diffuse (adj.) (diff, DIFF)

One of the features of sound set up by Jakobson and Halle in their DISTINCTIVE FEATURE theory of PHONOLOGY, to handle variations in PLACE OF ARTICULATION; its opposite is COMPACT. Diffuse sounds are defined ARTICULATORILY and ACOUSTICALLY, as those which involve a STRICTURE relatively far back in the mouth, and a relatively low concentration of acoustic energy in non-central parts of the sound spectrum. CLOSE VOWELS and FRONT CONSONANTS are [+diffuse] (abbreviated as [+diff]): MID or LOW vowels and PALATAL or VELAR consonants are [−diffuse] ([−diff]). This feature is replaced by HIGH in Chomsky and Halle’s system.