The name of an acoustically based binary feature, originally introduced by Jakobson, Fant & Halle (1952). Acute sounds have a concentration of energy in the higher frequency regions of the spectrum. Typical examples of [+acute] sounds are front vowels, dental, alveolar and palatal consonants. These sound classes all also share the articulatory feature of being produced with a constriction in the middle (front to back) of the vocal tract. The opposite of acute is grave.
Jakobson R., Fant G. & Halle M. (1952) Preliminaries to speech analysis M.I.T.