US 5,630,012 A · Speech efficient coding method

Abstract

There is provided a speech efficient coding method applicable to, e.g., analysis by a synthesis system such as an MBE vocoder, and comprising the steps of (a) dividing an input speech signal into block units on a time base, (b) dividing signals of each of the respective divided blocks into signals in a plurality of frequency bands, (c) discriminating whether signals of each of the respective divided frequency bands which are lower than a first frequency are voiced sound or unvoiced sound, (d) if the discrimination results in step (c) for a predetermined number of frequency bands is voiced sound, assigning a discrimination result of voiced sound to all frequency bands lower than a second frequency which is higher than the first frequency to obtain an ultimate discrimination result of voiced sound/unvoiced sound. Thus, even in the case where the pitch suddenly changes, or the harmonics structure is not precisely in correspondence with an integer multiple of the fundamental pitch period, a stable judgment of V (Voiced Sound) can be made.

Claims18

Dependent claims

An efficient speech coding method comprising the steps of:

dividing an input speech signal into a plurality of signal blocks in the time domain;
dividing each of the signal blocks into a plurality of frequency bands in the frequency domain;
determining spectrum structures of the frequency bands on the lower frequency side;
and
deciding that the signal components in the frequency bands on the higher frequency side are voiced sound components or unvoiced sound components in accordance with the determination in the preceding step.

2 more elements

Dependencies are inferred from the claim text.

Speech efficient coding method

Life of this patent

Speech efficient coding method

Life of this patent

Abstract

Claims18