The dominant trend in phonetics today--due to a large extent to generative phonology--is to discover the brain mechanisms underlying the observed behavior in speech. Among other things there is interest in attempting to find out how motor programs are stored latently, selected, activated into muscular contractions, controlled, and tailored for optimum communication. Chapter 1 discusses research thought and methodology in phonetics and expresses the need for constant empirical feedback in all stages of the development of models of these processes. Chapter 2 attempts to shed light on the mechanisms speakers use to control the fundamental frequency of phonation in speech. Chapter 3 considers arguments, evidence, and experimental techniques relevant to discovering certain possible brain mechanisms underlying observed speech behavior. Two issues are covered: the possible role of feedback in speech and how the timing of gestures in speech is controlled. (Author/VM)