Field study hearing protector evaluation procedure.
Authors
Rimmer TW
Source
NIOSH 2001 Dec; :1-69
Link
NIOSHTIC No.
20023747
Abstract
The Bone Conduction Loudness Balance (BCLB) method of measuring hearing protector attenuation was re-worked from earlier test versions and evaluated in a variety of situations, both laboratory and field. The procedure was implemented for running on any personal computer using the Windows operating system, and the protocol was simplified to emulate the standard hearing threshold test method. Laboratory testing using 26 previously inexperienced subjects showed that the revised procedure was easily implemented and more than twice as quickly done than the previous procedure, but was somewhat less consistent with the standard real ear attenuation at threshold (REAT) testing. Field hearing protection device (HPD) testing was evaluated with a total of 68 previously inexperienced subjects at four industrial sites. The mean time required for the BCLB test was about 6 minutes, and nearly all subjects were able to perform the test without difficulty, except for 2 of 68 who had too much hearing loss to hear the bone conduction reference sound at 200 Hz and one subject who was unwilling to learn the procedure. The primary difficulty was the tendency of some subjects to respond as in a threshold test, with re-instruction required for 17%. When used in a "candid" or unannounced test mode to evaluate HPD effectiveness as actually worn on the job, the procedure found attenuation values less than in a test setting, as was expected. The procedure was no more difficult to implement for candid testing than for other settings. The BCLB procedure was also used as part of an evaluation of the practicality and effect of using a HPD designed for better speech comprehension in noise (EAR UltraTech) with 21 hearing-impaired industrial subjects. Use of this HPD produced modest gains (mean improvement = 29%, p<0.01) in speech comprehension as measured by correct word identification on a 50-word test when compared with their normal HPD. However, 40% failed to wear the new HPD for extended testing due to discomfort and only 25% of those who did continue to wear it preferred it to their previous HPD.
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.