sibiláns
A sibilant is a speech sound produced by directing a stream of air from the lungs over the tongue and against the alveolar ridge or the teeth. These sounds are characterized by a hissing quality, which is why they are called sibilants. In English, the common sibilants are the /s/ sound, as in "sun," the /z/ sound, as in "zoo," the /ʃ/ sound (sh), as in "ship," the /ʒ/ sound (zh), as in "treasure," and the affricates /tʃ/ (ch), as in "church," and /dʒ/ (j), as in "judge." The distinction between these sounds is often based on whether they are voiced or voiceless. Voiceless sibilants like /s/, /ʃ/, and /tʃ/ are produced with the vocal cords not vibrating, while voiced sibilants like /z/, /ʒ/, and /dʒ/ involve vocal cord vibration. The exact articulation of sibilants can vary slightly between languages and dialects. Sibilants play a crucial role in the phonological system of many languages, contributing to the distinctiveness of words. Their acoustic properties, particularly their high-frequency energy, make them important for speech intelligibility.