The perception of speech and non-speech complex sounds, for a variety of listeners including normal-hearing and hearing-impaired listeners, younger and older listeners, native and non-native listeners, listeners with normal and impaired musical perception, children with normal and disordered speech and hearing functions, auditory model for speech processing, and speech synthesis and recognition. Recent studies have been focusing on vowel formant discrimination, vowel identification, spectral enhancement, speech learning for non-native speakers, auditory models of speech processing for normal-hearing and hearing-impaired listeners and auditory processing for young children.