You're thinking ultrasonic TV remotes from a different millennium, long ago swept away in the sands of time. Dogs aren't bothered by the pitch, but by the loud

You're thinking ultrasonic TV remotes from a different millennium, long ago swept away in the sands of time. Dogs aren't bothered by the pitch, but by the loudness. Ultrasonic remotes were amazingly LOUD. Loud enough for some humans to perceive.