Accession Number : ADA139741

Title :   Active Noise Reduction,


Personal Author(s) : Carter,J

PDF Url : ADA139741

Report Date : Jan 1984

Pagination or Media Count : 39

Abstract : Active Noise Reduction (ANR) techniques, singly and in combination with passive hearing protectors, offer the potential for increased sound protection, enhanced voice communications and improved wearability features for personnel exposed to unacceptable noise conditions. An enhanced closed loop active noise reduction system was miniaturized and incorporated into a standard Air Force flight helmet (HGU-26/P). This report describes the theory of design and operation, prototype configuration and operation, and electroacoustic performance and specifications for the ANR system. This system is theoretically capable of producing in excess of 30 decibels of active noise reduction. Electroacoustic measurements on a flat palte coupler demonstrated approximately 20 decibels of active noise reduction with the prototype unit. A performance evaluation of the integrated ANR unit will be conducted under laboratory and field conditions by government personnel to determine the feasibility of the system for use in military applications. (Author)

Descriptors :   *Noise reduction, *Methodology, *Electroacoustics, *Ear protectors, *Voice communications, *Flight helmets, *Closed loop systems, Air Force equipment, Miniaturization, Prototypes, Configurations, Schematic diagrams, Charts, Hearing, Fabrication, Integration, Feasibility studies, Military applications

Subject Categories : Flight Control and Instrumentation
      Protective Equipment
      Voice Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE