Ugh, this reminds me of a neighbor of a family member. They have a backyard, and sometimes, it is pleasurable to sit, grill, bbq, etc. in a backyard, particularly in the summer months. You know, normal suburban stuff.

The neighbor has some sort of device that emits extremely loud, extremely high-pitched (but not ultrasonic; or at least, not exclusively ultrasonic) noise. The family member thinks its some sort of anti-rodent thing. Whatever that means in suburbia, as there are, of course, nigh-endless squirrels, rabbits, birds, etc. all over the place. The yards are all fenced, so probably no deer at least in the back yards.

But it is absolutely annoying to just get what amounts to a DoS attack on your ears when you're trying to have a pleasant conversation with someone in the sun.

Of course, the elders in the family hear nothing, and the pitch is truly that high, that yeah, older people might not still have hearing in that range. "Unfortunately" for me, I still have ears.