Test Procedures for the Evaluation of Helmet and Headset Mounted Active Noise Reduction Systems

Abstract

This report describes laboratory and field procedures appropriate for measuring the effectiveness of active noise reduction (ANR) devices mounted in flight helmets, armoured-vehicle crew helmets, communication headsets, and circumaural hearing protectors. The procedures described are: ear canal measurements using real subjects or an acoustic test fixture (ATF), masked- threshold and loudness-balance psychophysical procedures, a signal detection procedure, and speech reception procedures using modified rhyme and diagnostic rhyme test (MRT, DRT) and Speech Transmission Index (STI) measures. Keywords: Psychoacoustics; Speech intelligibility; Flight crews; Combat vehicle crews; Noise pollution.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1989
Accession Number
ADA212991

Entities

People

  • Julia M. Rylands
  • R. B. Crabtree
  • Stanly E. Forshaw

Organizations

  • DRDC Toronto

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Combat Vehicles
  • Communication Equipment
  • Detection
  • Ear
  • Earphones
  • Electronics
  • Electronics Laboratories
  • Frequency
  • Frequency Bands
  • Materials
  • Measurement
  • Microphones
  • Noise Reduction
  • Simulators
  • Sound Pressure
  • Speech
  • Test And Evaluation

Readers

  • Acoustics.
  • Aviation Science / Aeronautics.
  • Speech Processing/Speech Recognition.