induction stovetops create extremely loud high pitched noises, some get up to 100+ decibels. You can't "hear" it but at higher heat levels you can definitely "feel" it in your ears.
What cars produce ultrasound? I thought radar is used.
Most cars have ultrasonic sensors for parking and radar for longer range detection, such as cruise control.
Every single car from every manufacturer that has PDC sensors in the bumper, which are typically visible as 4 circular sensors on the surface of the bumper.