/ Dictionary / Index S sound head: Meaning and Definition of Find definitions for: sound' head" Pronunciation: [key] — Motion Pictures. Motion Pictures. a mechanism through which film passes in a projector for conversion of the soundtrack into audio-frequency signals that can be amplified and reproduced. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sound film sound hole Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language