NOISE ATTENUATION CHARACTERISTICS OF THE GENTEX-RCA X-1 AND THE RCA X-2 PERSONNEL NOISE PROTECTIVE DEVICES
Abstract
An evaluation was made as to the tone, noise, and speech threshold attenuation characteristics of the Gentex RCA X-1 and the RCA X-2 personnel noise protective devices, each tested with a liquid ear cushion and a foam rubber ear cushion. Two general types of measures were obtained: (1) physical measures taken from the output of a miniature condenser microphone serving as an artificial ear mounted within a plaster manikin head; and (2) listener-observer judgments of threshold shift, normal listening versus device over the ears, to the various stimuli presented ambiently to 10 individuals. The judgments included responses to: (a) pulsed pure tone at eight discrete frequencies, (b) pulsed wide-band and octave-bands of noise, and (c) Spondee words. Both the physical and the subjective related attenuation measures show that the RCA X-2, employing both ear cushions affords as much attenuation as, or more than, the V- 51R. The Gentex RCA X-1 was not so efficient as the V-51R at the lower frequencies or bands of noise but was for the higher frequency range.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 30, 1959
- Accession Number
- AD0622048
Entities
People
- Gilbert C. Tolhurst