Record Details

Record 1 of 1
Laboratory studies of scales for measuring helicopter noise
NTRS Full-Text: Click to View  [PDF Size: 6.4 MB]
Author and Affiliation:
Ollerhead, J. B.(Wyle Labs., Inc., El Segundo, CA, United States)
Abstract: The adequacy of the effective perceived noise level (EPNL) procedure for rating helicopter noise annoyance was investigated. Recordings of 89 helicopters and 30 fixed wing aircraft (CTOL) flyover sounds were rated with respect to annoyance by groups of approximately 40 subjects. The average annoyance scores were transformed to annoyance levels defined as the equally annoying sound levels of a fixed reference sound. The sound levels of the test sounds were measured on various scales, with and without corrections for duration, tones, and impulsiveness. On average, the helicopter sounds were judged equally annoying to CTOL sounds when their duration corrected levels are approximately 2 dB higher. Multiple regression analysis indicated that, provided the helicopter/CTOL difference of about 2 dB is taken into account, the particular linear combination of level, duration, and tone corrections inherent in EPNL is close to optimum. The results reveal no general requirement for special EPNL correction terms to penalize helicopter sounds which are particularly impulsive; impulsiveness causes spectral and temporal changes which themselves adequately amplify conventionally measured sound levels.
Publication Date: Nov 01, 1982
Document ID:
19830003569
(Acquired Nov 13, 1995)
Accession Number: 83N11839
Subject Category: ACOUSTICS
Report/Patent Number: NASA-CR-3610, NAS 1.26:3610, WR82-12
Coverage: Final Report
Document Type: Technical Report
Publisher Information: NASA, Washington, United States
Contract/Grant/Task Num: NAS1-16276
Financial Sponsor: NASA; United States
Organization Source: Wyle Labs., Inc.; El Segundo, CA, United States
Description: 123p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: BLADE SLAP NOISE; EFFECTIVE PERCEIVED NOISE LEVELS; GRAPHS (CHARTS); HELICOPTERS; NOISE SPECTRA; NOISE TOLERANCE; PSYCHOACOUSTICS; RANKING; REGRESSION ANALYSIS; WEIGHTING FUNCTIONS
› Back to Top
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed
Find Similar Records
 
NASA Logo, External Link

NASA Official: Gerald Steeman
Sponsored By: NASA Scientific and Technical Information Program
Site Curator: NASA Center for AeroSpace Information (CASI)
Last Modified: August 29, 2013

Privacy Policy & Important Notices Disclaimers, Copyright, Terms of Use Freedom of Information Act USA.gov NASA.gov NASA OCIO Free Adobe PDF Reader Free MS Word Viewer