Thirteen manuscripts and extended reports on the nature of speech, instrumentation for its investigation, and practical applications of research are presented in this status report on speech research for the period of July-December 1979. The topics dealt with include speech perception, children's memory for sentences and word strings in relation to reading ability, influence of preceding fricative on stop consonant perception, electromyographic study of the jaw muscles during speech, laryngeal activity in Swedish voiceless obstruent clusters, laryngeal adjustments in the production of consonant clusters and geminates in American English, lexical tone and sentence prosody in Thai, influence of vocalic environment on perception of silence in speech, stimulus dominance and ear dominance in fused dichotic speech and nonspeech stimuli, use of feedback in established and developing speech, and brain lateralization in two-, three-, and four-month-old children for phonetic and musical timbre discriminations under memory load. (FL)