What are sonic waves?

Hint: Sonic waves are type of sound waves of inaudible frequency range. A normal human ear can’t hear this type of sound waves. But many of the animals can hear these sounds. Frequency of these waves is above $20,000\,{\text{Hz}}$.

Complete step by step answer:
A normal human ear can hear a sound of frequency from $20\,{\text{Hz}}$ to $20,000\,{\text{Hz}}$. When the waves have a frequency above $20,000\,{\text{Hz}}$, then the sound waves are called sonic waves.
Due to this humans can’t hear or feel these waves.
Ultrasonic devices are used to detect objects and measure distances. Ultrasonic imaging or sonography is often used in medicines. Ultrasound is used to detect invisible flaws.
Sound waves exist as variations of pressure in a medium such as air, they are created by vibration of an object, which causes air surrounding it to vibrate. Sound waves can travel through air, liquid or gas but not from vacuum.

Note:
Animals that can hear ultrasounds are bats, dolphins, moths, frogs etc. but humans can’t hear. Also waves which have frequency less than $20\,{\text{Hz}}$ are called infrasonic waves, these infrasonic waves are audible to elephants, rhinoceros and hippopotamus. When we talk about waves, the first animal that comes to our mind is the dog. Can dogs hear infrasonic or ultrasonic sounds or not? So, the answer to this question is yes but only ultrasonic not infrasonic because they can hear a sound of frequency range from $40\,{\text{Hz}}$ to $60,000\,{\text{Hz}}$ .