Well, this is seriously weird. It is a communication device that doesn't have any electronics in it. It can be used to speak to people standing next to in a very loud place (underground, for example). I don't a way it can stop working or break, its only minus is that I wouldn't like to appear in a public place wearing such a thing on my head.
Step 1: The Main Part
the main thing you should get are two medical stethoscopes. This is were this device actually started off: I had a stethoscope and when I took it to school, I was surprised how well you can hear someone speak directly in its membrane, and how badly all the noise around (breaktime at school is as noisy as the underground). I got my stethoscopes from a local big chemist quite cheaply.
Step 2: Other Instruments and Details
Here is a photo of some of the things I used. I also used two washers, to rather stiff springs from an electronics kit, two rubber toroids (sorry, my technical English is really terrible), and two great aluminium things I fould at the bottom of my wokshop that proved to be really useful. ( I'll show them later).
Step 3: The Membrane Stands.
I think it is best to see the picture.
Step 4: Membrane Stands Mounted.
Well, this is how I did it. ( I used the spring so that the membrane stand can tilt forwards on different angles to accommodate different peoples' chins.) If I did this Instructable, I would rather think of my own way to build a membrane stand, than make this aluminium things if I didn't have them.
Step 5: Assemble It All Together.
I don't think it needs a lot of comments either. This was my process.
Step 6: Finished
This is me in my final product. I took the photo myself, so it is rather strange. ( I'm not always that ugly, maybe it is just the device that make me look weird???)
If you've read all this, please help me to make this Instructable more understandible for other people by telling me how are things called:), thank you.