Patent ID: 8438033
Filing Date: 2013-05-07
Classification: G10L

Abstract:
1. A voice conversion apparatus comprising: a parameter memory to store a plurality of target speech spectral parameters representing characteristics of voice quality of target speech; a voice conversion rule memory to store a voice conversion rule for converting voice quality of source speech into voice quality of the target speech; an extraction unit configured to extract, from an input source speech, a source speech spectral parameter representing a characteristic of voice quality of the input source speech; a parameter conversion unit configured to convert extracted source speech spectral parameter into a first conversion spectral parameter by using the voice conversion rule; a parameter selection unit configured to select at least one target speech spectral parameter similar to the first conversion spectral parameter from the target speech spectral parameters stored in the parameter memory; an aperiodic component generation unit configured to generate an aperiodic component spectral parameter representing an aperiodic component of voice quality from selected target speech spectral parameter; a parameter mixing unit configured to mix a periodic component spectral parameter representing a periodic component of voice quality included in the first conversion spectral parameter with the aperiodic component spectral parameter, to obtain a second conversion spectral parameter; and a speech waveform generation unit configured to generate a speech waveform from the second conversion spectral parameter, wherein the aperiodic component generation unit determines a boundary frequency between the periodic component and the aperiodic component of voice quality from one of the selected target speech spectral parameter and the first conversion spectral parameter, and extracts, from the selected target speech spectral parameter, the aperiodic component spectral parameter whose frequency band is higher than the boundary frequency.