Melissa Redford

The title of this project, "14 phonemes per second", refers to the speed at which adults speak. The number was first put forward by Lenneberg (1967), and has come to stand for the marvelous and intriguing complexity of speech production. The proposed project is to provide a book-length account of speaking that ties the representations guiding speech movement to speech motor skills, planning routines to cognitive processes, and speaking to language. The hypothesis is that the representations and routines that govern speaking emerge with communicative goal achievement over developmental time, where goal achievement is constrained by changing speech motor and cognitive skills.

The foundation for the proposed book is an informal model of speech-language production described in a manuscript written for a special issue of the "Journal of Phonetics" on the cognitive nature of speech sound systems. The model assumes that fluent speech production is guided by schemas, which are temporally structured sequences of remembered action and their sensory outcomes. The hypothesis is that these are formed when a speaker has successfully achieved a communicative goal. In early acquisition, schemas are coextensive with proto-words and the accompanying intonational patterns. Later they are words, collocations, and, under some circumstances, whole constructions (e.g., idioms). Thus, schemas represent action patterns associated with any unit of linguistic meaning.

Once acquired, schemas provide abstract programs for production. These are activated or inhibited via the linked goals. Control via communicative goals captures the intentional and automatic aspects of speech-language production. Goals are subject to conscious inspection; schemas are not. Control via communicative goals means that schemas are activated and executed as holistic units. Goals and linked schemas are defined by the language acquisition process. This process allows for the emergence of hierarchically structured speech plan representations.

The work will draw from a variety of literatures, including the literature on non-language motor skill acquisition and control, speech motor skill development, memory and planning in language production, the development of relevant cognitive processes, language acquisition, and linguistic theory. The goal is to arrange the findings from disparate fields into a coherent account of speaking that is psychologically plausible, developmentally sensitive, and computationally implementable.