there's quite a lot of programs that are free and up to the task. some are free to. will post some up later on.

if i were you i would use sth. like tobybears minihost

http://www.tobybear.de/p_minihost.html

and load a quality spectrum analyzer like waves paz analyzer in there.
or other vst plugins you like for that job.
or in fruity loops route the input channel(s) to an fx channel and do as above, i.e. load a spectrum analyzer.

it should work without extra plugins in wavelab and similar programs (u can load vstis there too...)