Noise reduction and communications in the CC 130 Hercules aircraft


  1. Bell, C.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN);Waterloo Univ, Waterloo ONT (CAN) Applied Health Sciences
The purpose of this project was to study was of creating a better acoustical environment for the crew of the Search and Rescue (SAR) CC 130 Hercules aircraft. The ultimate goals were to improve communications and reduce noise dosage, thus preserving hearing. Several commercial products were tested to assess their effectiveness in accomplishing the two outlined goals. The products included various Active Noise Reduction (ANR) Headsets, the Communication Ear Plug (CEP), and the standard issue Communications Headset. The Microphone In Real Ear technique was used in real human subjects to assess the amount of attenuation provided by each headset when exposed to 97 dB of mauve noise. A Kunov Mannequin, a binaural acoustic test fixture, was used to assess the amount of attenuation offered by the CEP in the same environment. Real human subjects were also subjected to the Modified Rhyme test in combination with the Maximum Likelihood Procedure to determine the signal to noise ratio required for each communications device to achieve a level of 60% speech intelligibility. Out of all the communications devices tested, the Sennheiser HMEC 222 and the CEP, worn in combination with the David Clark H10-76 provided the greatest amounts of noise attenuation. TRUNCATED
Report Number
DCIEM-TN-2001-006 — Technical Note
Date of publication
07 May 2001
Number of Pages
Hardcopy;Document Image stored on Optical Disk

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