I have several new Tapo cameras that I've just installed in the last 2 weeks.  All with the latest firmware and connected to a 2.4ghz only IoT wifi network and are recording to local micro SD cards, not Tapo cloud.

This issue arose when looking at footage from my C110 late last night when everything in the house was completely silent.

I can hear audio 'interference' when looking at live view or any previously recorded footage.  Listen to attached video file (video blanked for privacy)

The issue also happens on my C120 and C520 cameras though they exhibit a bit more of a rhythmic buzz than the chirp but there still appears to be a pattern of interference rather than random stuff.  My battery powered TD21 doorbell camera seems less affected though I can hear faint noises on this feed as well.  However my older TC60 camera doies NOT have any interference.

It sounds like possible power interference?  I have checked the powerline frequency settings on the cameras and they are set to AUTO though changing to 50hz (for UK) makes no difference.  Turning the camera mic down from the recommended setting decreases the noticeable noise.

I have a TPLink Deco PX50 mesh network with a powerline backhaul that was the only thing I could think could be causing this issue but I've ruled this out by turning off the satellite device, thus shutting down powerline, and the noise continues.  Listening late at night with nothing else on in the house makes no difference so I cant imagine its a specific device causing the problems.  The issue happens at all times of day so the LED street light opposite my house can also be ruled out.

I can't remeber this issue with my old Kasa cameras though, which is strange.

Any suggestions are welcome.