McClelland and Elman originally implemented TRACE as a C program that has been the basis of all TRACE research to date. It is widely demonstrated that sources of information (acoustic signals, semantic context, etc.) are used to recognize words and the phonemes they contain. Indeed, as Cole and Rudnicky (1983) noted, these basic facts were described in Bagley's (1900) early experiments over 80 years ago. Cole and Rudnicky pointed out that the Trace model work has added clarity of detail to these basic findings, but has not produced a theoretical synthesis that provides a satisfactory account of these and many other fundamental aspects of speech perception. The Trace model approach arose from a number of initial ideas, some coming primarily from research into spoken language recognition (Marslen-Wilson) and Welsh, 1978; Morton,1969; Reddy,1976) and others deriving from more general considerations on interactive parallel processing (Anderson,1977; Grossberg, 1978; McClelland ,1979 )