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Offline moccacake

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pressure inside airplanes
« on: 22/04/2007 20:10:30 »
how come we lose hearing in our ears gradually when an airplane climbs higher? while this is happening, when we swallow saliva to get our hearing back, what causes our hearing to return to normal level?


 

Offline neilep

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pressure inside airplanes
« Reply #1 on: 22/04/2007 20:35:33 »
Hi Moccacake.........it's always good to see you.

Swallowing must cause a pressure variance inside your ear canals.....the very act of swallowing moves air about in your ear/nasal/throat area as they are all connected .

Lets hope a passing ENT specialist answers.........
 

Offline daveshorts

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pressure inside airplanes
« Reply #2 on: 25/04/2007 10:18:00 »
Your ear is essentially a cavity with a drumskin - eardrum across the front. Minute air pressure changes in sound make the ear drum vibrate which is then detected through various bones as sound.

 When the pressure changes quickly this means that there is a big pressure difference between the outside world, this will either blow up or suck in the ear drum, either way the ear drum is stretched. If you have ever felt an inflated balloon it gets a lot stiffer, the ear drum does the same, so the same size of sound vibration will make the ear drum move less far, and therefore sound  quieter.

When you swallow, it opens the eustatian tube balancing the pressures again allowing you to hear normally again.

 

Offline ukmicky

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pressure inside airplanes
« Reply #3 on: 25/04/2007 14:12:24 »
Cheers Dave ,Ive always wondered about the swallowing thing . This maybe beyond you and more in Chris's territory but why does swallowing not work with some people like my daughter for instance.

 

 

Offline Batroost

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pressure inside airplanes
« Reply #4 on: 25/04/2007 17:33:27 »
Quote
how come we lose hearing in our ears gradually when an airplane climbs higher?

Although passenger aircraft are pressurised, they are not maintained at an internal pressure equivalent to that on the ground. It's not a big difference - perhaps, for a typical aircraft, 1.5psi/10kPa at 35,000 ft but this is why there is a gradual impbalance in pressure built up across the ear.

I believe I heard somewhere that children's eustachian tubes/inner ears were more prone to being blocked/congested (perhaps because they are that much smaller?) so there is a greater chance that a child swallowing would not clear the pressure difference. Put another way, try flying with a head-cold - can be uncomfortable!
 

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pressure inside airplanes
« Reply #4 on: 25/04/2007 17:33:27 »

 

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