Noise attenuation characteristics for supra-aural audiometric headsets using the models MX–41/AR and 51 earphone cushions

Abstract

Continuing problems with the consistency of the MX–41/AR earphone cushion’s physical and acoustical characteristics have led to the development of a one-piece cushion (model 51) by the Telephonics Corporation. The attenuation characteristics of this one-piece cushion have been measured according to ASA Standard 1–1975 (ANSI S3.19–1974) and are reported herein. The attenuation characteristics provided for the wearer by the model 51 cushions tend to be slightly greater than those of the MX–41/AR cushion but the differences are not generally significant, with α = 0.05.

Attenuation Provided by Four Different Audiometric Earphone Systems

“…The mean test attenuation values for the MX-4 1 /AR and P/N 5 1 cushions are shown in Table 6 along with the results of a similar study by Michael and Bienvenue (1981). The attenuation values obtained in the present study were lower for both the MX-41/AR and P/N 51 compared with the values reported by Michael and Bienvenue (198 1) at each frequency.…”

“…The mean test attenuation values for the TDH-49P/ MX-41JAR are shown in Table 5 along with attenuation values reported by Arlinger (1986), Berger and Killion (1989), Michael and Bienvenue (1981), Poulsen (1988) and Shipton (1983). Each study determined the attenuation provided by a TDH type earphone in a MX-4 1 /AR cushion in a diffuse sound-field using '/3 octave bands of noise according to a specified method (ANSI S3.19-1974(ANSI S3.19- , S12.6-1984IS0 4869-1981).…”

“…In the present study, the insertion depth was held constant so that the outer edge of the foam earplug was flush with the bowl (floor) of the concha. This insertion depth was chosen as a result of a pilot study where 20 everyday users of the ER-3A/ER3-14 were surveyed concerning the insertion depth that they used in Michael and Bienvenue (1981) and the difference between the MX-41/AR and the P/N 51 attenuation values for each study (in dB). practice.…”

“…The attenuation values obtained in the present study were lower for both the MX-41/AR and P/N 51 compared with the values reported by Michael and Bienvenue (198 1) at each frequency. In the Michael and Bienvenue (1981) study, the static force of each earphone cushion system was adjusted to about 450 g for each subject. Further, once the earphone cushion systems were fitted, the subjects adjusted them in a background of pink noise to obtain maximum subjective attenuation.…”

“…Even though several studies have reported the attenuation values provided by supra-aural earphone cushion systems, sound excluding earphone enclosures, and insert earphones with foam earplugs, many of these studies did not use Y3 octave bands of noise presented in a diffuse soundfield. Further, only one study (Michael & Bienvenue, 1981) has reported the attenuation provided by a TDH earphone in a P/N 5 1 cushion and some conflicting data has been reported about the attenuation provided by an insert earphone and foam earplug (Berger & Killion, 1989;Clark & Roeser, 1988). The purpose of this research was to determine the amount of attenuation supplied by TDH earphones in MX-4 1 /AR and P/N 5 1 cushions, Audiocup sound excluding earphone enclosures, and ER-3A insert earphones with ER3-14 foam earplugs using */3 octave bands of noise presented in a diffuse sound field.…”