How Loud Is the Sound of Truck Air Brakes Releasing That Whooshing Noise When They Are Stationery?

[Rust]

You know, that loud whoosning sound they make when the air or hydraulic brakes release when trucks are waiting in traffic.

Today a truck made that sound near me, and it felt extremely loud!

I wonder if anyone else has had experienced this?

Thanks,

R

 

[Julien87]

I experienced this a few weeks ago. I was really startled when it happened but I think it's mainly because this sound surprised me. I don't think it's as loud as a honk and I don't think it can damage the ear.

 

[Ecip]

Hey there. (ex) Truck driver here.
It's loud but not too loud.. 90dB or so, I'd say, at its peak. Just a guess though, never measured it.

The brakes aren't releasing, quite the opposite actually. Brake pods have very strong springs inside of them that keep the brakes on/locked. When air pressure is introduced, it forces the spring to compress and release the brakes. When the parking brake is pulled, it purges the air to atmosphere, and the springs force the brake shoes onto the drums. This is a safety feature; should the tractor lose all air in an air leak, perhaps, then the brakes automatically apply.

 

[Coyotesheaven]

I've had this happen when I was standing right next to a bus once; set off a terrible migraine and a roaring noise in my ear back in December, along with hearing loss. Not sure if a one time exposure is particular will cause permanent damage outside of exceptional cases like mine.

I would say though that you are definitely looking at a noise over 90 db, but most likely no greater than 110 db. You should definitely wear earplugs anywhere near loud trucks and/or buses. Those noises are dangerous, but most likely only over a somewhat longer time frame.

 

[Rust]

Thanks for your responses @Julien87 @Ecip @Coyotesheaven !

That's interesting to hear that you are an ex truck driver, Ecip! Thanks for the info on the brakes too

Luckily, it didn't cause any long term damage. Though I plug my ears whenever I want past a truck in case it does it now.

Thanks all,
R

 

[Mark McClelland]

Oh, that's loud. And high pitched. Gets me all the time. As I said to someone a few minutes ago, life is loud. But this really can be a bit of an issue, especially with the high pitch. A daily risk unfortunately unless we want to wear earplugs all the time.

 

[MountainCreek]

When my grandmother was young, there was only one car in the village, the post car. There were horses, cows, pigs. And one car.

 

[MSF]

I just experienced this from a double decker bus--it sounded exceptionally loud, even louder than the usual public transport busses or trucks. If I had to guess it was at least 110 dB (though I know we aren't good at gauging this! but I measure as many sounds as I can with my NIOSH noise app). I have H as well as T and it triggered both of them pretty much immediately (as well as the usual shock/frustration of being subjected to that kind of sudden/loud noise). It feels worse than something like a car horn because its white noise and so include a wide range of frequencies, including high ones. For that reason does probably have the potential to cause damage were you to hear it for long enough.

 

[Alue]

It's been a while since I've been on here. I've been doing pretty well aside from the occasional loud noise and minor spike, but I just had this happen to me again. Large tanker truck that was trying to run into my parked car at the gas station released the brakes right next to me. Instant spike.

I'm sure it will be fine, but air pressure noises are especially bothering to me as it was a high pressure air tank that caused my tinnitus and hyperacusis in the first place.

 

[Alue]

Well my tinnitus is decisively louder. Here's hoping it clams back down to baseline...

This comes at a terrible time for me too. I'm regretting going to that gas station this week and not going back inside and inserting earplugs when I saw the tanker truck trying to inch past my car.

When it happened it knew it was bad, it was louder and longer than any other air brakes I've heard on buses and whatnot.