Answer: ultrasonic

AnswerCrossword Clue
ULTRASONICTop Seattle cager?
ULTRASONICAlmost too high to hear
ULTRASONICToo high to hear
ULTRASONICToo high to catch?
ultrasonicdenoting air-waves or vibrations with frequencies higher than those audible to the human ear
ultrasonicOf or involving sound waves with a frequency above the upper limit of human hearing