Sound problems in professional audio programme after instal of paid Avast.

My audio transcription programme now stutters and squeals and stops and all sort of things. It never did this with the free version. Someone help me. This is my work.

Saying something isn’t working correctly without providing details is not helpful.

What OS/SP ?
What exact version of avast ?
Any other security (related) software installed ? (or was there)
What is the sound application ?
Does it makes a difference if you disable one of the shields ?
etc etc