On the Importance of Phase in Human Speech Recognition

In this paper, the authors analyze the effects of uncertainty in the phase of speech signals on the word recognition error rate of human listeners. The motivating goal is to get a quantitative measure on the importance of phase in automatic speech recognition by studying the effects of phase uncertainty on human perception. Listening tests were conducted for 18 listeners under different phase uncertainty and Signal-to-Noise Ratio (SNR) conditions. These results indicate that a small amount of phase error or uncertainty does not affect the recognition rate, but a large amount of phase uncertainty significantly affects the recognition rate.