Question I can finally hear! (but only for a moment)

[John C. Ratliff]

I’m a long-time diver, and am also a retired industrial hygienist who in on the American Industrial Hygiene Association’s (AIHA’s) Noise Committee. We look at the detrimental effects of noise on the human ear. But what you describe is not something that will harm the ear, but rather an enhancement of hearing because of something having to do with your bubble exhaust.

I think what you are describing is that an exhaust bubble temporarily displaced your hood, opening up an area around the ear (one ear, most probably) to the open water. Water transmits sound much faster than air, and sound is omni-directional. So an opening will allow the sound direct access to your ear, rather than having to go through the neoprene of the hood (a sound barrier). Then, when you looked up, the bubble went away, the hood closed again, and the sound was again muffled.

You can test this hypothesis by opening the hood on your next dive with a finger, and see if that’s the difference. Or, by diving without a hood if the conditions are such that this is comfortable.

Anyway, best wishes,

SeaRat

 

[gmerick]

I wear a Perdix on my wrist, and an AquaLung 200c clipped on my shoulder next to my "good" ear. I've never heard either computer, but when reviewing dive video, I hear the beeps at all the right moments. I've gotten used to having both computers within my visual range and watch for screens to flash. Until some techno-geek invents underwater hearing aids, that's the best I can do.

 

[rfwoodvt]

I wear a Perdix on my wrist, and an AquaLung 200c clipped on my shoulder next to my "good" ear. I've never heard either computer, but when reviewing dive video, I hear the beeps at all the right moments. I've gotten used to having both computers within my visual range and watch for screens to flash. Until some techno-geek invents underwater hearing aids, that's the best I can do.

I run a Suunto. Same issue. Have never heard the computer. On surface I can't hear my dive mates either.

Wondering if I can/should punch a hole or three over my ear canal in the hood.

Thots anyone?

 

[crofrog]

I wear a Perdix on my wrist, and an AquaLung 200c clipped on my shoulder next to my "good" ear. I've never heard either computer, but when reviewing dive video, I hear the beeps at all the right moments. I've gotten used to having both computers within my visual range and watch for screens to flash. Until some techno-geek invents underwater hearing aids, that's the best I can do.

Perdix doesn’t have any audible alarms…

 

[Jai Bar]

I think the problem is a simple water/air boundary. Due to the difference in both speed of sound and density between air and water, most of the sound waves are reflected, hence you hear them muffled. The hood also has air trapped (neoprene) and contributes to sound reduction, it also absorbs a good deal of sound. In most cases this does not impede equalizing.

If you get rid of trapped air in the ears (lift the hood a little bit, tilt head until both ears fill with water) you will hear better, but the hood still reduces a lot of sound. You may have a narrow ear canal (I do), which makes it harder to fill with water during dive and sometimes also to drain post dive.

I frequently dive in a site with dolphins, but in winter I can hardly hear them approaching because of hood, then they surprise me by zooming in front of my face. Summer, I can hear the buggers alright from good distance, they can't sneek up on me.

As to pro ear mask, I've got one, but I found it annoyingly loud with self bubbles and breathing that I use it only after several days of intensive divings, to ease a little on the ears, avoid infection etc. and quite often I flood the ear compartments to have some quiet.

 

[Ryan Neely]

I've been playing with this, and I think you're right about it being basically a bubble of air that gets trapped in my outer ear for a moment, displacing the water.