A brief outline of the mechanism of speech production is given. It is shown that the motion of the articulators is encoded in changes in the spectra of speech waveforms. Parameters derived from these spectra form the basis of a method of speech synthesis. The perception of speech is seen as a decoding of the acoustic features of the speech wave. The organs of the hearing system which are involved in this process are briefly described. An attempt is made to relate the results of auditory psychophysics to the physiology of the hearing mechanism. The acoustic features which are relevant for the perception of the various classes of speech sounds are described. These have mostly been obtained by experiments involving synthesized speech. Finally the results of some experiments in dichotic listening are presented which emphasize the differences in the perception of speech and other sounds.