Formant detecting device and speech processing apparatus
First Claim
1. A formant detecting device comprising:
- frequency analyzing means for calculating the power spectrum of an input speech signal;
contrast enhancing means for enhancing the contrast between a local maximum portion and a local minimum portion in said power spectrum of said input speech signal; and
single threshold value judging means for comparing the power in said power spectrum enhanced by said contrast enhancing means with a threshold value in each frequency band and for judging a frequency band corresponding to said power to be a formant if said power in said enhanced power spectrum exceeds said threshold value.
2 Assignments
0 Petitions
Accused Products
Abstract
A speech processing apparatus for obtaining a processed speech which is natural and comfortable for a listener, by refining a gain value assigned for each frequency band in enhancing formants in a power spectrum. The power spectrum, calculated in a frequency analyzing unit, is subject to contrast enhancement in a contrast enhancing unit, and judged as to whether it is a format or not in each frequency band. In a gain value assigning unit, a gain value of 1 is assigned to a formant, and a gain value smaller than 1 is to a frequency other than formant. A threshold value for each frequency band is determined by a threshold value determining unit in accordance with power spectrum of input speech signal, to eliminate the effect of variation in speech level.
-
Citations
14 Claims
-
1. A formant detecting device comprising:
-
frequency analyzing means for calculating the power spectrum of an input speech signal; contrast enhancing means for enhancing the contrast between a local maximum portion and a local minimum portion in said power spectrum of said input speech signal; and single threshold value judging means for comparing the power in said power spectrum enhanced by said contrast enhancing means with a threshold value in each frequency band and for judging a frequency band corresponding to said power to be a formant if said power in said enhanced power spectrum exceeds said threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A formant detecting device comprising:
-
frequency analyzing means for calculating the power spectrum of an input speech signal; contrast enhancing means for enhancing the contrast between a local maximum portion and a local minimum portion in said power spectrum of said input speech signal; dividing means for dividing the power at each frequency band of said power spectrum enhanced by said contrast enhancing means by the power of said input speech signal in the corresponding frequency band; threshold value judging means for comparing a divisional result obtained by said dividing means with a single threshold value in each frequency band and for judging a frequency band corresponding to said divisional result to be a formant if said divisional result exceeds said threshold value.
-
-
9. A speech processing apparatus comprising:
-
frequency analyzing means for calculating the power spectrum of an input speech signal; contrast enhancing means for enhancing the contrast between a local maximum portion and a local minimum portion in said power spectrum of said input speech signal; threshold value judging means for comparing the power in the power spectrum enhanced by the contrast enhancing means with a single threshold value in each frequency band and for judging a frequency band corresponding to said power to be a formant if said power in the enhanced power spectrum exceeds said threshold value; gain value assigning means for assigning a first gain value to said frequency band judged to be a formant by said threshold judging means and for assigning a second gain value to other frequency bands; and speech signal generating means for generating a speech signal having a power spectrum obtained by multiplying the power at each frequency band of said power spectrum of said input speech signal by the gain value assigned to that frequency band by said gain value assigning means. - View Dependent Claims (10, 11, 12, 13)
-
-
14. A speech processing apparatus comprising:
-
frequency analyzing means for calculating the power spectrum of an input speech signal; contrast enhancing means for enhancing the contrast between a local maximum portion and a local minimum portion in said power spectrum of said input speech signal; dividing means for dividing the power at each frequency band of said power spectrum enhanced by said contrast enhancing means by the power of said input speech signal in the corresponding frequency band; threshold value judging means for comparing a divisional result obtained by said dividing means with a single threshold value in each frequency band and for judging a frequency band corresponding to said divisional result to be a formant if said divisional result exceeds said threshold value; gain value assigning means for assigning a first gain value to said frequency band judged to be a formant by said threshold judging means and for assigning a second gain value to other frequency bands; and speech signal generating means for generating a speech signal having a power spectrum obtained by multiplying the power at each frequency band of said power spectrum of said input speech signal by the gain value assigned to that frequency band by said gain value assigning means.
-
Specification