Speech recognition under the noisy environment using improved emphasis method of spectral envelope

摘要

In this report, improved emphasis method of the -peaks of spectral envelopes is applied to speech recognition problem under the noisy environment. Former experiments have shown that emphasis of spectral peaks or modification of spectral envelope is effective for noisy speech recognition. However, the effectiveness of these methods are limited. In this experiment, threshold functions used in the emphasis method are changed. And the method of warping frequency axis is also used. Using these combined methods, the performance of recognition system under the noisy environment is improved, Especially, these methods are effective in case that the background noise is colored, The recognition rate is improved about 10% in case where the background noise is automobile noise.