Design of an Automatic Octave Sound Analyzer and Recorder
Abstract
An automatic octave sound apparatus is described which is suitable for analyzing and measuring sound in combat vehicles. An Ra-277 G sound frequency analyzer when used with a suitable graphic level recorder, permitted analysis of noise over a frequency range from 40 to 10,000 cycles per second by means of a 5-cycle wide or 200-cycle wide band pass filter. It was learned that airplane noise was produced by the propeller, by the engine exhaust, and by air leaks and aerodynamic flow. A complete system composed of a dynamic microphone, an octave band-pass filter set, a sound level meter, an automatic graphic level recorder, a battery power supply, and a hand-held remote control unit is described that determines either manually or automatically, sound levels in airplanes by octave bands.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 21, 1942
- Accession Number
- ADA801483
Entities
People
- H. W. Rudmose
- Hans F. Dienel
- Harold L. Ericson
Organizations
- Harvard University