We present two speech transformation approaches designed to increase the intelligibility of speech. The first approach is used in the context of increasing the intelligibility of conversationally spoken speech for hearing-impaired listeners. An initial experiment showed that a relatively simple mapping function can map spectral features of conversationally spoken speech closer to context-equivalent spectral features of clearly spoken speech. The second approach aims to increase the intelligibility of speaking-impaired individuals by the general population. Results of listening tests indicated that although an intelligibility increase was not achieved, listeners preferred the transformed speech of the proposed system over that of an alternative system.
Alexander Kain, Jan P. H. van Santen