Hello tomasc, I have resolved the problem. As I said before, Screen Recorder 3 works fine with the webcam mic and the webcam video is not required with the program but as a test I selected the webcam video in the settings and made a short clip. The result was the same sound interference as that when using Youcam 8. So I deduced it was using the webcam video in conjunction with the webcam audio that caused the interference. I then made another Screen Recorder 3 clip selecting the webcam video but used an external mic with the result there was no sound interference. Finally, I made a Youcam 8 video clip with the external mic which resulted in clear sound.