Breadcrumb Home > Dictionary > Index O optical sound: Meaning and Definition of Find definitions for: op'tical sound' Pronunciation: [key] — Motion Pictures. Motion Pictures. sound recorded on and subsequently played back from an optical or photographic soundtrack, as opposed to a magnetic soundtrack. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. optical scanning optical soundtrack TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: limpid Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language