Differentiate between clapping and talking
What's typical for clapping hands is that it's a sudden short, but strong sound.
A possible way to detect it is to trigger an MMV (Monostable MultiVibrator) with the input signal if it's higher than a certain threshold, and see if this high level is still present when the MMV times out. If it isn't it was probably clapping hands. You'll have to experiment with threshold level and MMV time.