BENEFIT OF ACTIVE NOISE REDUCTION TO NOISE EXPOSURE IN HIGH-RISK ENVIRONMENTS

Authors
  1. Crabtree, R.B.
  2. Rylands, J.M.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
Active Noise Reduction (ANR) is a technique for enhancing the low-and mid-frequency attenuation properties of the helmets and headsets used in noisy environments such as helicopters and tracked vehicles. The process involves sensing the noise field within the ear cup and re-introducing it into the cavity out of phase. Implementation of the ANR principle has been demonstrated to reduce noise exposure, to improve voice communication and to enhance the detection of auditory signals. DCIEM has developed a set of criteria against which helmet and headset mounted ANR systems may be evaluated. These include perceptive and objective measures of performance under a variety of conditions. A comparative study of several commercial systems is presented, in which real-ear objective and loudness balance subjective testing was carried out. The results show generally good agreement between two protocols, and confirm the potential for a useful reduction in the hearing damage risk associated with high-noise environments.
Report Number
DCIEM-92-12 — Reprint
Date of publication
01 Mar 1992
Number of Pages
4
DSTKIM No
94-00229
CANDIS No
136020
Format(s):
Hardcopy;Originator's fiche received by DSIS

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