The form of sound energy. It gives man a sense of hearing. Sound is produced when objects vibrate. The study of sound is called acoustics. The minimum time the human ear takes to hear a sound is 0.1 seconds. This is called hearing stability.
Humans Audible Range
Humans can only hear sounds with a frequency between 20Hz and 20,000Hz This is called Sravya Avadhi.
Infrasonics
Sounds with a frequency of fewer than 20 Hz are called resonances. Echoes are caused by earthquakes and human heartbeats. Certain types of animals such as elephants, rhinoceroses, and whales can produce and hear echoes.
Some say that birds of prey, who sensed the arrival of the Indian Ocean tsunami in 2004, fled the coast screaming in terror. About 60 radio-detection stations have been set up on the globe to detect any country’s secret nuclear bomb tests.
Ultrasonics
Sounds with a frequency greater than 20,000 Hz are called hypertonic. Echoes are produced based on the electrical output of the physio. Birds especially bats, cats, and dolphins can hear as well as produce echoes. A bat detects its food and obstacles in its path based on the echoic nature of its echoes. This detection is called echolocation or biosonar. Bats can hear frequencies up to 120KHz, dogs 45KHz, and cats 64KHz.
Acoustics Applications
Mosquitoes and rats can be driven away using ultrasonic waves. Sound Navigation and Ranging or SONAR technique can be used to detect ocean shallows, sunken ships in the sea bed, and deep water bodies with the help of echoes. Ultrasounds are used in sonography scanning to monitor the growth of the baby in the mother’s womb.
3D ultrasound scanning can assess the internal structure and function of the human body without any radiation side effects at a low cost. Illness problems like joint pains, muscle stiffness, etc. can be reduced with ultrasound. Curved thin tubes, jewelry, glasses, and equipment used in operation theaters are cleaned with the help of ultrasound. Ultrasound is used to break up kidney stones into smaller pieces.