ELECTRICAL AUDIO SIGNAL PROCESSING AND MONITORING METHODS AND DEVICES, NAMELY SOUND LEVEL METERS AND COMPUTER PROGRAMS FOR ANALYZING AND CLASSIFYING THE VOLUME AND FREQUENCY CONTENT OF FILM SOUNDTRACKS AND ELECTRICAL SWITCHES FOR CINEMA PROJECTORS, USED TO REDUCE THE PERCEIVED SOUND LEAKAGE BETWEEN AUDITORIUMS IN MULTIPLEX CINEMA THEATERS
Electrical and Scientific Apparatus