Increased Tinnitus Through Bone Conduction?

[Meestijn]

How is it possible that although somebody protects their hearing with e.g. 30 dB NRR earplugs, they can still experience a tinnitus spike and, in unfortunate cases, the spiked tinnitus level becomes permanent?

Is this because of bone conduction, where outer and inner hair cells can still be damaged despite using hearing protection?

Or is there another mechanism at play?

 

[Dr. Ancill]

Bone conduction is an unlikely mechanism for subjective tinnitus as this is 'caused' by the auditory cortex responding to damage in the sensorineural pathways. You should avoid earplugs unless you have hyperacusis (increased sensitivity to sound). The more external sound you can be exposed to, the more likely your brain will have its attention shifted away from the tinnitus. With earplugs, you are really focussing the brain on on the main thing it can 'hear' - your tinnitus. By all means protect your hearing - stay away from loud noise and use earplugs (the molded type not the sponge type) if you cannot avoid loud noise - work, concert, party, etc..

 

[Mr Registered User]

I said much of the following on another topic somewhere, but....

I once read that loud bass of drums can vibrate through the skull and into the inner ear, triggering or aggravating tinnitus that's already there. I'm a part-time muso with intermittent tinnitus (it never totally goes away, but the loud ringing comes and goes), and I reckon this happens to me virtually every weekend.

I only do duo gigs these days (no drums of bass), but we have some loud backing tracks that really pound through my head. Of course, I wear earplugs (especially in my bad ear), and just when I think I'm gunna get through a gig without aggravation, we'll do a track with loud bass, and *bam*, there it is.

So, while I doubt that this can start/cause initial tinnitus, in my opinion, it's definitely a trigger.

 

[Riikka]

I experienced just what you are talking about Meestijn, I was at a gig with earplugs that where supposed to filter 30 dB and my tinnitus aggravated. It is now after two months a little bit better than right after the gig, but it is still not as "good" as it used to be.

During the gig I could feel the bass quite well, so I also started to wonder whether bone conduction of the bass sound could affect the ear and the tinnitus.

Another explanation would be that the noise level achieved with the ear plugs was still too much for the ears. There are official recommendations about safe exposure to certain levels of noise, for example how long should be safe to stay in 90db. But those are general recommendations and it might be that some people are more sensitive to noise than others. My guess would be that people who got tinnitus (for example due to noise damage in the ear) have more sensitive ears and should be more careful about noise levels.

 

[erik]

This has to do with shooting guns but still applies:
Hearing Loss Through Bone Conduction Elliott H. Berger Hearing Conservation/NIHL 522

If a patient wears earmuffs in combination with custom made earplugs, can you still get hearing loss through bone conduction (through the skull) when shooting a variety of guns? What is the rate of attenuation from external noise to the cochlea through bone conduction?

Answer
The limits to the attenuation for a perfectly attenuating hearing protector, that are imposed by the flanking bone-conduction pathways, vary from about 40 - 60 dB across frequency. This means that even if a hearing protector could block all of the sound entering the earcanal, that sound attenuated by 40 to 60 dB would still get though to the cochlea, and like the sound transmitted via the air-conduction pathway, this energy can cause hearing loss. However, in all but the most extreme environments, this will be sufficient protection. For all but the most susceptible ears and all but the most extreme amounts of gunfire, noise reduction that equals the attenuation imposed by the bone-conduction limits should be quite sufficient. The much larger issue is making sure that the shooter is properly wearing the single or double hearing protection devices to get the maximum protection they can provid

 

[RichL]

Bone conduction is an unlikely mechanism for subjective tinnitus as this is 'caused' by the auditory cortex responding to damage in the sensorineural pathways. You should avoid earplugs unless you have hyperacusis (increased sensitivity to sound). The more external sound you can be exposed to, the more likely your brain will have its attention shifted away from the tinnitus. With earplugs, you are really focussing the brain on on the main thing it can 'hear' - your tinnitus. By all means protect your hearing - stay away from loud noise and use earplugs (the molded type not the sponge type) if you cannot avoid loud noise - work, concert, party, etc..

You should avoid earplugs unless you have hyperacusis (increased sensitivity to sound).

Honestly and with all due respect where do you get off advising people to not wear earplugs? You have given no real reason to avoid earplug use, just your opinion without any expert documentation or scientific explanation for this?

Then you contradict yourself with this:

By all means protect your hearing - stay away from loud noise and use earplugs (the molded type not the sponge type) if you cannot avoid loud noise - work, concert, party, etc..

Once again with no explanation as to why sponge type earplugs should not be used.

I'm afraid this whole post of yours is nonsensical and you seem to have little or no evidence to back these claims up once again misinformation which is giving members false information about ear protection.

Myself, I give no credence at all to bone conduction, which at the moment, has very little evidence to back it's claim up and until their is more conclusive evidence, we should not be scare mongering with unfounded and ill informed opinions!

I have been wearing foam earplugs for 20 + years with a good 60% of that time wearing them 24/7 and my hearing is the same as when I first got tinnitus 25 years ago, I have NOT acquired any so called bone conduction hearing loss at all!

 

[Martinf]

I have been wearing foam earplugs for 20+ years with a good 60% of that time wearing them 24/7 and my hearing is the same as when I first got tinnitus 25 years ago, I have NOT acquired any so called bone conduction hearing loss at all!

This is so re-assuring. Thank you!

 

[K.A.]

Old thread woken up I guess, but something I have actually started wondering a lot about is whether the occlusion effect has been taken into account for some of these situations especially with low frequency noise.

Yes, the body and bone (conduction) have a significant attenuation, but then the occlusion effect (especially if using earplugs not fully inserted, which is quite difficult to do correctly) has a significant amplification at the lower frequencies (up to 50 dB).

What I wonder is, might there be some situations where there is a lot of low frequency noise hitting the body (like when you can actually feel the vibrations/bass) where the use of not fully inserted earplugs actually causes this noise to be amplified so much that they cause damage?

Like, that they end up reducing the noise transmitted through the middle ear by 30 dB but at the same time amplify the body conducted noises (by the occlusion effect by 40-50 dB)?

I started thinking about this after getting new shoes, which are a bit harder than the last pair I had, causing me to find the occluded noise of bare walking quite loud. Then what if I held a vibrating device, or attended a gig with heavy bass...

Just my speculation. Any input is very welcome.