Noise-induced hearing loss is among the most frequently reported occupational diseases in Turkey. It is also the problem noticed latest in the field. The reason is simple. The loss causes no pain, does not start in one ear and first affects frequencies outside everyday speech. By the time the employee notices, the damage is usually permanent.
Why does the loss go unnoticed for years?
Noise damage typically starts in the high frequencies around 4000 Hz. Daily speech sits mostly between 500 and 2000 Hz. So the employee can talk on the phone, follow conversations and assume their hearing is fine. Once the loss reaches the speech frequencies there is no way back. That is why early diagnosis is only possible with regular audiometry follow-up.
What do the regulations require, and when?
The Regulation on the Protection of Workers from Noise-Related Risks builds obligations in steps based on exposure level. Three thresholds are defined for the daily noise exposure level.
- Lower action value 80 dB(A). The employer must make hearing protection available, and a hearing test is provided if the employee requests one.
- Upper action value 85 dB(A). Hearing protection becomes mandatory and regular audiometric follow-up is required.
- Exposure limit value 87 dB(A). This level must never be exceeded, taking the effect of hearing protection into account.
Read together with the general health surveillance duty in Article 15 of Law No. 6331, the picture is clear. In a noisy workplace audiometry is not an optional screening. It is a mandatory part of health surveillance.
What does proper audiometry follow-up look like?
The value of the measurement depends on standard conditions. The test should be performed in a soundproof booth, with a clinical audiometer holding a valid calibration certificate, covering 500 to 8000 Hz for both ears. Results are interpreted against previous audiograms, not in isolation. What matters most is the shift in thresholds rather than any single absolute value.
What happens when a loss is found?
An employee with a threshold shift is reported to the occupational physician. The physician requests an exposure review, hearing protection fit is checked and the employee may be moved to a less noisy position if needed. A shift caught early can be stopped with these measures. In advanced loss the goal is to protect the hearing that remains, not to recover what is gone.
If you want to set up comparative audiometry follow-up for your noisy site, send your headcount and shift pattern through the quote form. We will plan the measurements at your workplace with our soundproof mobile booth.