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Evaluation of the annoyance due to helicopter rotor noise
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Author and Affiliation:
Sternfeld, H., Jr.(Boeing Vertol Co., Philadelphia, PA, United States);
Doyle, L. B.(Boeing Vertol Co., Philadelphia, PA, United States)
Abstract: A program was conducted in which 25 test subjects adjusted the levels of various helicopter rotor spectra until the combination of the harmonic noise and a broadband background noise was judged equally annoying as a higher level of the same broadband noise spectrum. The subjective measure of added harmonic noise was equated to the difference in the two levels of broadband noise. The test participants also made subjective evaluations of the rotor noise signatures which they created. The test stimuli consisted of three degrees of rotor impulsiveness, each presented at four blade passage rates. Each of these 12 harmonic sounds was combined with three broadband spectra and was adjusted to match the annoyance of three different sound pressure levels of broadband noise. Analysis of variance indicated that the important variables were level and impulsiveness. Regression analyses indicated that inclusion of crest factor improved correlation between the subjective measures and various objective or physical measures.
Publication Date: Jun 01, 1978
Document ID:
19780016960
(Acquired Nov 18, 1995)
Accession Number: 78N24903
Subject Category: ACOUSTICS
Report/Patent Number: NASA-CR-3001
Coverage: Final Report
Document Type: Technical Report
Publisher Information: NASA, Washington, United States
Contract/Grant/Task Num: NAS1-14192; RTOP 505-09-13-11
Financial Sponsor: NASA; United States
Organization Source: Boeing Vertol Co.; Philadelphia, PA, United States
Description: 74p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: AIRCRAFT NOISE; EFFECTIVE PERCEIVED NOISE LEVELS; HELICOPTERS; HUMAN TOLERANCES; NOISE INTENSITY; NOISE SPECTRA; PSYCHOACOUSTICS; ROTARY WINGS; SOUND PRESSURE
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