Music/voice discriminating apparatus

• US 5,375,188 A
• Filed: 06/08/1992
• Issued: 12/20/1994
• Est. Priority Date: 06/06/1991
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kawamura, Akihisa, Matsumoto, Masaharu, Serikawa, Mitsuhiko, Numazu, Hiroko
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): Kim, Richard J.
• Application Number:
  US08/896,044
• Time in Patent Office: 925 Days
• Field of Search: 381/41, 381/11, 381/12, 395/2.24
• US Class Current: 704/215
• CPC Class Codes: G10H 1/0091 Means for obtaining special acoustic effects combined with modulation G10H1/043
• CPC Class Codes: G10H 2210/046 for differentiation between music and non-music signals, based on the identification of musical parameters, e.g. based on tempo detection
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: H04S 7/30 Control circuits for electronic adaptation of the sound field
• CPC Class Codes: H04S 7/305 Electronic adaptation of stereophonic audio signals to reverberation of the listening space H04S7/301 takes precedence

Abstract

A music/voice discriminating apparatus is composed of a signal processing portion for effecting the signal processing upon input acoustic signals, a music/voice deciding portion for discriminating whether the input acoustic signals are music or voice, a first signal processing portion for optimally setting acoustic parameters for the signal processing respectively for music or voice, and a second signal processing portion for controlling the acoustic parameters of the first signal processing portion in accordance with the decision results of the music/voice deciding portion so that it may become a desirable value set in the second parameter setting portion.

Claims

1. An apparatus for discriminating a silence condition, a sound condition, a voice condition and a music condition of two channel L, R acoustic signals, comprising;

an adder for calculating a sum of the two channel L, R acoustic signals to generate a sum output signal,

a subtractor for calculating a difference between the two channel L, R acoustic signals to generate a difference output signal, and

a signal discriminator for discriminating whether the two channel L, R acoustic signals are in the silence condition or in the sound condition, and whether the two channel L, R acoustic signals are in the music condition or in the voice condition when discriminated in the sound condition, the signal discriminator including a sound/silence judging portion for judging the sound condition or the silence condition in accordance with the two channel L, R acoustic signals or the sum output signal generated by said adder, and a music/voice deciding portion for judging whether the two channel L, R acoustic signals are in the music condition or the voice condition in accordance with the sum output signal generated by said adder and the difference output signal generated by said subtractor,

wherein the sound/silence judging portion includes a sound/silence comparing portion for comparing an amplitude of the L acoustic signal and the R acoustic signal or an amplitude of the sum output signal generated by said adder with a predetermined sound/silence judging coefficient so as to discriminate the silence condition when the amplitude is the predetermined sound/silence judging coefficient or less, and so as to discriminate the sound condition when the amplitude is more than the predetermined sound/silence judging coefficient.

2. The apparatus as defined in claim 1, wherein, when the sound/silent judging portion discriminates the silence condition, the judgment of the music/voice judging portion is not effected or the judgment result of the music/voice judging portion is neglected.

3. An apparatus for discriminating a silence condition, a sound condition, a voice condition and a music condition of two channel L, R acoustic signals, comprising;

an adder for calculating a sum of the two channel L, R acoustic signals to generate a sum output signal,

a subtractor for calculating a difference between the two channel L, R acoustic signals to generate a difference output signal, and

a signal discriminator for discriminating whether the two channel L, R acoustic signals are in the silence condition or in the sound condition, and whether the two channel L, R acoustic signals are in the music condition or in the voice condition when discriminated in the sound condition, the signal discriminator including a sound/silence judging portion for judging the sound condition or the silence condition in accordance with the two channel L, R acoustic or the sum output signal generated by said adder, and a music/voice deciding portion for judging whether the two channel L, R acoustic signals are in the music condition or the voice condition in accordance with the sum output signal generated by said adder and the difference output signal generated by said subtractor,

wherein the music/voice deciding portion includes a music comparing portion for comparing a first product of an amplitude of the sum output signal generated by said adder and a predetermined music deciding coefficient with an amplitude of the difference output signal generated by said subtractor, and a voice comparing portion for comparing a second product of the amplitude of the sum output signal generated by said adder and a predetermined voice deciding coefficient with the amplitude of the difference output signal generated by said subtractor, wherein the music comparing portion discriminates the music condition when the amplitude of the difference output signal is larger than the first product, and wherein the voice comparing portion discriminates the voice condition when the amplitude of the difference output signal is smaller than the second product.

4. The apparatus as defined in claim 3, wherein, when the sound/silent judging portion discriminates the silence condition, the judgment of the music/voice judging portion is not effected or the judgment result of the music/voice judging portion is neglected.

5. An apparatus for discriminating a silence condition, a sound condition, a voice condition and a music condition of two channel L, R acoustic signals, comprising;

an adder for calculating a sum of the two channel L, R acoustic signals to generate a sum output signal,

a subtractor for calculating a difference between the two channel L, R acoustic signals to generate a difference output signal, and

a signal discriminator for discriminating whether the two channel L, R acoustic signals are in the silence condition or in the sound condition, and whether the two channel L, R acoustic signals are in the music condition or in the voice condition when discriminated in the sound condition, the signal discriminator including a sound/silence judging portion for judging the sound condition or the silence condition in accordance with the two channel L, R acoustic signals or the sum output signal generated by said adder, and a music/voice deciding portion for judging whether the two channel L, R acoustic signals are in the music condition or the voice condition in accordance with the sum output signal generated by said adder and the difference output signal generated by said subtractor,

wherein, when the sound/silent judging portion discriminates the silence condition, the judgment of the music/voice judging portion is not effected or the judgment result of the music/voice judging portion is neglected.

6. A music/voice processing apparatus comprising;

a signal processing portion for effecting acoustic signal processing such as filtering, addition of initial reflection sounds and reverberation sounds, volume adjustment or the like upon inputted acoustic signals,

a music/voice deciding portion for continuously or periodically deciding whether the inputted acoustic signals are in a music or a voice condition or in a silence condition,

a parameter control portion for variably controlling acoustic parameters for the acoustic signal processing effected by said first signal processing portion in accordance with a decision result of said music/voice deciding portion, and

a parameter setting portion for setting in advance an optimum parameter value for voice, and an optimum parameter value for music,

wherein said parameter control portion is further for gradually correcting an existing state of the acoustic parameters little by little so that the acoustic parameters become closer to the optimum parameter value for music when the music condition is decided, and so that the acoustic parameters become closer to the optimum parameter value for voice when the voice condition is decided in accordance with the continuous or periodic decision results of the music/voice deciding portion, and for maintaining the existing state of acoustic parameters when the silence condition is decided and when discrimination of the music condition and voice condition is hard to effect.