Update this question was previously titled as \"Give me the name of a simple algorithm for signal(sound) pattern detection\"
You may be interested in a the MA Toolbox, a Matlab implementation of similarity measure(s).
I personally found this paper, General sound classification and similarity in MPEG-7, interesting. However, it might be behind a paywall (I don't know) and it might not be that useful in practice.
The GPL-ed framework Marsyas has a tool for machine learning classification, called kea. My guess is that this probably does not do what you want or is too much effort to hook up to.
My only idea otherwise is to take Fourier transforms, effectively transforming your sounds into grayscale images. Then use one of the many image similarity algorithms.