Abstract: A multi-part fixed codebook includes both individual fixed codebooks for each channel and a shared fixed codebook. Although the shared fixed codebook is common to all channels, the channels are associated with individual lags. Furthermore, the individual fixed codebooks are associated with individual gains, and the individual lags are also associated with individual gains. The excitation from each individual fixed codebook is added to the corresponding excitation (a shared codebook vector, but individual lags and gains for each channel) from the shared fixed codebook.

Abstract: A multi-channel linear predictive analysis-by-synthesis signal encoding method detects (S26, S27) inter-channel correlation and select one of several possible encoding modes (S24, S29, S30) based on the detected correlation.

Abstract: A multi-channel linear predictive analysis-by-synthesis signal encoding method detects (S26, S27) inter-channel correlation and select one of several possible encoding modes (S24, S29, S30) based on the detected correlation.

Abstract: A multi-part fixed codebook includes both individual fixed codebooks (FC1, FC2) for each channel and a shared fixed codebook (FCS). Although the shared fixed codebook (FCS) is common to all channels, the channels are associated with individual lags (D1, D2). Furthermore, the individual fixed codebooks (FC1, FC2) are associated with individual gains (gF1, gF2), and the individual lags (D1, D2) are also associated with individual gains (gFS1, gFS2). The excitation from each individual fixed codebook (FS1, FS2) is added to the corresponding excitation (a shared codebook vector, but individual lags and gains for each channel) from the shared fixed codebook (FCS).

Abstract: A speech quality estimation technique that employs an arbitrary, speech quality estimation algorithm. The speech quality estimation technique analyzes a reference speech signal and a test speech signal, and based on this analysis, identifies the level of continuous delay variation, if any, and the location of and size of any intermittent delay variations along the test signal. The reference speech signal and/or the test speech signal are adjusted to account for continuous delay variation and intermittent delay variations, such that the reference speech signal and the test signal are similarly scaled with respect to the time domain. The reference speech signal and the test speech signal are then compared for the purpose of generating a speech quality estimation. The resulting speech quality estimation is then adjusted based on the level of continuous delay variation and any intermittent delay variations.