Decible levels in freefall? In the aircraft?

[Praetorian 1]

for free fall put it inside your jumpsuit ... how your going to read display .. is another issue

Good Judgment comes from experience...a lot of experience comes from bad
judgment.

[droidicus 0]

Radio Shack has two different meters, one is an analog the other is digital, the digital one that I have has a maximum setting, so you could shove it in your jumpsuit and read the maximum SPL once on the ground. My suspicion is that the loudest part of the whole thing is at the door of the plane, you have plane noise AND wind noise at that time. Also, if your meter came with one of the foam hats to put on it you might want to use it so that you don't get additional noise from the wind interacting with the microphone.

Please do let us know your results, it would be interesting to find out.

[Remster 30]

I'm no noise analysis expert, but readings while in freefall are not gonna mean much. These dBmeters are usually made and calibrated with zero wind amd the air pressure of the wind would fuck up readings.

In freefall, the air presssure is more or less equilibrated between our ears and mouth/nose. You cant to the same with a dB meter.

I think anyways... my courses on this were done a long time ago.

Remster

[droidicus 0]

If it were inside a jumpsuit and with that little foam wind-blocker thing I think it would be at least a good approximation. Holding it in your hand might not work well, but then again I wouldn't recommend that either.

I might be able to convince someone at my work to loan me a small calibrated mic that I can stick inside my helmet to connect to a SPL meter, but I would have to so some leg work to get that done.

[kelpdiver 2]

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I'm no noise analysis expert, but readings while in freefall are not gonna mean much. These dBmeters are usually made and calibrated with zero wind amd the air pressure of the wind would fuck up readings.

And since the question is potential hearing damage, the sensor really needs to be close to the ear as the wind/helmet interface can be quieter or louder than what you'd hear inside the suit.

There is a huge variation in noise levels for motorcycle helmets.

[crutch 0]

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Question: why dont you guys want to wear hard shell open faces on tandems?

This has been hashed over many times in other threads, so let's don't hijack this one.

Back to the subject at hand. I have worn earplugs since about my tenth jump. It is a little hard to hear in the plane, but I can still hear on the ground. Back in the day 30 minutes in the Soutern Cross, 7 or 8 times in a day would cause anyone's ears to be ringing. I use the foam ones on a string, a box of 500 is $30 dollars I think, something like that. They have a db reduction of 23 I think.

blue skies,

art

[champu 1]

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If it were inside a jumpsuit and with that little foam wind-blocker thing I think it would be at least a good approximation. Holding it in your hand might not work well, but then again I wouldn't recommend that either.

The only way to get useful information in freefall (with regards to hearing damage) would be to use a small probe tube inserted into the ear canal fed to an spl meter that you could then stick wherever.

The SPL at your ear drum might be wildly different from what you would measure at your waist. Particularly if you don't have a helmet on.