Abstract
The speech comprehension for a hand-of-hearing person is far worse than a hearing-normal people under the noisy environment. In order to improve the speech perception under the noisy environment,the speech enhancement,namely the noise reduction,must be performed.This thesis employs the masking effect to the speech enhancement. After the noise is reduced,we use the equivalent rectangular bandwidth (ERB)scale and matching rounded exponential(ROEX) model to convert the speech in frequency domain.By doing so,we may help those hand-of- hearing persons in improving their speech perception.