Hearing Conservation


I get the best questions from employees as I’m setting them up to wear a dosimeter. (FYI- this does not really apply to sound level readings, only dosimetry)

  • Why do I have to wear the monitor (dosimeter)? Can’t we just place it in the middle of the area?

Ideally we want the dosimeter to measure the individual exposure. Many factors influence the average noise level, including work practices, location (sound bouncing & dampening), height, proximity to others, equipment, etc.

  • What is the dosimeter actually measuring?

A dosimeter measure the sound pressure level, measured in decibels A-weighted, dBA (usually). It can record this level and average it (usually) for every 1 minute period. The amount of information it gathers is staggering…and confusing.

  • What if we work a longer shift (more than 8 hours) will the results of the noise monitoring be the same?

Yes, the results are (usually) given as an average. So, in theory, if you measure the noise for 15 minutes and it is the same for the next 7.75 hours, it should be the same. However, if you work more than 8-hours a day OSHA actually decreases the amount of noise you can be exposed to. They have a table (G-16)  that attempts to explain it.  If you know the average level of noise (say it’s an average of 95 dBA 8-hour TWA), then you can determine the time you are allowed (answer: 4 hours).

  • How often should noise monitoring be performed?

There is not a specific rule from OSHA on how often you must monitor. However, the guideline is yearly.  Or if/when significant changes occur “which might effect the results of this testing” (I always use this statement in my reports).

  • Which individual employees should have their noise level measured?

It is best to let the industrial hygienist make this determination (there are several good reasons). If you are just starting out, they will often choose an average, or those who might have the highest noise level exposures.

  • I’m wearing hearing protection, why don’t they take that into account when they determine the average readings?

Your exposure is determined without regard to the specific type of hearing protection used. If you are wearing the wrong type of hearing protection, or if it is worn incorrectly, you could still have this exposure.


Most welders wear ear plugs. Why? Because of noise, sure, but also because of slag entering into their ear canal and harming the ear drum.

The average noise levels can vary throughout the day – depending on the project. During the day of this survey, welders were tacking and fabricating stairs and handrails. However, their typical business is large tanks. Do you think the noise levels might vary depending on what they’re making? I do.

I’d also bet that air monitoring during these events would vary. If the welder is inside a large tank performing welding for a few hours, I’d worry about more than just welding fumes. (some might be: welding gases displacing oxygen, electrical hazards, heat exposure, UV, and also the welding metal and rods).

Be safe out there!

I know, the title is wrong.  It should read:  “How to prevent hearing loss“.

Here’s the problem (IMO).  I think most people know how to prevent hearing loss- and in America we can all afford to buy ear plugs. I have also heard of hearing loss claims that are unfounded and totally unrelated to their current work activity.  Even just a one time loud event can cause permanent hearing loss.

Construction companies hand out ear plugs like candy and say, “wear them when it’s loud”. Then, these same construction workers go home buck-up a cord of wood, ride their motorcycle, shoot their gun, and then after dinner go to a rock concert.

So, to avoid a claim, here is my advice:

  1. Measure the noise (by dosimetry) at your job site- and do it annually.
  2. Start a “hearing conservation program” or, in the simplest words, have your employees’ hearing checked annually.
  3. Educate (train) your employees in hearing conservation
  4. Give them choices in hearing protection (different brands of plugs, muffs, etc.).
  5. Manage their hearing- (see below)

If you notice a loss in their hearing- do something! To manage possible hearing loss, I suggest these additional steps:

  1. Retest their hearing. On a Monday, before work.  (To avoid a possible temporary threshold shift)
  2. Have another company test their hearing. (sometimes the equipment is out of calibration)
  3. Remind your manager to enforce the employee’s use of ear plugs on the job site.
  4. Offer to give them ear plugs to take home.
  5. Have an Industrial Hygienist (IH) perform noise monitoring at the job site for the full shift (dosimetry).
  6. Retest their hearing again a month or two later.
  7. Have an audiologist review their audiogram & your noise sampling data and ask for an opinion.

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