WORD SOUND DEAFNESS RESOLVED

This paper reports a longitudinal study of a patient (B.C.R.) who was initially diagnosed as 'pure word deaf' (word sound deaf). Her perform ance, and change over time, on tests of speech perception and environm ental sound discrimination are reported. The study demonstrates that r ecovery of word sound deafness can occur despite the presence of bilat eral lesions. B.C.R. performed abnormally in both auditory and visual time estimation tasks. We tentatively suggest that the slow operation of an 'internal clock' that regulates perception across modalities und erlies her difficulties. This clock may also regulate the timing of mo tor production (Ivry and Keele 1989) and thus account for the associat ion between word sound deafness and phonological errors in speech prod uction in all reported cases.