Accession Number : AD0691107

Title :   ACOUSTIC NOISE MEASUREMENTS UNDER FREE-FIELD CONDITIONS.

Descriptive Note : Research and development technical rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s) : Shapiro,Stuart J. ; Guazzoni,Guido E.

Report Date : JUN 1969

Pagination or Media Count : 24

Abstract : There is an increasing requirement by the field forces for new power source systems which operate silently. A method is described for the determination of equipment acoustic noise by octave-band analysis under free-field conditions. A procedure based on critical band theory is discussed for the establishment of masked threshold criteria to evaluate equipment sound pressure levels (SPL). Preferred octave-band spectra are given in terms of 20-foot sound pressure levels which correspond to the 'just audible' noise for listeners at 50 and 100 feet for a jungle environment. (Author)

Descriptors :   (*BATTERY CHARGERS, *NOISE), ARMY EQUIPMENT, POWER SUPPLIES, PRESSURE, JUNGLES, THERMOELECTRICITY

Subject Categories : Electric Power Production and Distribution
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE