[HiFiChris]

The airbag (and active belt tensioner), while it highly improves vehicle crash safety, also brings some negative effects for those who are babying their ears and concerned about their hearing: when deployed, a very loud bang follows at the same time, caused by its bursting charge going off. This short burst of noise does usually have an SPL that is equal to a fired rifle.
This is mainly the reason why I don't like the airbag.

But anyway, the crash itself sans the noise caused by the bursting charges for the airbags and belt tensioners firing off isn't quiet either (I unfortunately don't have numbers for the SPL of the pure crash noise SPL inside the driver's cabin).

And this is where it is getting very interesting with an innovation I just stumbled across: In this year's W213 E-Class, Mercedes-Benz is for the first time offering a feature that might lower the risk for our hearing during a car accident: as soon as the car's active safety monitoring systems foresee a crash or very risky situation, an 80 dB burst of pink noise is played through the car's built-in stereo system in order to trigger the Stapedius Reflex, making our hearing less sensitive and stiffening our eardrums right at this moment.

This new safety feature is called PRE-SAFE® Sound and although it is just a small invention, it might me a big accomplishment for all of us hearing-concerned people if it can really lower the risk of damaging our hearing during an impact.

As the airbags aren't especially mentioned, I hope that the pink noise is played a little before the airbags deploy and the belt tensioner bursting charges fire off, else it is somewhat meaningless or at least not as effective/protective as it could be.

 

[RRod]

Neat, and a good bit softer than I was expecting (which is good in case the darn thing glitches). I don't suppose they can make one that goes off right before my toddler screams in my ear?

 

[Don Hills]

...  as soon as the car's active safety monitoring systems foresee a crash or very risky situation, an 80 dB burst of pink noise is played through the car's built-in stereo system in order to trigger the Stapedius Reflex, making our hearing less sensitive and stiffening our eardrums right at this moment. ...

 
I foresee a problem - a sudden distracting burst of noise right when I'm trying to deal with a "very risky' situation" may well make the situation worse..

 

[icebear]

I guess everybody has his own priorities in case of a crash. Noise seems to be the least of problems.
Making sure the seat belts work properly and the airbag gets deployed correctly without propelling any metal shards into the passengers face, neck, body should be top priority. Hopefully not a Takata manufactured airbag.

I have never heard that anyone complained about hearing damage after he/she survived a crash with airbag deployment. Usually getting rid of all kinds of problems related to the head being accelerated too fast, i.e. neck and shoulder related syndrome will be much more important than any temporary hearing loss. Sound like MB's marekting found a solution to a not really relevant problem

 

 

[HiFiChris]

Don Hills

As it seems the noise is played milliseconds before the impact, so I wouldn't worry about it. But you're right, all of those assistance systems might also distract the driver for a second. I always get scared like sh... even when the car beeps because of the outer temperature going down or when the fuel indicator wants to tell me that I need to refuel soon. Anyway, I'm starting to drift a little off-topic as it seems...


icebear

I've read of tinnitus, hearing loss and ruptured ear drums after airbag deployment quite some times. Not much surprising though given the SPL caused by the bursting load going off.
If PRE-SAFE Sound can reduce the risk of permanent hearing damage caused by the noise of a crash, it is a good invention.

I'm kind of glad in retrospective that the only more serious accident I've been involved in happened almost two decades ago in a car that didn't have any airbags (got rear-ended at a red light in standstill at probably less than 30 mph/50 kmph). Some neck injuries were the only aftermath as far as I remember.
Fortunately a few years later when I got into a situation where the systems could have detected a hard impact, nothing happened and the airbags didn't deploy (I lost control in a corner at ~ 80 km/h when I was distracted by the passenger next to me and the car went straight on, jumped over a narrow dome, got a little air time for a few split seconds and then landed in a (soft) field. Fortunately due to the field, the impact was rather soft so the systems didn't detect an abrupt stop which would have been the case if there was no field but a car park or road. Still the car got quite damaged and my passenger suffered neck problems, but I was quite glad the airbags didn't deploy).


Anyway, it is still interesting to see that hearing safety during an accident is being looked after by a car manufacturer.