This report is one of a regular series on the status and progress of studies on the nature of speech, instrumentation for its investigation, and practical applications. Drawn from the period of January 1 to March 31, 1980, the 14 manuscripts cover the following topics: (1) acoustics in human communication; (2) motor-sensory feedback formulations; (3) phonetic representation and speech synthesis by rule; (4) relationships between speech perception and speech production in normal hearing and hearing impaired subjects; (5) accessibility of the voicing distinction for learning phonological rules; (6) the effect of vocalic context on fricative perception; (7) a vibratory systems analysis of human movement production; (8) perception of limb position; (9) perceiving phonetic segments; (10) reading, linguistic awareness, and language acquisition; (11) a range-frequency effect on perception of silence in speech; (12) perception of stop consonants before low unrounded vowels; (13) apractic syndromes; and (14) a comparison of parametric representations for monosyllabic word recognition in continuously spoken sentences. (FL)