Sound set up for Microsoft LifeCam HD-3000

A already have a camera of this type which is working sweetly on an old Mac Mini. I have a second Mac Mini in another room and decided to buy a second camera so that I did not need to keep moving the camera between computers. Although this is a Microsoft product it is advertised as being compatible with a Mac and this has been my experience previously,

I plugged in the new camera and the image is perfect. However the sound is not usable since there is a constant loud tone pitched around 350Hz.

Can anyone advise of a solution. I have already (1) tried the new camera on both computers - it is the same on both; (2) sent the camera back for replacement thinking it may have a fault but the replacement does the same; (3) tried connecting it to different USB ports, switching off other electrical equipment etc with no effect.

I am using a late 2014 Mac mini on macOS Catalina version 10.15.6.

Any help or advice appreciated. I think I may be about to buy a separate microphone and use the camera for video only.