Three different vibrating objects produce three types of sounds X, Y and Z. The sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X can be heard by a bat whereas the sound Y can be heard by a rhinoceros. What type of sounds are X, Y and Z?

X : Ultrasonic sound waves (Greater than 20,000Hz)

Y : Infrasonic sound waves (0-20 Hz)

Z : Audible sounds (20Hz-20,000Hz)