Launched Audacity and immediately there was a 100% volume high pitched tone. Lowering/muting the system volume made no difference, the sound persisted. The only way to stop the sound was to physically pull out the speaker cable going into the audio out port on the back of my PC. When I plugged it back in again, the sound was gone.
This has only happened a couple of times now and may not be Audacity’s fault, but does anyone have any idea what might have caused this?