After spending so much time discussing why we need to set performance goals of 0.25 to 0.5% my next area of concern may seem strange. I think those of us in the hearing loss prevention business often focus too much on STS rates. We seem to have a kind of bias that concludes that as long as we have low STS rates our Hearing Conservation programs are doing okay.

I will attempt to upset that area of comfort by means of this graph. It is an idealized audiogram with the axis on the left showing hearing thresholds and along the bottom the primary frequencies for audiometric testing. The top graph shows an audiogram of a “normal young worker.” The second line coming down shows an audiogram that would be for the standard 60 year old male with presbycusis. I show a yellow dashed line at the AAO 25 dB fence. Now, what I would like to point out is that even if we have low STS rates in our HCP, the very first STS that occurs for a worker combined with the normal aging process as incorporated in the presbycusis curves puts us pretty close to material impairment.

I believe we are operating under a false set of premises where our benchmarks for success may be so lenient that what we accept as success leaves many of the workers we are trying to protect walking out of the plant at the age 65 with material impairment.

I also think this is something that may have hidden costs to the employer, the impaired worker, and society at large. We need to begin to learn how to quantify these costs and how to express them in ways that can get the attention of those whose support we need to change the current situation.