Ultrasonic sound waves are waves of sound beyond the range of perception. These sound waves are used by bats and dolphins for navigation and by medical imaging and in non-destructive testing.Know More
The range of ultrasonic sound, or ultrasound, between 20 and 100 kilohertz is used by bats, dolphins and other species to navigate and communicate with others of their kind. Medical ultrasounds use a much higher frequency in the range of 1 to 20 megahertz. Medical testing utilizes the echo time and the Doppler shift of sounds reflected back for medical imaging. With this, they can use ultrasonic sound waves to determine the distance between organs or the speed at which those organs are moving such as with an echocardiogram.
Non-destructive testing uses both high- and low-frequency ultrasonic sound waves to test for fractures and flaws in building materials and to measure the thickness of those materials. Less-dense materials utilize lower sound frequencies in the range of 50 to 500 kilohertz. Non-destructive testing has used ultrasound technology to test the welding on joints as an alternative to radiology since the 1960s.
Sonar also uses ultrasonic sound waves similar to the way a bat uses them for navigation. A pulse of sound is sent in a particular direction, and when it bounces back as an echo, the time between the pulse and echo is measured to determine distance.Learn more in Optics & Waves
The key difference between infrasonic and ultrasonic waves is that infrasonic waves include sounds emitted at levels below frequencies of noise that can be heard by humans while ultrasonic waves are those that exceed 20 kilohertz, which is the upper limit of human noise perception. Ultrasonic waves are waves that have high amplitudes. These waves are also called micro sound, and exist primarily as longitudinal waves.Full Answer >
All ultrasonic waves share the common property of being mechanical waves with a frequency higher than the upper limit of the human hearing range. The only difference in physical properties between ultrasonic and sub-ultrasonic waves is that ultrasonic waves cannot be heard by humans while sub-ultrasonic waves can.Full Answer >
Sound waves occur when an object vibrates and transfers that energy into the air or another medium. When a vibrating object moves forward, it compresses the air molecules in front of it, and when it moves backward, it leaves a gap where they can expand or rarefy. The vibration produces many of these compression and rarefaction pairs, which travel away from the source of the vibration through the air.Full Answer >
How Stuff Works explains that sound travels in mechanical waves, and these waves are disturbances that cause energy to move. The energy is then transported through a medium. Disturbances occur when an object vibrates. This vibration is caused by interconnected and interactive particles.Full Answer >