Question

What is the range of frequencies associated with
(a) infrasound?
(b) ultrasound?

Answer 1

We start by defining the terms ultrasound and infrasound. The definition of ultrasound and infrasound might be based on their frequencies or time periods. This helps us to identify the frequencies associated with them and answer the question right away.

Complete step-by-step answer:
We define infrasound and ultrasound as follows,
(a) Infrasound: Infrasound is generally low frequency sound that is below the limit of human hearing or audibility. The study of infrasound is called infrasonic. This type of sound is reported to have a negative impact on human life by causing imbalance, vertigo, nausea, bowel spasm etc. Examples of infrasound include the communication of whales, elephants and giraffes over long distances and volcanoes, earthquakes and ocean waves generate infrasound waves.
(b) Ultrasound: Ultrasound is generally high frequency sound that is above the limit of human hearing or audibility. Ultrasound is a crucial part of human life as it is used in many fields in the life of a human being starting from the image of the fetus (ultrasound scan) to evaluating the blood flow.
The range of frequencies associated with infrasound waves ranges from $0.1H - 20Hz$ and that of ultrasound waves ranges from $15kHz - 200kHz$ .

Note: The range of human audibility or hearing is $20 - 20,000Hz$ . Ultrasound is the kind of sound wave that is above the limit of human hearing and infrasound is the kind of sound wave that is below the limit of human hearing. This helps us to identify the frequency range and properly define these types of sound waves.