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Heat and humidity buildup under earmuff-type hearing protectors
1Division of Applied Research and Technology, National Institute for Occupational Safety and Health, Columbia Parkway, Cincinnati, OH 45226, USA. rrd1@cdc.gov
Noise & Health
|March 4, 2011
Summary
Comfort in earmuff hearing protection decreases with heat and humidity buildup. This study found that even low-exertion tasks can significantly impact the under-earmuff environment, affecting user comfort.
Area of Science:
- Occupational Health
- Biomedical Engineering
- Human Factors Engineering
Background:
- Earmuff-type hearing protectors are crucial for noise reduction but wearer comfort remains a significant challenge.
- Understanding the environmental factors within earmuffs is essential for improving their design and effectiveness.
Purpose of the Study:
- To investigate comfort indicators, specifically temperature and humidity, within earmuff hearing protectors during a low-exertion task.
- To compare the performance of two different measurement systems (Omega and iButton) for monitoring the under-earmuff environment.
- To assess the impact of the under-earmuff environment on skin surface pH and subjective comfort.
Main Methods:
- Twenty subjects wore earmuffs equipped with Omega and iButton temperature/humidity sensors during a 25-minute walking task.
- Temperature and humidity were recorded every 10 seconds; skin pH was measured pre- and post-task.
- Subjects provided subjective ratings of earmuff comfort.
Main Results:
- Earmuff comfort significantly decreased over the task duration.
- Both Omega and iButton systems yielded comparable temperature and humidity data, showing heat and humidity buildup.
- Skin pH showed a non-significant trend towards less acidity; iButton proved more robust despite limited gradations.
Conclusions:
- The under-earmuff environment, characterized by increasing heat and humidity, negatively impacts wearer comfort.
- Inexpensive tools and low-exertion tasks can effectively model the under-earmuff environment.
- Findings can inform the design of more comfortable and effective hearing protection devices.
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