When TF is H _L , sound pressure P _R in the right ear and sound pressure P in the left ear
_L becomes P _R = H _R · S (1) P _L = H _L · S (2)

When headphones are used, as shown in FIG. 3, the input signals S _R and S _L respectively given to the listener's headphones 15 and the headphone transfer functions G _R and G _{L of the} headphones 15 are used. The relation with the ear sound pressures P _R ′ and P _L ′ is P _R ′ = G _R · S _R ... (3) P _L ′ = G _L · S _{L Here, P R = P R ',} P L = P L' When the above (1), (2), (3) and (4) from the ^{_{equation, S R = (G R -1}} · H R) -S ... (5) _SL = ( _GL- ¹ * _HL ) * S ... (6) is obtained. That is, if the sound source signal S is multiplied by the inverse characteristic of each HRTF and the headphone transfer function as the headphone output, the headphone 15 also hears the same sound as the sound from the sound source position shown in FIG. Such sound image localization can be obtained. DSP9 is ROM1 beforehand
Using the above HRTF stored in 0, (5), (6)
The following calculation is performed.

Further, the DSP 9 performs echo processing by using the reverberation coefficient recorded in the ROM 10 in advance.

The voice input to the microphone 1 propagates through the space, and the antenna 2, the receiving circuit 3 and the FM demodulating circuit 4 are included.
Is converted into a normal electric signal via the player, and is mixed by the player 6 in the mixing circuit 5.
A / D converter 8 after being mixed with the tone signal reproduced in
To become digital data. This digital data is subjected to out-of-head sound image localization processing and echo processing as described above by the DSP 9. That is, this DSP9
As a result, the spatial information is included in the voice + musical sound signal having no spatial impression. Then, the D / A converter 11, F
After passing through the M modulator 12, the transmission circuit 13 and the antenna 14, the audio signal is wirelessly transmitted to the headphones 15, 16 and 17. A listener wearing the headphones 15, 16 and 17 can hear the audio signal so that the sound image is not localized in the head but localized in the front. actually,
Since a listener wearing these headphones often views the image displayed on the image display unit 7 in front, the sound image is easily localized in front by adding the image. Further, as described above, since the reverberation coefficient is also stored in the ROM 10, the headphone 1
Audio signals with echo are output from 5, 16 and 17. The headphones 15, 16 and 17 are provided with a volume so that the listener can freely change the volume.

The mixing apparatus according to the present invention is not limited to the above-mentioned embodiment, and for example, a remote operation device may be used to remotely operate the soft media player. The remote control device can also be attached to a headphone unit or a microphone.

Further, not only a volume is added to the headphone section, but also a limiter is attached to prevent excessive input.

Further, as shown in FIG.
It is also possible to prepare several kinds of RTFs (HRTFs 1 to 4), switch those having a good sense of localization by using a remote control device or a switch, and supply them to the DSP 9 in a selectable manner.

Signal transmission from the microphone to the receiving circuit 3 and from the transmitting circuit 13 to the headphones 15, 16 and 17 may be performed by an optical transmission method instead of the wireless method.

Further, as shown in FIG. 5, the headphone unit 2
The microphone 21 is attached to 0, and the integrated headphone 2
It may be 2.

Further, the volume may be attached to the main body side.

Further, the A / D converter 8 and DS shown in FIG.
The P9 and D / A converter 11 may be replaced with a filter having an analog circuit to form a mixing device having a circuit configuration as shown in FIG.

The other structure of the mixing device substituting the analog fill circuit 23 is the same as that shown in FIG.

[0025]

The mixing device according to the present invention comprises a mixing means for mixing an input audio signal and an audio signal picked up by a microphone, a filter means for processing an output signal of the mixing means in a sound field, and the filter means. Since it has a headphone unit that reproduces the output signal, it is possible to prevent noise from being generated by a third party. Here, since the filter means performs the sound field processing in which the direction of the sound image localization is the front position on the output signal from the mixing means, the missing device according to the present invention realizes the out-of-head localization of the sound image, and It can output quality playback sound.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a schematic configuration of a mixing device according to the present invention.

FIG. 2 is a diagram for explaining a method of obtaining a sound pressure at a position of a human ear using a head acoustic transfer function.

FIG. 3 illustrates the relationship between the input signals S _R and S _{L applied} to the headphones of the listener, the headphone transfer functions G _R and G _L of the headphones, and the sound pressure P _R ′ and P _L ′ of both ears. FIG.

FIG. 4 is a diagram showing a case where several types of head acoustic transfer functions are prepared in a ROM.

FIG. 5 is an external view of a microphone-integrated headphone.

FIG. 6 is a diagram showing a schematic configuration of a mixing device using an analog filter circuit.

[Explanation of symbols]

 1 Microphone 3 Reception Circuit 4 FM Demodulation Circuit 5 Mixing Circuit 6 Player 7 Video Display 9 DSP 10 ROM 12 FM Modulation Circuit 13 Transmission Circuits 15, 16 and 17 Headphones

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04S 1/00 F

Claims (4)

[Claims] 1. A mixing means for mixing an input audio signal and an audio signal picked up by a microphone, a filter means for processing a sound field of an output signal of the mixing means, and a headphone section for reproducing the output signal of the filter means. And a mixing device. 2. The output signal of the filter means is wirelessly transmitted to the headphone section.
The described mixing device. 3. The mixing device according to claim 1, wherein the audio signal picked up by the microphone is wirelessly transmitted. 4. The mixing device according to claim 1, wherein the filter means performs a sound field process with the front position in the direction of sound image localization on the output signal of the mixing means.