Ultrasound cannot be heard by humans as the human ear does not pick up frequencies above 20 kHz. Some animals, including dogs, dolphins and some insects can hear ultrasound. Bats have the best hearing capabilities as they not only hear ultrasound but they also generate it and can determine their location from the echoes. Ultrasonics is used in a wide variety of technical and medical applications. Echo Sounding The echo depth sounder is a device that uses the reflection of sound or ultrasonics to determine the water depth. The depth sounder determines the depth.
