Ways to filter out certain frequencies of a mic?

I ripped a little mic and it's amplifier out of one of those kiddie spy listening devices and fitted it with a new higher tech mic, but when i use it outside i get mostly sound from wind and stuff, not conversations. same with the inside too, everything but human voices are really really loud. what could i use to filter out frequencies that aren't in the human voice range? capacitor? inductor? what can i do for that? it's a really good little amplifier and has great quality, but i want to isolate the frequency range for human conversation.