Airbags and Hearing Damage

Airbags reduce the likelihood of death or serious injury in the event of an automobile accident, which is why they have been required by law in all passenger vehicles sold in Canada since 1999. Sometimes these life saving and injury preventing benefits come at the cost of less severe injury caused by the air bags themselves. Airbag injuries can include minor cuts, bruises, abrasions and burns, which are far less severe than the injuries they prevent. Airbags inflate incredibly quickly as there are sensors in the car that will detect a collision and send an electronic signal to a small ignitor device which provides enough heat to turn 130g of sodium azide into 67 litres of nitrogen gas thereby causing the bag to inflate. This whole process will inflate a car airbag in 0.05 seconds after the initial impact. Because of the sound made by the ignition and the speed at which the airbag deploys, one possible type of injury that can be caused by airbag deployment is an injury to our ears. Noise at a level of 85dB has the potential to permanently damage our hearing if we are exposed to it for a long enough period of time. As the noise gets louder, our hearing gets damaged in shorter exposure times. Airbags deploy with a bang of up to 178dB! It’s

Airbags and much louder than the loudest human voice shouting 1 inch Hearing Damage from your ear or a jet plane taking off beside you. The saving grace is that the sound is present for only a small fraction of a second. Injuries to our ears and hearing due to this high intensity noise could include eardrum rupture, tinnitus, sensorineural hearing loss (nerve damage), hyperacusis (extreme sensitivity to noise) and balance disorders. Dr. Richard Price, a U.S. based research audiologist published a study in 2007 that found that up to 17% of people involved in an airbag deployment could suffer hearing loss.

Research on the exact number of people experiencing hearing injuries after airbag deployment is difficult because of the lack of baseline testing e.g. the general population does not get their hearing tested on a periodic basis.

At Resonance, we advocate for the importance of baseline testing and periodic monitoring of one’s hearing. This is important for several reasons and one of them is that if your hearing changes suddenly, you can compare to a baseline and can quantify the extent of the change.

Terence Miranda, AuD, RAUD, RHIP Doctor of Audiology Resonance Hearing Clinic www.resonance hearingclinic.com