Accession Number : ADD009356

Title :   Automatic Volume Control System.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Humphrey,Francis S

Report Date : 15 Dec 1981

Pagination or Media Count : 5

Abstract : An automatic volume control system comprises a source for producing an audio signal; an amplifier responsive to a control signal for varying the amplitude of the audio signal, a transducer for converting the audio signal to sound energy, a detector for detecting the output of the transducer and ambient noise which interferes with comprehension of the sound energy, and a phase comparator connected to the detector and to the audio signal source for comparing the phases of the outputs thereof and for producing an output proportional to the level of detected ambient noise. The output of the phase comparator is connected as a control signal to the amplifier means so as to control the amplitude of the audio signal. (Author)

Descriptors :   *Patents, *Control systems, *Acoustic signals, Feedback, Ambient noise, Output, Gates(Circuits), Automatic, Loudspeakers, Control, Energy, Microphones, Sources, Comprehension, Transducers, Volume, Signals, Preamplifiers, Sound

Subject Categories : Electrical and Electronic Equipment
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE