The Phonetic feature of "emphasis" in Arabic involves (1) a narrowing in the back cavity caused by retracting and lowering the rest of the tongue and the epiglottis and an inward movement of the lateral walls of the pharynx, (2) a widening in the front cavity caused by lowering the body of the tongue in the mouth. Acoustically this results in F1 raising and F2 lowering; F0 has been found to be lower for the emphatic items than for the non-emphatic counterparts.