Defense Health Agency - April 2023
Significant updates to the Department of Defense Instruction 6055.12
“Hearing Conservation Program”.
The significant change is a new requirement for initial hearing protector fit-testing to be conducted for all DOD personnel who have documented noise exposure greater than or equal to 95 dBA 8-hour time-weighted average (TWA) and who are enrolled in a service hearing conservation program (HCP).
What is Hearing Protector Fit Testing?
Hearing protector fit testing is a procedure used to quantitively measure the amount of noise reduction a specific hearing protector is providing a user. Fit testing measures the personal attenuation rating (PAR) specific to each individual ear and hearing protector. The PAR is a real-world measurement of the overall attenuation the hearing protector provides the individual’s ear.
Who receives fit-testing and when?
95dBA 8-hour TWA
All DOD personnel enrolled in their service HCP and exposed at or above 95 dBA 8-hour TWA will have a hearing protector fit-test at the initial reference audiogram or prior to initial duty in hazardous noise areas or as soon as possible after employment begins.
Significant Threshold Shift (STS)
When a positive Significant Threshold Shift (STS) is identified on the periodic audiogram. A hearing protector fit test will be used to evaluate the hearing protection devices, confirm adequacy of fit, and PAR for the noise environment.
Changes to a persons ear
When physical changes to a person’s ear canal cause poor fit of assigned hearing protection devices.
Fitted Hearing Protection Device
If the primary type of fitted hearing protection device is no longer available (e.g. employee switches from earplugs to ear muffs).
*Note: These are the minimum requirements for hearing protector fit-testing in the DOD—services may institute more stringent requirements for hearing protector fit-testing to better meet the needs of their respective HCP.
Single frequency shift
When a single frequency 15 dB shift at 1000, 2000, 3000, and 4000 Hz occurs.
