Converting Sound Energy To Electrical Energy To Light A Light Bulb

[sciencefairfail]

Okay so i need help. This is my first year doing science fair and i'm completely confused with my project. I need to find a way to convert sound energy into light energy in order to light an LED. i've read several forums and gone to many websites but still cannot find my answer. My first idea was to constuct a lamp that is lit by sound energy, but i cannot come up with a solution. please help if you have any ideas!! :(

[Turtle]

try wiring a loudspeaker to the LED & then beating a drum (or making some other suitably loud sound) near the speaker.

[sciencefairfail]

thanks so much!