Unable to get rid of beeping sound from 2021 MacBook Pro

My 2021 MacBook Pro (18,3) recently started making a strange beeping sound. I would like to know its source since the sound makes me somewhat concerned and is also quite irritating. I’m running macOS 12.6.3. I’ve characterised the beeping below:

• I made a short recording of the beeping.
• Attaching headphones or adjusting volume have no effect, i.e. the beeping can still be heard. (I’m not even completely sure if the speakers are the source.)
• The beeping stops sometimes even for a long time but so far has resumed later.
• The beeping starts again after reboot.
• SoundSource doesn’t list any applications that produce audio output.
• The beeping happens even in the login window but (so far) not in Safari launched by a guest user.
• I tried uninstalling the Teams audio driver and stopping Adobe’s processes but these didn’t seem to have any effect.

Any advice is appreciated.