Silent Playback and Public-Address System

The silent playback and public-address system provides a unique time-saving aid in photographing and recording dialog sequences having musical backgrounds. By means of a music- or speech-modulated 100-kilocycle transmitter, a supersonic-frequency magnetic field is generated throughout the scene area. The magnetic field includes secondary currents in concealed loops worn by the actors. These signals are demodulated in miniature batteryless units and energize small hearing-aid earphones. The earphones may be worn without concealment on distant and medium scenes. On close-ups the earphones are concealed and the sound is coupled to the ear through small plastic tubing camouflaged by make-up. Several types of loops, demodulators, and earphone units meet the varying needs of the scenes to be photographed and recorded. The stage microphone and sound-on-film recording channel is free from 100-kilocycle interference.

Print ISSN

0097-5834

Published

1949-03

Content type

Original Research

DOI

10.5594/J12531