Analyzing the frequency will be the more difficult part. Not only do you require sufficient sampling speed but also a lot of hefty math functions. The 8 bit AVR chips may not be the best choice for that kind of application. There are micro-controller chips from TI and PIC that have special purpose DSP hardware on chip and are a better match for this kind of stuff.
Not saying it can't be done on a Arduino, but I'm sure it won't be a walk in the park getting the code to work. 
Lefty