The performance of a 4.6 kb/s CELP (code-excited linear prediction) speech coder has been investigated by using almost stationary speech sources. The results show that quantization of voiced phones produces much more audible noise than that of unvoiced ones. Investigations using spectral analysis lead to the conclusion that a considerable part of the noise is caused by degradation of fine structure information. The performance of the long-term prediction is severely influenced by the quantization of the short-term prediction parameters. Some strategies for improving coder performance are discussed.
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机译:已经通过使用几乎固定的语音源研究了4.6 kb / s CELP(码激励线性预测)语音编码器的性能。结果表明,有声电话的量化比无声电话的量化产生更多的可听噪声。使用频谱分析的研究得出的结论是,噪声的很大一部分是由精细结构信息的退化引起的。长期预测的性能受到短期预测参数量化的严重影响。讨论了一些提高编码器性能的策略。
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