Record Details
| Evaluation of the annoyance due to helicopter rotor noise | |||||||
| NTRS Full-Text: | Click to View [PDF Size: 2.3 MB] | ||||||
| Author and Affiliation: |
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| 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)
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| 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: | HELICOPTERS; HUMAN TOLERANCES; NOISE INTENSITY; ROTARY WINGS; AIRCRAFT NOISE; EFFECTIVE PERCEIVED NOISE LEVELS; NOISE SPECTRA; PSYCHOACOUSTICS; SOUND PRESSURE | ||||||
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