Peeves ? Compressed air blasts cause hearing damage

[Nikki McAllen]

Thought this topic justified a new thread. It's a barely mentioned yet extremely important aspect of diver health.

In some schools there seems a 'culture' of teaching students to 'whistle' the regulator dust caps dry. In an experienced hand with decent valve control this can be done reasonably quietly, even though there is absolutely no longer any reason to do so. Simply blowing forcefully into the cap is enough to drive the water out, you can even feel it spray your lips. Better yet, use a filled style cap. Best yet, use an Apeks style Ball cap and you don't have to do anything.

I've asked numerous highly trained tech repair people if this is necessary and every single one said it's not. In fact, you can do this a hundred times and negate it all with one forgetful moment that you didn't remember to purge the tank valve before assembling your regulator. Even that's not so bad anymore with the new gear, according to them.

The noise coming out from a scuba tank is by all definitions an EXPLOSION headed for your face. It's waaaay past any Decibel meters range I've been able to find and the frequency is up there like a dog-whistle. This is extremely damaging to the ears and over time WILL cause loss of hearing. Even the purging second stages can be terribly loud.

There is a simple solution: Train your students of this risk. Teach them to cover the tank valve during the purge and face that reflected noise out to sea where most of it will remain. Tell them that purging a regulator facing their buddy is like throwing sand in their face. Let them know that good regulator care begins with the assembly sequence, not the disassembly.

Diving is hard enough on the ears. Add boat noise and hearing loss becomes a very real danger to the diving public. People who add air blasts to this already noisy environment will be reading the text on their television when they are fifty I guarantee it. I know this because I am, and it stinks.

Any dive instructor who practices or teaches damaging practices like drying their sunglasses / dust caps with prolonged air blasts should be schooled. Nobody has the right to damage anyone else's ears just because they happen to be on the same boat.

In my opinion it's an aggressive act not much different than kicking someone in the shins to knock the mud off their boots !

 

[spectrum]

Now I feel like dirt.

 

[smurf doc]

??? I'm confused. When I dove with Don Foster's a couple of weeks ago, one of the guides blew dry the cap and detached the tank from me. It was no where near deafeningly loud. I'm exposed to louder noises on a daily basis in the operating room (between people talking loudly and beeping equipment) than that.

 

[Nikki McAllen]

Don't ! Just grow and become even more professional than you already are. Ignorance and Stupidity are completely different things. You are no longer ignorant ! Good thing !

Anyone who persists doing dangerous things ? They get the other definition.

 

[Nikki McAllen]

??? I'm confused. When I dove with Don Foster's a couple of weeks ago, one of the guides blew dry the cap and detached the tank from me. It was no where near deafeningly loud.


Like I said, it can be done with good valve control, the guides have that. Students don't, many experienced divers are unaware of the risk.

My impulse to write this comes from an injury I suffered two months ago. While squeezing past folks on a crowded boat a student lost control of their valve and hit me in the left ear enough to blow my hair to the right so much it was like sitting on a motorcycle sideways.

Couldn't hear for two days in that ear, off the dive roster two weeks. Took those weeks for things to really get back to normal. I think it nearly broke my eardrum. I've been around gunfire close, this was worse. Someone with ordinance experience might have the name for the force wave that gets generated by explosions, I think the physics are probably the same.

You seem to have medical experience, and while loud I doubt your workplace is as loud as gunfire. Please concur that 150 decibel noise is unquestionably dangerous before somebody starts the flaming session. 50-200 bar air blasts are clearly in that range.

 

[stcroix]

It is startling, but it's diving. I sometimes like to cup the air with my hands to modulate the sound in order to annoy a family member or hungover divemaster.

 

[Nikki McAllen]

It is startling, but it's diving.

So is subcutaneous emphysema -- very startling indeed ! All should be treated as health risks, all should be avoided.

Nobody would discharge a weapon a meter from someone's head just to 'shake up' a hungover hunting partner.

Or at least nobody I would go diving....er I mean hunting.... with.

Deafness is not something to joke about ! What if this made someone progressively more blind ?

 

[g1138]

I think it depends on the valve. Here at my school we mainly use yoke tanks which sound loud, but not as loud as a gun shot (I've had experience in open and indoor ranges) However on the other hand we have a few tanks with Yolk-Din screw in adapters. Those things whistle out even when cracked a tiny bit. Quite loud and annoying.

I will say however that the combined might of noise and air pressure from a valve is quite hazardous. I'm always careful to point the valve away from anyone within several parking spaces in my vicinity. I haven't had an opportunity in which my area was too crowded to not do this, but if it was I'd be completely willing to use my hand or a towel to dry my dust cap.
Maybe I'll try shaking it for a change.

 

[Nikki McAllen]

I haven't had an opportunity in which my area was too crowded to not do this, but if it was I'd be completely willing to use my hand or a towel to dry my dust cap.
Maybe I'll try shaking it for a change.

I think cone-caps should be replaced by ball-caps (like the Apeks) universally. Maybe costs $1.50 at your dive shop. They work better and are foolproof.

I agree about the 'loudness' of guns, I'm from Alaska and we know guns !

Guns go Boom, but tank valves go 'Ssssshhhhhsh' at a much higher frequency and for maybe 20 times longer duration.

The frequency of a noise determines much of the damage. Boom noises and low frequency noises cause the long, flexible hairs to move in the inner ear. Since they are long they tend not to break as much.

In contrast High Frequency noises are picked up my the very short hairs of the inner ear. These are much more brittle and break easily. If you are unfortunate these hairs will fall like trees and lean against other trees and cause your ears to ring for life -- Tinnitus.

I have already encountered many dive instructors in their thirties experiencing Tinnitus. If someone dives, and their ears ring in a quite locatin, they should very carefully assess their exposures. Tinnitus is worse than going deaf. Far worse to the point of being maddening in some cases.

Compressed Air Ear Damage is a very important issue in Diving

 

[MXGratefulDiver]

There are other alternatives.

- use a towel ... it works just fine for absorbing water
- don't take your dust caps diving ... that way they won't get wet
- switch to DIN ... and skip all this nonsense

All that air blasting is a peeve of mine as well, but for a different reason. Where I regularly dive, many of the dive sites are in residential neighborhoods. Blasting air to dry your dust cap ... particularly after a night dive ... gives residents a reason to complain to their city councils about neighborhood nuisances. Divers need to be more considerate of others.

The "air blast" is one of those things that's just completely unnecessary ...

... Bob (Grateful Diver)