I used to hear the remote from TVs especially old Philips ones and LG's with the single chip on them. That was until I hit 44... after that is hit or miss or just imagining.

But weren't old remotes all IR?

Some very old remotes used what effectively amounted to high frequency tuning forks. Example: https://www.theverge.com/23810061/zenith-space-command-remot...

No, not all were IR.

But all of them made by "LG" and featuring a single-chip design are either IR or RF.

Those will still have a ceramic resonator in them, as they’re cheaper than a quartz crystal. Hard to imagine them being audible, but not impossible.

In our region, some people have devices to repel moles or marten using "Sounds that are inaudible for humans". I have yet to come near to one of these devices that I can't hear. And it's not only me, my wife can also hear them, as well as my daughter. I also know some people who can't hear anything from these devices, but it feels like the statistics about what people can hear and what not are not that up to date.

Personally I can't hear much above 15.5 kHz and I can hear these devices, so they're not even particularly high-pitched.

Agreed. My mother thinks I'm lying. I will admit I feel a little bit special that I can hear her motion activated cat-poop repeller thing.

I visited her recently and wasn't sure if I had finally aged out of my sensitive ears (34 now) or if her batteries needed to be replaced.

FWIW I wonder if people do not experience physical pain from certain sounds, because people seem to be totally fine with sirens but it feels like I'm having a spike pushed into the side of my head.

When I was a teenager, the applause from the end of year school talent show caused me physical pain — enough that the teachers noticed and got me out of the hall.

This no longer seems to be the case, as I'm living right by a major junction and get random full volume sirens at least six times in the average day. I hate them, but they don't hurt.