NOISE ATTENUATION CHARACTERISTICS OF A UNIVERSAL INSERT TYPE PERSONNEL NOISE PROTECTIVE DEVICE.
Abstract
An evaluation was made as to the tone-noise-speech attenuation characteristics of the Mine Safety Appliance Company MSA-3A universal insert noise protective device. Two general types of measures were obtained: (1) Physical measures from the output of a miniature condenser microphone mounted as an artificial ear within a plaster manikin head; and (2) Listener-observer judgments of threshold shift, device out versus device in place, as the stimuli were presented ambiently to 10 individuals. These judgments were made concerning: (a) pulsed pure tone at eight descrete frequencies (b) pulsed wide-band and octave-bands of noise, and (c) Spondee word threshold shifts. As measured by the artificial ear the MSA-3A does not afford as much attenuation as does the V-51R. Contrarily, the relative threshold shift judgments made concerning the three listening tasks yielded higher attenuation values for the MSA-3A than for the V-51R evaluated earlier. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1957
- Accession Number
- AD0622063
Entities
People
- Gilbert C. Tolhurst
Organizations
- Ohio State University