High-pitched wavering noise

Using 2.x on Windows 7 on a PC, and Windows 8 on a laptop. Used the exe. installer. Same problem on both computers.
I have been using Audacity for two years with no problems, until last night. I’m getting a high-pitched wailing noise from Audacity on the PC, whether or not ION tape player is plugged in.
I installed Audacity 2.x on laptop for the first time, and I’m still getting the same noise.

Which Audacity exactly? You can get Audacity 2.1.0 from here.


When it asks you to reset Preferences, say yes.

Don’t plug in any USB or external devices. Close Audacity.

Can you play a YouTube clip and does it sound OK?