Detection of sharp peaks in an audio signal
"Sharp peaks" in the time domain translates to high frequency content. Your simple algorithm of min and max values would be improved by first passing your data through a high pass filter - otherwise slow (low frequency) rumbles could degrade your detection methods.

To take your solution to the next level, you should use an "onset detection" algorithm. These are well studied. A recommended paper to start is:

A Tutorial on Onset Detection in Music Signals - Juan Pablo Bello et al, September 2005.