How to remove / cancel 17000hz noise? Help!

[ChronoCross]

Hi everyone!

Just bought a car (Toyota Fortuner 2007) and for some reason the airbag module emits a 17.000 hz high frequency sound which is driving me crazy .

Not to confuse with the actual airbags, the module its only a box in the inside of the vehicle that controls the electric signals .

Of course, no one else that I know can hear it (as its quite difficult to hear that frequency for non audiophiles like us haha) so I had to download an app on my phone that actually shows in graphics the frequency the module is emiting to prove i am not crazy. Toyota in my country says module is working perfectly, and nothing they can do about this 17000 hz noise, only thing they can do is replace the module with a new one that seems that emits an 18000 hz noise.

Do you know how could i remove or at least diminish this noise? I was reading polyester or polyurethane help against high frequencies. So maybe i could cover this airbag module with this materials.

Any tip or trick that you guys can give me i would appreaciate a lot, as i would actually end up selling the car if i cannot solve this.

thank you.

 

[Blumlein 88]

What size is the module and how much space is around it? How is it mounted? Are pictures of it possible?

Now it is possible if it is in a metal casing some fairly thin material might soak it up and kill the resonance at that frequency. A thin sorbothane sheet or something similar. But this is a guess only. Sorbothane sheets can be purchased relatively inexpensively (at Amazon for instance). Sorbothane claims to absorb 50% of the energy over 10 hz to 30,000 hz. Of course unless that is enough to dampen a resonance (if it is a resonance) it might not kill the sound level more than a few db.

If it is in some sort of bracket a sorbothane gasket between it and the bracket along with maybe a thin sheet glued to the surface of the module might do the trick.

OH and do be careful messing with any of this especially the wiring as you don't want to accidentally set off the airbag.

 

[JSmith]

only thing they can do is replace the module with a new one that seems that emits an 18000 hz noise.

That would be better wouldn't it, or can you hear 18kHz as well?

If you played a tone of the same frequency and intensity but out of phase, the two would cancel each other out, however this probably isn't practical. Certainly looking @Blumlein 88's suggestion would be worth a look if you don't want it replaced by the 18kHz option.


JSmith

 

[LTig]

Take the new one any way. If you still hear the 18 kHz resonance go for @Blumlein 88's advice.

 

[Holmz]

That would be better wouldn't it, or can you hear 18kHz as well?

If you played a tone of the same frequency and intensity but out of phase, the two would cancel each other out, however this probably isn't practical. Certainly looking @Blumlein 88's suggestion would be worth a look if you don't want it replaced by the 18kHz option.


JSmith

Not really.
Usually one tries the attenuate passively like @Blumlein 88 suggested.
One could generate a tone, if it is was precisely locked to the 17kHz and the phase adjusted to be 180 degrees out.

But if it is not colocated then we get grating lobes that change - probably ear to ear. It is about a 1.25 to 1.33mm wavelength (17 kHz) so it get difficult in a lab, and in a car… forget it.

Just wrap it is some absorber like @Blumlein 88 suggested and call it a day.

However a tuned absorber at 17kHz would be an elegant passive solution and should be pretty effective.
(i.e. A spring and a mass tuned to 17 kHz)

 

[FrantzM]

Hi

Welcome , I don't have a solution, but do know that... most of us hate you for being able to hear 17 KHz...

Ducking, I am willing to bet that 80% of us on this forum can't go past 15 KHz.

Peace and again Welcome.

 

[tomtoo]

Would be a intersting test for a noise cancelling headphone.

 

[BDWoody]

Any tip or trick that you guys can give me i would appreaciate a lot, as i would actually end up selling the car if i cannot solve this.

That sounds damned annoying...

At that level, it probably won't be long before you can't hear it anyway. Let an older relative drive it in the mean time and you can go give it a test drive every few months.

 

[ChronoCross]

Thanks everyone.

What size is the module and how much space is around it? How is it mounted? Are pictures of it possible?

Now it is possible if it is in a metal casing some fairly thin material might soak it up and kill the resonance at that frequency. A thin sorbothane sheet or something similar. But this is a guess only. Sorbothane sheets can be purchased relatively inexpensively (at Amazon for instance). Sorbothane claims to absorb 50% of the energy over 10 hz to 30,000 hz. Of course unless that is enough to dampen a resonance (if it is a resonance) it might not kill the sound level more than a few db.

If it is in some sort of bracket a sorbothane gasket between it and the bracket along with maybe a thin sheet glued to the surface of the module might do the trick.

OH and do be careful messing with any of this especially the wiring as you don't want to accidentally set off the airbag.

I see Sorbothane comes in different stiffness (duro, 70, 50, 40 or 30) being more expensive the lower it gets. Which one will help isolate the sound better?

 

[Blumlein 88]

Thanks everyone.


I see Sorbothane comes in different stiffness (duro, 70, 50, 40 or 30) being more expensive the lower it gets. Which one will help isolate the sound better?

I'd go with the 70 for durability in your case.

 

[tuga]

Hi everyone!

Just bought a car (Toyota Fortuner 2007) and for some reason the airbag module emits a 17.000 hz high frequency sound which is driving me crazy .

Not to confuse with the actual airbags, the module its only a box in the inside of the vehicle that controls the electric signals .

Of course, no one else that I know can hear it (as its quite difficult to hear that frequency for non audiophiles like us haha) so I had to download an app on my phone that actually shows in graphics the frequency the module is emiting to prove i am not crazy. Toyota in my country says module is working perfectly, and nothing they can do about this 17000 hz noise, only thing they can do is replace the module with a new one that seems that emits an 18000 hz noise.

Do you know how could i remove or at least diminish this noise? I was reading polyester or polyurethane help against high frequencies. So maybe i could cover this airbag module with this materials.

Any tip or trick that you guys can give me i would appreaciate a lot, as i would actually end up selling the car if i cannot solve this.

thank you.

I have the same problem with my mesh Wi-Fi boxes…

If it is the airbag I would not touch it before consulting the manufacturer; don’t play with safety

 

[Balle Clorin]

Hi

Welcome , I don't have a solution, but do know that... most of us hate you for being able to hear 17 KHz...

Ducking, I am willing to bet that 80% of us on this forum can't go past 15 KHz.

Peace and again Welcome.

10k here

 

[dan3952]

10k here

12.8 kHz for me. Normal age related. You can make test tones in REW.
The audiologist says they don't test above 10k.

 

[JSmith]

You can make test tones in REW.

Extended High Frequency Online Hearing Test | 8-22 kHz

A frequency sweep from 22 kHz down to 8 kHz.

www.audiocheck.net

JSmith

 

[Balle Clorin]

12.8 kHz for me. Normal age related. You can make test tones in REW.
The audiologist says they don't test above 10k.

8k is the highest tested normally

 

[Offler]

Hi everyone!

Just bought a car (Toyota Fortuner 2007) and for some reason the airbag module emits a 17.000 hz high frequency sound which is driving me crazy .

The car does not have a feature against rodents, or small animals? That kind of sound is usually used to repel those.