The Druufs' speech organs produced sounds in the ultrasonic range.
They are also particularly sensitive to high-pitched noises and can hear and communicate in the ultrasonic range.
Charley was speaking slowly and clearly, staying well below the ultrasonic range, but even so Torrance often had trouble translating.
The ultrasonic range refers to the very high frequencies: 20,000 Hz and higher.
The seals 'talked' with each other in the ultrasonic range and it was inaudible for human ears.
Machine friction and stress waves produce distinctive sounds in the upper ultrasonic range.
This species produces vocalizations in both the sonic and ultrasonic range that are thought to be an important component of its communication behavior.
People can understand words spoken at high ultrasonic ranges once thought to be far beyond the capacity of human hearing, scientists have found.
Some animals such as dogs, bats, and rodents can hear well into the ultrasonic range.
This may lead to high-amplitude pressure oscillations, often in ultrasonic range, which may damage the motor.