Infrasonic waves: The sound waves whose frequency is less than 20 Hertz are called infrasonic waves. Infrasonic waves are not audible to human ear. Infrasonic waves are produced by vibration of earth surface during earthquake. Some animals like whales, elephants, rhinoceros etc can detect and produce infrasonic waves.
Ultrasonic waves: The sound waves whose frequency is more than 20000 Hertz are called ultrasonic waves. These waves are not audible to human ear but animals like bats, dolphins etc produces as well as detect the ultrasonic waves. These animals produce infrasonic waves in order to catch the prey as well as identifying the obstacles ahead. The ultrasonic waves produced by these animals reaches the obstacles or prey ahead which when reflected is felt by these animals and hence can easily catch the prey.
Application of ultrasonic waves
Ultrasonic waves has very wide ranges of application all human life. Some of the major applications are listed below.
- Ultrasonic waves are used to detect and check the condition of the fetus inside the pregnant women.
- It is used to locate the kidney stones and tumors inside the human body.
- It is used to kill bacteria inside the liquid.
- The depth of the sea is determined by the help of ultrasonic waves.
- Sterilization of the metals is done with the help of ultrasonic waves.
- These waves are used to find the cracks and tears in metals.
- These waves are used in submarine and ship to ship communication.