OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

July 9, 1993

A. Munson Fuller, M.D., F.A.C.S.
Tulsa Otolaryngology, Inc.
St. John Medical Center
Physicians Building
Suite 100
1725 East 19th Street
Tulsa, Oklahoma 74104

Dear Dr. Fuller:

This is in response to your letter of May 11, concerning hearing impairment, and confirms the information you previously received by telephone from this office.

You requested the recommended method for calculating the percent of impairment. The Occupational Safety and Health Administration (OSHA) does not have a method. Appendix F to the occupational noise exposure standard (29 CFR 1910.95) contains tables for making age adjustments to thresholds of hearing, but OSHA intends these adjustments to be used for determining age-corrected threshold shifts in hearing, not for calculating the percent of hearing impairment, which is not specifically addressed in the standard.

We suggest that you contact the State workers' compensation office for the recommended method for calculating the percent of impairment.

We appreciate the opportunity to clarify this matter for you.


Ruth McCully, Director
Office of Compliance Assistance

May 11, 1993

OSHA Office of Health Standards


When there has been a occupational noise induced hearing loss. What method does the Federal Register recommend to calculate the percent of impairment? What frequencies are used?


A M Fuller MD