[thedoc (OP)]

We find out how microphones capture sound by asking Naked Scientist Dave Ansell if he could build one from scratch, and to do that, he looked back into the history books...
Read a transcript of the interview by clicking here

or  

[RD]

... if you can think of a way of converting a vibration into electrical signals, someone’s probably trying to make a microphone using it.

https://en.wikipedia.org/wiki/Laser_microphone

[evan_au]

The capacitor microphone on the show produced recognisable voice. However, both electrodes were made of the same material, and would be deformed about the same amount by sound waves. It might be better to have one "movable" electrode, and one "fixed" electrode.

[syhprum]

May I suggest "The Children's Encyclopædia" by Arthur Mee that has instructions how to build your own telephone system from scratch

[RE.Craig]

A very simple type of carbon/graphite mic. You will need=
1. a sheet of paper.
2. a soft "B" graphite pencil.
3. a cup, vending machine type is best.
4. an elastic band.
5. Sellotape.
6. a microphone lead with a jack plug at one end and two bared wires at the other.
Method=
Draw a large heavy dot about 1" in diameter on a piece of paper then draw a thick line about .25" through the centre of the dot about 4-5" long.
Put the paper over the mouth of the cup and secure with elastic band.
Take the bare wires of the mic lead and sellotape a wire on either side of the dot on the thick line you drew.
Plug jack into amp then talk into your mic. The bigger the dot the higher the output.
 Although very simple it is a very good method for experimenting with various pick-up patterns. 


 

[Cora]

Hi Craig
I am trying to do a school science project with your microphone and cup method but it's not working. Do you need to make a hole in the cup? Thanks