We hear various kinds of sound in our daily life, pleasant sounds called the musical sounds, unpleasant sound called the noise, loud sound, high pitched sound etc.
Sound is the form of energy propagated as waves which our ears receive.
Sound can propagate not only through gases but also through solids and liquids. Some materials like air, water, iron etc can easily transmit sound energy from one place to another.
As wavelength is the distance covered during one oscillation and frequency is the number of oscillations per second, the product of the wavelength and frequency would give us the wave velocity.
The speed of sound depends on the properties of the medium through which it travels.
According to the law of reflection of sound the directions in which the sound is incident and reflected make equal angles with the normal to the reflecting surface and the three lie in the same plane.
Sound waves suffer reflection from the large obstacles. As a result of reflection of sound wave from a large obstacle, the sound is heard which is named as an echo.
The sound waves having frequencies less than the audible range are called infrasonic waves.
It is used for medical diagnosis and therapy and also as a surgical tool.Bats and porpoises use ultrasound for navigation and to locate food in darkness.
One of the most important applications of the reflection of sound is oceanographic studies. For this purpose, we use a system called the SONAR. The SONAR is abbreviated form of Sound Navigation and Ranging.
Echolocation is a method of sensory perception by which certain animals orient themselves to their surroundings, detect obstacles, communicate with others and find food.
Ears are extremely sensitive device with the help of which we are able to hear.