Sound: It is a kind of vibration of material molecules (such as air) that propagate in the form of waves. Vibrations with a frequency between 16 Hz and 20000 Hz are within the audible range and can form sensory impressions in the human hearing. Different people has different hearing ability. Vibrations with a frequency lower than 16 Hz are called infrasound, and those with a frequency higher than 20000 Hz are called ultrasound.
We can know from the above definition:
 Vibration between the infrasound and ultrasonic frequency range cannot cause a sensory impression of human hearing