optical sound

noun Movies.

sound recorded on and subsequently played back from an optical or photographic soundtrack, as opposed to a magnetic soundtrack.

Origin of optical sound

First recorded in 1930–35

Words nearby optical sound

optical pyrometer, optical resonator, optical rotation, optical scanner, optical scanning, optical sound, optical soundtrack, optical tooling, optical tweezers, optical wedge, optician

British Dictionary definitions for optical sound

optical sound

noun

sound recorded in the form of a photographic image on cinematograph films