[chuck-users] Analyse voice and choose animal

Hi, Here's what I'd like to achieve: There's a pool of samples of animals. There's a microphone. Someone talks to the microphone, the voice is analyzed and, based on a given similarity criteria, an animal is chosen. To be honest I don't know how this can be done and if it is easy or hard. Should I try using FFT to determine, say, the main frequency and decide from there? Which other criteria should I be able to compare? Any links or samples to get me started? Thanks, Nuno