NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Characterization of Low Frequency Auditory FiltersThe purpose of this study is to characterize auditory filters at low frequencies, defined as below about 100 Hz. Three experiments were designed and executed. They were conducted in the Exterior Effects Room at the NASA Langley Research Center, a psychoacoustic facility designed for presentation of aircraft flyover sounds to groups of test subjects. The first experiment measured 36 subjects’ hearing threshold for pure tones (at 25, 31.5, 40, 50, 63 and 80 Hz) in “quiet” conditions. The subjects, male and female, had a wide age range. This experiment allowed the performance of the test facility to be assessed and also provided screened test subjects for participation in subsequent experiments. The second and third experiments used 20 and 10 test subjects, respectively, and measured psychophysical tuning curves (PTCs) that describe auditory filters with center frequencies of approximately 63 and 50 Hz. The latter is assumed to be the lowest (bottom) auditory filter; thus, sounds at frequencies below about 50 Hz are perceived via the lower skirt of this lowest filter. All experiments used an adaptive, three-alternative forced-choice test procedure using either variable level tones or variable level, narrowband noise maskers. Measured PTCs were found to be very similar to other recently published data, both in terms of mean values and intersubject variation, despite different experimental protocols, different test facilities, and a wide range in subjects’ age.
Document ID
20190001050
Acquisition Source
Langley Research Center
Document Type
Technical Memorandum (TM)
Authors
Rafaelof, Menachem (National Inst. of Aerospace Hampton, VA, United States)
Christian, Andrew W. (NASA Langley Research Center Hampton, VA, United States)
Shepherd, Kevin P. (NASA Langley Research Center Hampton, VA, United States)
Rizzi, Stephen A. (NASA Langley Research Center Hampton, VA, United States)
Stephenson, James H. (Army Aviation and Missile Research Development Engineering Center Hampton, VA, United States)
Date Acquired
February 28, 2019
Publication Date
January 1, 2019
Subject Category
Acoustics
Report/Patent Number
L-20983
NF1676L-31935
NASA/TM?2019-220120
Funding Number(s)
WBS: WBS 664817.02.07.03.02.03
Distribution Limits
Public
Copyright
Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available