mutism
n. lack or absence of speaking due to physical or psychogenic factors. The condition may result from a structural defect in the organs necessary for speech, congenital or early deafness in which an individual’s failure to hear spoken words inhibits the development of speech, neurological damage or disorder, psychological disorders (e.g., conversion disorder, catatonic schizophrenia), or severe emotional disturbance (e.g., extreme anger). The condition may also be voluntary, as in monastic vows of silence or the decision to speak only to selected individuals. See also akinetic mutism; alalia; selective mutism; stupor.