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.

June 18, 1985

Mr. Lawrence A. Vassallo
Data Processing Manager
Director of Training
Hearing Conservation Noise Control, Inc.
1721 Pine Street
Philadelphia, Pennsylvania 19103

Dear Mr. Vassallo:

This is in response to your letter of March 7 concerning audiograms conducted in accordance with the hearing conservation amendment, 29 CFR 1910.95 (c)-(p). We wish to inform you that the Occupational Safety and Health Administration (OSHA) resumed enforcement of the hearing conservation amendment on April 15, 1985.

Provision 29 CFR 1910.95(g)(7)(ii) allows but does not require an audiometric retest within 30 days in the event that the annual audiogram shows that an employee has suffered a standard threshold shift. An employer wishing to retest under these conditions may consider the retest audiogram as the annual audiogram. Therefore, if a valid retest audiogram does not show that the employee has suffered a standard threshold shift, no follow-up procedures need be implemented. This provision permits employers and the audiologists, otolaryngologists, or physicians who direct their audiometric testing programs to decide, on a case-by-case basis, whether a retest audiogram is necessary or desirable.

You related that occasionally an annual audiogram will show that an employee has suffered a standard threshold shift in only one ear, but that when a retest is done, the second audiogram will show a standard threshold shift in the second ear, as well as confirm the standard threshold shift in the first ear. In such a situation, OSHA requires that the second audiogram be treated as providing the annual audiometric test results for both ears. The employee must be notified that there is a standard threshold shift of hearing in both his/her ears.

Before a baseline audiogram may be revised due to a standard threshold shift, the shift must be persistent in the judgment of the professional evaluating the audiograms. In the situation you related, perhaps there is sufficient information for the professional evaluating the audiograms to make a judgment about the persistency of the standard threshold shift in the first ear, but there is probably not enough information for the professional to make the judgment call for the second ear. If, in fact, in the judgment of the professional evaluating the audiograms, the standard threshold shift in the first ear is persistent, but the persistency of the shift in the second ear is inconclusive, then the baseline audiogram may be revised for the first ear, but it may not be revised for the second ear.

Thank you for bringing your question to us. If we can assist you again, we shall be glad to do so.


John B. Miles, Jr., Director
Directorate of Field Operations

March 7, 1985

Mr. John B. Miles, Jr.
Director, Field Operations
Occupational Safety and Health Administration
200 Constitution Ave., N.W.
Washington, D.C. 20210

Dear Mr. Miles:

Our company is a consultant to industry regarding occupational hearing conservation. Even though the Amendment has been remanded, we continue to evaluate audiograms for standard threshold shift as detailed in the hearing conservation amendment to the OSHA noise standard.

Many of our clients conduct a thirty (30) day retest upon being notified by us that an OSHA standard threshold shift has occurred. This 30 day retest is again evaluated by us to determine if the shift is confirmed or is no longer present (we call it "shift repealed"). In many instances, a confirmed shift is in one ear. In conjunction with the confirmed shift in one ear, there may now also be a new OSHA shift in the other ear (quite frequently this new shift is the result of only a 5 dB change at one frequency that brings the average at 2000, 3000 and 4000 Hz to 10 dB). In any case, this new OSHA shift theoretically requires another 30 day retest.

In effect then, the employee described in the above situation will have been tested three times in approximately two months. That is, the routine annual test, the first 30 day retest and second 30 day retest. It is at this point that plant managers, plant physicians and others raise questions.

Our question to you concerning the situation presented above is what is OSHA's position concerning the second OSHA shift? Would it be satisfactory for the employer to notify the employee of the confirmed shift and for the baseline to be changed at that time to the last test? This in effect would disregard the second OSHA shift but the primary requirements would have been met. That is, the employee was notified and all educational counselling of the employee conducted as required.

On the assumption that OSHA's appeal will be successful, we would appreciate an official ruling of OSHA's position in this matter.


Lawrence A. Vassallo