acoustic feature

A characteristic of a speech sound when analyzed in physical terms, e.g. FUNDAMENTAL frequency, amplitude, harmonic structure. Such analyses are provided by ACOUSTIC PHONETICS, and it is possible to make acoustic classifications of speech sounds based upon such features, as when one classifies VOWELS in terms of their FORMANT structure. The acoustic properties of a sound which aid its identification in speech are known as acoustic cues. In the DISTINCTIVE FEATURE theory of PHONOLOGY of Jakobson and Halle (see JAKOBSONIAN), acoustic features are the primary means of defining the BINARY oppositions that constitute the phonological SYSTEM of a language.