The glottis is the part of the
larynx in which voice is produced. It consists of the true
vocal folds and the opening between them. Sounds whose production involves
only the glottis are called
glottal. English has a glottal
approximant spelt
h and in many accents of English the
glottal stop (made by pressing the glottal folds together) is used as a variant (
allophone) of the phoneme /t/.