The effect of a headset leakage on speech intelligibility in helicopter noise

Aviat Space Environ Med. 1996 Nov;67(11):1034-8.


Introduction: Speech intelligibility tests in recorded helicopter noise were performed on 10 subjects with normal hearing, using a Peltor aviation headset. The subjects acted as their own controls, a pair of sunglasses being the only variable factor.

Methods: Noise levels were also measured at the tympanic membrane in one of the test subjects for 7 consecutive fittings of the headset, with and without glasses.

Results: Results showed a substantial decrease in speech intelligibility when wearing glasses, being most marked for critical signal-to-noise ratios and the most difficult speech material. Changes were statistically highly significant. Average speech intelligibility scores decreased from 68% to 29% for one-syllable words when wearing glasses at critical signal-to-noise ratios. Noise measurements at the tympanic membrane in one subject showed a low-frequency leakage varying between consecutive fittings.

Conclusion: Our findings show that even small leakages due to fitting of the headset or helmet should be avoided, particularly in noisy aircraft with communication-demanding mission profiles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aircraft / instrumentation*
  • Auditory Threshold / physiology
  • Communication*
  • Ear Protective Devices / standards*
  • Equipment Failure
  • Evaluation Studies as Topic
  • Female
  • Humans
  • Male
  • Noise / adverse effects*
  • Noise, Occupational
  • Speech Perception / physiology*
  • Task Performance and Analysis*