Now Hear This! Preserve Employee Hearing and Save

To avoid employee hearing loss and the inevitable costs, Theresa Y. Schulz, PhD, suggests looking at indicators for hearing loss. For example:

• Standard Threshold Shift (STS): A 10 decibel (dB) average change in hearing at 2, 3, 4 kHz as compared to baseline (lagging indicator)
• Temporary Threshold Shift (TTS): An STS that recovers when the audiogram is repeated when employee is noise free for 14 hours (leading indicator)
• OSHA Recordable Hearing Loss: STS that results in mild hearing impairment (thresholds at 2, 3, 4 kHz or 25 dB) (very lagging indicator)
• Dosimetry: Noise exposure measure around the employees hearing area (around the ear) (leading estimate of exposure)
• In Ear Dosimetry: Protected noise exposure measured inside the hearing protector (leading measure of true exposure)
• Personal Attenuation Rating (PAR): Personal level of protection provided by a given earplug (leading indicator of protection provided by earplug)
• Hearing Loss Compensation: Damages paid to employee for noise induced hearing loss (very lagging indicator).

Audiometric Exams

Audiograms are another way to prevent employee hearing loss.
OSHA regulations require that employees whose noise exposures exceed an average of 85 dB over 8 hours must participate in a hearing conservation program. As a participant in this program employees must receive a baseline and annual audiogram.
Audiometric exams accurately measure hearing ability in each ear and detect the threshold for hearing different frequencies of sound—typically 500; 1,000; 2,000; 3,000; 4,000; and 6,000 Hz.
The measured hearing thresholds are compared with previous audiograms to determine if a threshold shift, or a loss of hearing, has occurred.

• An employee will be considered to have a hearing loss if he or she experiences an STS during an annual audiogram. STS or hearing loss may be slight, moderate, or severe.
• An employee will be found to have an STS if his or her threshold for hearing has increased an average of 10 dB or more at 2,000; 3,000; and 4,000 Hz in either ear from the baseline audiogram.

Based on the results of an audiometric exam, you may need to change the type of hearing protection an employee wears to provide more protection. And since hearing loss may also be attributed to other medical conditions (such as the use of medication or a recent injury), a further medical evaluation may be required.