Abstract A speech parameter encoder capable of encoding spectrum parameters at a bit rate of 1 kb/s or less with comparatively small amount of operations and memory capacity. A spectrum parameter calculation unit (130) derives a spectrum parameter representing the spectrum envelope of a discrete input speech signal through division thereof into frames each having a predetermined time length. A weighted coefficient calculation unit (150) derives a weighted coefficient corresponding to an auditory masking threshold value through derivation thereof from the speech signal. A spectrum parameter quantization unit (160) receives the weighted coefficient and the spectrum parameter and centeses the spectrum parameter through search of a codebook such as to minimize the weighting distortion based on the weighted coefficient.
A speech parameter encoder comprising: a spectrum parameter calculation unit for deriving a spectrum parameter representing the spectrum envelope of a discrete input speech signal through division thereof into frames each having a predetermined time length; a weighted coefficient calculation unit for deriving a weighted coefficient corresponding to an auditory masking threshold value through derivation thereof from the speech signal; and a spectrum parameter quantization unit for receiving the weighted coefficient and the spectrum parameter and quantizing the spectrum parameter through search of a codebook such as to minimize the weighting distortion based on the weighted coefficient.
Claim 2
Dependent Claim
39 words
The speech parameter encoder according to claim 1, wherein said weighted coefficient calculation unit includes a weighted coefficient calculation unit for deriving a weighted coefficient corresponding to an auditory masking threshold value through derivation thereof from the spectrum parameter.
Claim 3
Dependent Claim
34 words
The speech parameter encoder according to claim 1, wherein said spectrum parameter calculation unit includes a spectrum parameter calculation unit which makes non-linear transform of the spectrum parameter such as to meet auditory characteristics.
Claim 4
Dependent Claim
34 words
The speech parameter encoder according to claim 2, wherein the spectrum parameter calculation unit includes a spectrum parameter calculation unit which makes non-linear transform of the spectrum parameter such as to meet auditory characteristics.
Claim 5
Dependent Claim
35 words
The speech parameter encoder according to claim 1, wherein said spectrum parameter calculation unit performs a linear transform of the spectrum parameter such as to meet auditory sense characteristics before the quantization of spectrum parameter.
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