He was one of the creators of the experimental Yorktalk non-segmental speech synthesis system which employed techniques of Firthian Prosodic Analysis (FPA), an approach to phonology developed by J.R. Firth and members of the London School of linguistics. His book Doing Phonology written with John Kelly provides a radical contemporary take on FPA. Arising out of work which combined detailed phonetic analysis and Conversation Analysis (French and Local 1983) his recent research has explored the interactional functioning of phonetic detail and phonetic variation in talk-in-interaction (Local and Walker 2005).