Here's a handy class for SuperCollider. It's an audio clipping detector loosely based on Batuhan Bozkurt's StageLimiter.
To install it download and extract the zip file into your SuperCollider extensions folder. Then recompile and type...
Now as soon as you play a sound that's clipping (i.e. exceeds -1.0 or 1.0), the class will warn you.
To turn it off type...