The Enhancement of Speech Intelligibility in Wideband Noise

This report details the results of two studies involving speech mixed with additive white noise. The first study concerns the effects of high-pass and low-pass filtering upon the intelligibility of speech in noise. This study provided basic perceptual data concerning the speech in noise situation. The second study concerns the development of a method for processing speech mixed with noise to result in an enhancement of its intelligibility. While several processing methods were implemented, the method explored in greatest detail was based upon a combination of a spectral subtraction method and a pitch tracking method. The final intelligibility results obtained using the method did not show that it resulted in an intelligibility enhancement over unprocessed speech in noise. However, the results are very enlightening regarding this speech in noise problem. In addition, it is the author's belief that the basic processing method has significant potential for enhancing the intelligibility of speech in noise. (EDC)