How can I create a device that indicates the direction of sound source?

[majestic]

hi Guys,
there is a science exh. in our school, i am thinking of creating a device which indicates the direction of sound source , is there any way to make it ?

 

[ranger]

Use your ear as an example. You can tell the direction of sound based on the time delay the sound takes to get from one ear to other.

You would need to design something along these lines. Any ideas where to start?