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Effects of repetition rate and impulsiveness of simulated helicopter rotor noise on annoyanceAnnoyance judgements were obtained for computer generated stimuli simulative of helicopter impulsive rotor noise to investigate effects of repetition rate and impulsiveness. Each of the 82 different stimuli was judged at 3 sound pressure levels by 48 subjects. Impulse repetition rates covered a range from 10 Hz to 115 Hz; crest factors covered a range from 3.2 dB to 19.3 dB. Increases in annoyance with increases in repetition rate were found which were not predicted by common loudness or annoyance metrics and which were independent of noise level. The ability to predict effects of impulsiveness varied between the noise metrics and was found to be dependent on noise level. The ability to predict the effects of impulsiveness was not generally improved by any of several proposed impulsiveness corrections. Instead, the effects of impulsiveness were found to be systematically related to the frequency content of the stimuli. A modified frequency weighting was developed which offers improved annoyance prediction.
Document ID
Document Type
Technical Publication (TP)
Powell, C. A.
(NASA Langley Research Center Hampton, VA, United States)
Mccurdy, D. A.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 4, 2013
Publication Date
February 1, 1982
Subject Category
Environment Pollution
Report/Patent Number
Accession Number
Funding Number(s)
PROJECT: RTOP 505-35-13-01
Distribution Limits
Work of the US Gov. Public Use Permitted.
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