as far as i know, there are two mics like this. the parabolic mic, like David said, and there is also the shotgun mic, which is a long mic with a bunch of different lengths of tubing in it that are (and i don't know if this is the right term) resonant for a certain frequency. so you have different tubes, each one that amplifies a certain frequency, so you can have a range of like 100HZ-5KHZ (that is totally guessed, just an example)
search for more info on google.