| 摘要 |
<p>In performing, for example, code excited linear prediction (CELP) coding, a linear predicting code (LPC) analyzing circuit (12) extracts an α-parameter from the inputted sound signals and an α-LSP converting circuit (13) converts the α-parameter into a line spectrum pair (LSP) parameter. Then an LSP vector quantizer (14) quantizes the line spectrum pair (LSP) parameter vector. In this case, the quantization characteristic can be improved without increasing the transmission bit rate by controlling a switch (16) in accordance with the value of the pitch detected by means of a pitch detecting circuit (22), and by selectively using either a code book (15M) for male voice or a code book (15F) for female voice.</p> |
