Voice signal processor

Claim 2

A voice signal processor which comprises: band dividing means for dividing an input signal mixed with noise into frequency bands; voice band detecting means for detecting a portion in the voice band of said divided signal for every channel from said band dividing means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band on the basis of voice band information detected by said voice band detecting means; voice band selecting/emphasizing means for selecting the voice band of the divided signal including noise input thereto from said band dividing means in accordance with the control signal from said band selecting/emphasizing/controlling means, thereby to emphasize said voice band alone; and band synthesizing means for synthesizing said signal emphasized by said voice band selecting/emphasizing means.

Claim 3

A voice signal processor as set forth in claim 1, wherein said voice band detecting means is provided with Cepstrum analyzing means for performing Cepstrum analysis of the divided input signal, peak detecting means for detecting a peak on the basis of the analyzing result, and a voice band detecting circuit to detect the voice band by the use of the peak detected by said peak detecting means.

Claim 4

A voice signal processor as set forth in claim 1, wherein said voice band detecting means is provided with Cepstrum analyzing means for performing Cepstrum analysis of the divided input signal, peak detecting means for detecting a peak on the basis of the analyzing result, formant analyzing means for performing formant analysis on the basis of said Cepstrum analysis result, and a voice band detecting circuit to detect the voice band by the use of the formant information by said formant analyzing means and the peak detected by said peak detecting means.

Claim 5

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; voice band detecting means for detecting a portion in the voice band of the signal divided by said band dividing means for every channel; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting means; band selecting/attenuating/controlling means for outputting a control signal to emphasize the noise band calculated by said noise band calculating means; noise band selecting/attenuating means for selecting the noise band of the divided signal including noise input thereto from said band dividing means in accordance with the control signal from said band selecting/attenuating/controlling means, thereby to attenuate said noise band only; and band synthesizing means for synthesizing the signal attenuated by said noise band selecting/attenuating means.

Claim 6

A voice signal processor as set forth in Claim 5, wherein said voice band detecting means is provided with Cepstrum analyzing means for performing Cepstrum analysis to the divided input signal, peak detecting means for detecting a peak on the basis of the Cepstrum analysis result, formant analyzing means for performing formant analysis on the basis of the Cepstrum analysis result, and a voice band detecting circuit to detect the voice band by the use of the formant information analyzed by said formant analyzing means and the peak detected by said peak detecting means.

Claim 7

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; voice band detecting means for detecting a portion in the voice band of the divided signal for every channel from said band dividing means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band on the basis of the voice band information detected by said voice band detecting means; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting means; band selecting/attenuating/controlling means for outputting a control signal to emphasize the noise band calculated by said noise band calculating means; emphasizing/attenuating means for selecting the voice band of the signal including noise and divided by said band dividing means in accordance with the control signal from said band selecting/emphasizing/controlling means, thereby to emphasize said voice band only, or for selecting the noise band in accordance with the control signal from said band selecting/attenuating/controlling means, thereby to attenuate said noise band only; and band synthesizing means for synthesizing the emphasized/attenuated signal by said emphasizing/attenuating means.

Claim 8

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; voice discriminating means for discriminating a voice portion of the signal divided by said band dividing means; noise predicting means for predicting noise in said voice portion by the use of the voice portion information discriminated by said voice discriminating means; cancelling means for subtracting a noise value predicted by said noise predicting means from the signal divided by said band dividing means; voice band detecting means for detecting a portion in the voice band of said divided signal for every channel; voice band selecting/emphasizing means for emphasizing a voice signal band of the signal from which noise is cancelled by said cancelling means relatively to a noise signal band on the basis of the voice band information detected by said voice band detecting means; and band synthesizing means for synthesizing the signal emphasized by said voice band selecting/emphasizing means.

Claim 9

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; Cepstrum analyzing means for performing Cepstrum analysis of the signal divided by said band dividing means for every channel; peak detecting means for detecting a peak on the basis of the Cepstrum analysis result; a voice discriminating circuit which discriminates a voice portion by the use of the peak detected by said peak detecting means; noise predicting means for predicting noise in said voice portion by the use of the voice portion information obtained by said voice discriminating circuit; cancelling means for subtracting a noise value predicted by said noise predicting means from said divided signal; a voice band detecting circuit which detects the voice band by the use of the peak detected by said peak detecting means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band on the basis of the voice band information detected by said voice band detecting circuit; voice band selecting/emphasizing means for selecting the voice band of the signal from which noise is removed by said cancelling means in accordance with the control signal of said band selecting/emphasizing/controlling means, thereby to emphasize said voice band only; and band synthesizing means for synthesizing the signal emphasized by said voice band selecting/emphasizing means.

Claim 10

A voice signal processor as set forth in claim 9, further comprising formant analyzing means for performing frmant analysis to the Cepstrum by said Cepstrum analyzing means, so that said voice discriminating circuit discriminates the voice portion also by the use of the formant analysis result.

Claim 11

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; Cepstrum analyzing means for performing Cepstrum analysis to the signal divided by said band dividing means for every channel; peak detecting means for detecting a peak on the basis of the Cepstrum analysis result; a voice discriminating circuit which discriminates a voice portion by the use of the peak detected by said peak detecting means; noise predicting means for predicting noise in the voice portion by the use of the voice portion information obtained by said voice discriminating circuit; cancelling means for subtracting a noise value predicted by said noise predicting means from said divided signal; a voice band detecting circuit which detects the voice band by the use of the peak detected by said peak detecting means; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting circuit; band selecting/attenuating/controlling means for outputting a control signal to attenuate the noise band calculated by said noise band calculating means; noise band selecting/attenuating means for selecting the noise band of the input signal from which noise is cancelled by said cancelling means in accordance with the control signal from said band selecting/attenuating/controlling means, thereby to attenuate said voice band only; and band synthesizing means for synthesizing the signal attenuated by said noise band selecting/attenuating means.

Claim 12

A voice signal processor as set forth in claim 11, further comprising formant analyzing means for performing formant analysis to the Cepstrum by said Cepstrum analyzing means, so that said voice discriminating circuit discriminates the voice portion also by the use of the formant analysis result.

Claim 13

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; Cepstrum analyzing means for performing Cepstrum analysis of the signal divided by said band dividing means for every channel; peak detecting means for detecting a peak on the basis of the Cepstrum analysis result; a voice discriminating circuit which discriminates a voice portion by the use of the peak detected by said peak detecting means; noise predicting means for predicting noise in the voice portion by the use of the voice portion information obtained by said voice discriminating circuit; cancelling means for subtracting a noise value predicted by said noise predicting means from said divided signal; a voice band detecting circuit which detects the voice band by the use of the peak detected by said peak detecting means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band on the basis of the voice band information detected by said voice band detecting circuit; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting circuit; band selecting/attenuating/controlling means for outputting a control signal to emphasize the noise band calculated by said noise band calculating means; emphasizing/attenuating means for selecting the voice band of the signal from which noise is cancelled by said cancelling means in accordance with the control signal of said band selecting/emphasizing/controlling means, thereby to emphasize said voice band only, or for selecting the noise band in accordance with the control signal from said band selecting/attenuating/controlling means, thereby to attenuate said noise band only, and band synthesizing means for synthesizing the signal emphasized/attenuated by said emphasizing/attenuating means.

Claim 14

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; Cepstrum analyzing means for performing Cepstrum analysis of the signal divided by said band dividing means for every channel; peak detecting means for detecting a peak on the basis of the Cepstrum analysis result; a voice discriminating circuit which discriminates a voice portion by the use of the peak detected by said peak detecting means; noise predicting means for predicting noise of the voice portion by the use of the voice portion information obtained by said voice discriminating circuit; cancelling means for subtracting a noise value predicted by said noise predicting means from said divided signal; a voice band detecting circuit which detects the voice band by the use of the peak detected by said peak detecting means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band on the basis of the voice band information detected by said voice band detecting circuit; voice band selecting/emphasizing means for selecting the voice band of the input signal from which noise is removed by said cancelling means in accordance with the control signal of said band selecting/emphasizing/controlling means, thereby to emphasize said voice band only; and band synthesizing means for synthesizing the signal emphasized by said voice band selecting/emphasizing means, said voice signal processor further comprising: noise power calculating means for calculating the size of the input noise predicted by said noise predicting means; voice signal power calculating means for calculating the size of the voice signal emphasized by said voice band selecting/emphasizing means; and S/N ratio calculating means for calculating the S/N ratio between the voice signal calculated by said voice signal power calculating means and the noise power calculated by said noise power calculating means, characterized in that said band selecting/emphasizing/controlling means outputs a control signal to said voice band selecting/emphasizing means so that the S/N ratio calculated by said S/N calculating means and input to said controlling means becomes a predetermined target S/N ratio.

Claim 15

A voice signal processor which comprises: band dividing means for dividing an input signal including noise into frequency bands; Cepstrum analyzing means for performing Cepstrum analysis of the signal divided by said band dividing means for every channel; peak detecting means for detecting a peak on the basis of the Cepstrum analysis result; a voice discriminating circuit which discriminates a voice portion by the use of the peak detected by said peak detecting means; noise predicting means for predicting noise of the voice portion by the use of the voice portion information obtained by said voice discriminating circuit; cancelling means for subtracting a noise value predicted by said noise predicting means from said divided signal; a voice band detecting circuit which detects the voice band by the use of the peak detected by said peak detecting means; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting circuit; band selecting/attenuating/controlling means for outputting a control signal to emphasize the noise band calculated by said noise band calculating means; noise band selecting/attenuating means for selecting the noise band of the input signal from which noise is cancelled by said cancelling means in accordance with the control signal of said band selecting/attenuating/controlling means, thereby to attenuate said noise band only; and band synthesizing means for synthesizing the signal attenuated by said noise band selecting/attenuating means, said voice signal processor further comprising: noise power calculating means for calculating the size of the input noise predicted by said noise predicting means; voice signal power calculating means for calculating the size of the voice signal which is relatively emphasized by said noise band selecting/attenuating means; and S/N ratio calculating means for calculating the S/N ratio between the voice signal calculated by said voice signal power calculating means and the noise power calculated by said noise power calculating means, characterized in that said band selecting/attenuating/controlling means outputs a control signal to said noise band selecting/attenuating means so that the calculated S/N ratio input to said controlling means becomes a predetermined target S/N value.

Claim 16

A voice signal processor which comprises: band dividing means for dividing an input voice signal including noise into frequency bands; noise predicting means for predicting a noise component of the signal input thereto from said band dividing means; pitch frequency detecting means for detecting the pitch frequency of said input signal including noise; cancellation factor setting means for setting a cancellation factor corresponding to the pitch frequency output from said pitch frequency detecting means; cancelling means to which are input an output from said noise predicting means, an output from said band dividing means and a signal from said cancellation factor setting means for cancelling the noise component of said output from said band dividing means in consideration of the cancelling rate; voice band detecting means for detecting a portion in the voice band of said input signal by the use of the pitch frequency detected by said pitch frequency detecting means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band detected by said voice band detecting means; voice band selecting/emphasizing means for emphasizing a voice signal band of the signal from which noise is cancelled by said cancelling means relatively to a noise signal band in accordance with the control signal of said band selecting/emphasizing/controlling means; and band synthesizing means for synthesizing the signal emphasized by said voice band selecting/emphasizing means.

Claim 17

A voice signal processor which comprises: band dividing means for dividing an input voice signal including noise into frequency bands; noise predicting means for predicting a noise component of the output input thereto from said band dividing means; pitch frequency detecting means for detecting the pitch frequency of said input signal including noise; cancellation factor setting means for setting a cancellation factor corresponding to the pitch frequency output from said pitch frequency detecting means; cancelling means to which are input an output of said noise predicting means, an output of said band dividing means and a signal of said cancellation factor setting means for cancelling the noise component in the output of said band dividing means in consideration of the cancelling rate; voice band detecting means for detecting the voice band to detect a portion in the voice band of said input signal by the use of the pitch frequency detected by said pitch frequency detecting means; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting means; band selecting/attenuating/controlling means for outputting a control signal to attenuate the noise band calculated by said noise band calculating means; noise band selecting/attenuating means for selecting the noise band of the input signal from which noise is cancelled by said cancelling means in accordance with the control signal of said band selecting/attenuating/controlling means, thereby to attenuate said noise band only; and band synthesizing means for synthesizing the signal attenuated by said noise band selecting/attenuating means.

Claim 18

A voice signal processor which comprises: band dividing means for dividing an input voice signal including noise into frequency bands; noise predicting means for predicting a noise component of the output input thereto from said band dividing means; pitch frequency detecting means for detecting the pitch frequency of said input signal including noise; cancellation factor setting means for setting a cancellation factor corresponding to the pitch frequency output from said pitch frequency detecting means; cancelling means to which are input an output of said noise predicting means, an output of said band dividing means, and a signal of said cancellation factor setting means for cancelling the noise component of the output of said band dividing means in consideration of the cancelling rate; voice band detecting means for detecting a portion in the voice band of said input signal by the use of the pitch frequency detected by said pitch frequency detecting means; band selecting/emphasizing/controlling means for outputting a control signal to emphasize the voice band detected by said voice band detecting means; voice band selecting/emphasizing means for emphasizing a voice signal band of the signal from which noise is cancelled by said cancelling means relatively to a noise signal band in accordance with the control signal of said band selecting/emphasizing/controlling means; and band synthesizing means for synthesizing the signal emphasized by said voice band selecting/emphasizing means, said voice signal processor further comprising: noise power calculating means for calculating the size of the noise predicted by said noise predicting means and input thereto; voice signal power calculating means for calculating the size of the voice signal emphasized by said voice band selecting/emphasizing means; and S/N ratio calculating means for calculating the S/N ratio between the voice signal calculated by said voice signal power calculating means and the noise power calculated by said noise power calculating means, wherein said band selecting/emphasizing/controlling means outputs a control signal to said voice band selecting/controlling means so that the S/N ratio calculated by said S/N ratio calculating means and input to the selecting/emphasizing/controlling means becomes a predetermined target S/N value.

Claim 19

A voice signal processor which comprises: band dividing means for dividing an input voice signal including noise into frequency bands; noise predicting means for predicting a noise component of the output input thereto from said band dividing means; pitch frequency detecting means for detecting the pitch frequency of said input signal including noise; cancellation factor setting means for setting a cancellation factor corresponding to the pitch frequency output from said pitch frequency detecting means; cancelling means to which are input an output of said noise predicting means, an output of said band dividing means and a signal from said cancellation factor setting means for cancelling the noise component of the output of said band dividing means in consideration of the cancelling rate; voice band detecting means for detecting the voice band to detect a portion of the voice band in said input signal by the use of the pitch frequency detected by said pitch frequency detecting means; noise band calculating means for calculating the noise band on the basis of the voice band information detected by said voice band detecting means; band selecting/attenuating/controlling means for outputting a control signal to attenuate the noise band calculated by said noise band calculating means; noise band selecting/attenuating means for selecting the noise band of the input signal from which noise is cancelled by said cancelling means in accordance with the control signal of said band selecting/attenuating/controlling means, thereby to attenuate said noise band only; and band synthesizing means for synthesizing the signal attenuated by said noise band selecting/attenuating means, said voice signal processor further comprising: noise power calculating means for calculating the size of the noise predicted by said noise predicting means and input thereto; voice signal power calculating means for calculating the size of the voice signal relatively emphasized by said noise band selecting/attenuating means; and S/N ratio calculating means for calculating the S/N ratio between the voice signal calculated by said voice signal power calculating means and the noise power calculated by said noise power calculating means, wherein said band selecting/attenuating/controlling means outputs a control signal to said noise band selecting/attenuating means so that the S/N ratio calculated by said S/N ratio calculating means and input to the controlling means becomes a predetermined target S/N value.