2 Prong Headphones on Planes

Ive always wondered, why do airplanes have 2 prong for headphones?
I googled around and some say its because they dont want people to steal the headphones, but hey, if its 2 ports and rare outside, wouldnt that encourage ppl to actually steal them?
Some ppl say its to sell them in planes, ppl would be forced to pay for them to make extra money...
Some weird ones ive seen is that its got something to do with the pressure... no idea what pressure has to do anything with...
Anyone know the real reason?
I only ask cuz im about to fly overseas and i was looking for my adapter for my headphones. :]

I've been using regular headphones for quite some time on airplanes.

Quote from uniquename : I've been using regular headphones for quite some time on airplanes.

They are the "older" use of the 2.5mm jacks. They are two as one is for right and left audio. In the 3.5mm, they are consolidated into one prong. You can always bring a 2.5mm adapter if you're worried. The 3.5mm jack is more common across airliners but you never know if there's an older one in the fleet that isn't upgraded yet.

Quote from Albort : Some weird ones ive seen is that its got something to do with the pressure... no idea what pressure has to do anything with...

The older style actually had the speaker embedded in the armrest, and the "headphones" were just hollow rubber/plastic tubes to conduct the vibrations (in the form of air pressure variations) to your ears. This made the "headphones" so cheap that they were basically disposable (which was good, since you were supposed to stick them into your ears).

I haven't actually seen a plane with that setup in some time.

A slightly newer style uses 2 electrical jacks, each basically a mono 3.5 mm jack. To the best of my knowledge this was basically done to get you to pay them for headphones to use their in-flight entertainment system.

There's also apparently yet another setup with a 3.5 mm jack and a 2.5 mm jack for noise-canceling magic: http://eu.audio-technica.com/en/s....asp?id=55

Plain old single 3.5 mm jacks are becoming the norm now on most airlines.

Also, this site may be helpful: http://www.seatguru.com/

when I worked for an airline we would take the used headphones and were supposed to "sterilize" them and repackage.

We frequently ran out of the sponge ear thing, so we would just wipe them off with an antibacterial wipe, throw them in a new bag and seal them. Sometimes we did not have wipes, we just threw them in bags and sealed them.

Quote from skipadedodah : when I worked for an airline we would take the used headphones and were supposed to "sterilize" them and repackage. We frequently ran out of the sponge ear thing, so we would just wipe them off with an antibacterial wipe, throw them in a new bag and seal them. Sometimes we did not have wipes, we just threw them in bags and sealed them.

I bring my own.