The room also has video cameras and a grid of beacons on the ceiling that
emit ultrasound pulses denoting their location.
Longer - lasting underwater pings Flight recorders carry an underwater location device that
emits an ultrasound pulse once a second for 30 days after it is submerged.
Not exact matches
The SonicGuard Ultrasonic Repellent from Gen7Pets is an ultrasonic tick and flea protection device that
emits a series of
ultrasound pulses that are harmless and imperceptible to humans and animals but repel ticks and fleas.