Occasionally when I record a new vocal track, the sound will be extremely “choppy” if there is a track already in existence. Up until now I have solved the issue by re-installing Audacity but this has so far proven to have been only a temporary fix.
If your computer uses Windows, try both the “MME” and the “Direct Sound” settings in the (“host”) device toolbar to see if one gives better results than the other.
I use it to record narratives for audio books, and I produce a daily syndicated radio show. I was trained with ProTools and Audacity runs circles around it in some respects.