Algorithm suggestion: comparing sound clips

(Not sure if this is the right place for this question)

We are analyzing thousands of sound clips of people talking in an attempt to find patterns in the pitch, syllable rate, etc. in order to come up with a signature database to match new sound bites to emotions.

While I am familiar with some AI algorithms (Bayes, for instance) I'm curious if anyone has any ideas on the types of algorithms we could employ.

Overall concept (figure short 2-5 second .wav clips):

soundClip1 -> 'anger'
soundClip2 -> 'happy'
soundClip3 -> 'sad'
...
emotion = predict(newSoundClip)

Given a new sound clip, we would like to do something similar to Shazzam except for returning a probability that the clip represents a particular emotion.

Any suggestions would be appreciated!