Airbags Linked to Hearing Loss

Despite airbags’ proven ability to save lives in serious crashes, the explosive propellant used to inflate the safety devices have the potential to inflict serious hearing loss in humans, an auditory researcher says.

The findings come from G. Richard Price, an auditory physiologist and consultant to Charleston, MD-based Auditory Hazard Analysis, at the recent National Hearing Conservation Assn.’s annual conference in Savannah, GA.

Using an auditory assessment algorithm that analyzes the ear’s structure for sounds greater than 130 dB, Price tells the conference that 17% of occupants exposed to airbag deployments will suffer permanent hearing loss.

Price says the algorithm accurately predicts hearing loss in 95% of cases in which human ears have been exposed to noise levels that loud.

Surprisingly, hearing loss is exacerbated when vehicle windows are down. Rolled up windows actually are less dangerous because they produce higher air pressure in the interior of the vehicle.

This higher pressure stiffens the stapes, a small bone outside the inner ear, and reduces the transmission of energy to the inner ear where hearing damage occurs. When vehicle interiors are completely sealed, raising pressures even higher, hearing damage is reduced further, Price says.

However, only North American vehicles, which usually have larger, more powerful airbags, were evaluated for the analysis. Cars sold in other markets may have smaller airbags and are likely to be less harmful.