Subject: Sound-Level Meter in Science Fair Project

Dear Scientist (?),

     I'm trying to test out the effectiveness of different kinds of ear plugs 
against different kinds of sounds for my school science fair project.  I was 
planning on using a sound-level meter inside either a wooden box or a manniquen 
head, and putting the ear plugs on both sides of the head, and using the meter 
to test out the sound inside the head.  Only problem being that sound-level 
meters go for about $650. Do you know of any way i could either get access to a 
sound-level meter or something that i could use instead of a sound level meter?  
I'd appreciate any help you could offer.  

Sincerely,
Brian McWilliams

Re: Sound-Level Meter in Science Fair Project