ENCLOSURE FOR LOW-FREQUENCY ASSESSMENT OF ACTIVE NOISE REDUCING CIRCUMAURAL HEADSETS AND HEARING PROTECTORS

Authors

  • J.G. Ryan Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario, K1A 0R6
  • E.A.G. Shaw Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario, K1A 0R6
  • A.J. Brammer Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario, K1A 0R6
  • G. Zhang Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario, K1A 0R6

Abstract

Active Noise Reduction (ANR) technology is currently being employed in commercially available communication headsets, ANR is most effective at frequencies below 1 kHz and complements the passive attenuation characteristics of conventional circu- maural earcups. Commonly used acoustic test fixtures (such as KEMAR), however, fail to provide sufficient sound isolation of the measuring microphone below 100 Hz for measuring the performance of these devices. This can produce erroneous measurements of sound transmission. Even if adequate isolation could be achieved, there would remain the problem of generating a high-intensity sound field within a room at low frequencies. To overcome these difficulties, an acoustic test cell has been designed for measuring the performance of ANR circumaural headsets and hearing protection devices (HPDs) at frequencies below 1000 Hz.

Downloads

Published

1993-12-01

How to Cite

1.
Ryan J, Shaw E, Brammer A, Zhang G. ENCLOSURE FOR LOW-FREQUENCY ASSESSMENT OF ACTIVE NOISE REDUCING CIRCUMAURAL HEADSETS AND HEARING PROTECTORS. Canadian Acoustics [Internet]. 1993 Dec. 1 [cited 2021 Oct. 20];21(4):19-20. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/820

Issue

Section

Proceedings of the Acoustics Week in Canada