Done By:12.05

Rashid Hamdan Ali Zayed Aqeel Al-Zarouni

Humaid Khamess Al-Mazmi Abdulrahman Hussain

What are Sound Waves?Sound is a

mechanical wave that is an oscillation of pressure

transmitted through a solid, liquid, or gas,

composed of frequencies within the range of

hearing and of a level sufficiently strong to be heard, or the sensation

stimulated in organs of hearing by such

vibrations.

characteristics of Sound

Frequency ,or its inverse, the periodWavelength Wave numberAmplitudeIntensitySpeedDirectionSometimes speed and direction are

combined as a velocity vector; wave number and direction are combined as a

wave vector.

Ultrasound (Ultrasonic Waves)Ultrasound is cyclic sound pressure

with a frequency greater than the upper limit of human hearing.

Although this limit varies from person to person, it is approximately 20

kilohertz (20,000 hertz) in healthy, young adults and thus, 20 kHz serves

as a useful lower limit in describing ultrasound. The reflection signature

can reveal details about the inner structure of the medium, a property

also used by animals such as bats for hunting. The most well known

application of ultrasound is its use in sonography to produce pictures of fetuses in the human womb. There

are a vast number of other applications as well.

Applications of Ultrasound Bats (to detect

their preys)To detect an

unborn babies' sexRadars Dog whistlesUltra sonography Treatment of

muscular painDetect cracks in

metals

The bat Ultrasonic Location System

A short pulse of ultrasound is emitted from a transmitter (a Bat) attached to the object to be located, and we measure the

times-of-flight of the pulse to receivers mounted at known points on the ceiling.

The speed of sound in air is known, so we can calculate the distances from the Bat

to each receiver - given three or more such distances, we have enough

information to determine the 3D position of the Bat (and hence that of the object

on which it is mounted) .By finding the relative positions of two or

more Bats attached to an object, we can calculate its orientation. Furthermore, we

can deduce some information about the direction in which a person is facing, even if they carry only a single Bat, by analysis

of the pattern of receivers that detected ultrasonic signals from that transmitter, and the strength of signal they detected .

Resources

www.wikipedia.orghttp://www.cl.cam.ac.uk

www.youtube.com

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