NSC – Recording Criteria for Occupational Hearing Loss.

NSC – Recording Criteria for Occupational Hearing Loss.

(a) Basic requirement. If an employee’s hearing test (audiogram) reveals that a Standard Threshold Shift (STS) has occurred, you must record the case on the NSC 300 Log by checking the “hearing loss” column.

(b) Implementation.

(1) What is a Standard Threshold Shift?

A Standard Threshold Shift, or STS, is defined in the occupational noise exposure standard as a change in hearing threshold, relative to the most recent audiogram for that employee, of an average of 25 decibels (dB) or more at 2000, 3000, and 4000 hertz in one or both ears.

(2) How do I determine whether an STS has occurred?

If the employee has never previously experienced a recordable hearing loss, you must compare the employee’s current audiogram with that employee’s baseline audiogram. If the employee has previously experienced a recordable hearing loss, you must compare the employee’s current audiogram with the employee’s revised baseline audiogram (the audiogram reflecting the employee’s previous recordable hearing loss case).

(3) May I adjust the audiogram results to reflect the effects of aging on hearing?

Yes, when comparing audiogram results, you may adjust the results for the employee’s age when the audiogram was taken.

(4) Do I have to record the hearing loss if I am going to retest the employee’s hearing?

No, if you retest the employee’s hearing within 30 days of the first test, and the retest does not confirm the STS, you are not required to record the hearing loss case in Lotus Notes. If the retest confirms the STS, you must record the hearing loss illness within seven (7) calendar days of the retest.

(5) Are there any special rules for determining whether a hearing loss case is work-related?

Yes, hearing loss is presumed to be work-related if the employee is exposed to noise in the workplace at an 8-hour time-weighted average of 85 dBA or greater, or to a total noise dose of 50 percent. For hearing loss cases where the employee is not exposed to this level of noise, you must use the rules in 4.5 to determine if the hearing loss is work-related.

(6) If a physician or other licensed health care professional determines the hearing loss is not work-related, do I still need to record the case?

If a physician or other licensed health care professional determines that the hearing loss is not work-related or has not been significantly aggravated by occupational noise exposure, you are not required to consider the case work-related or to record the case on the in Lotus Notes.