The uses and laws of reflection of sound waves
The reflection is the change in the direction of a wavefront at a interface between two different media so that the wavefront returns into the medium from which it originated such as the reflection of light , sound and water waves .
The sound waves can be reflected by large , hard , smooth , vertical and far way surfaces such as the walls , the buildings and the cliffs , where the echoes are produced by the reflections of sound from these surfaces .
The reflection of sound
The sound reflection is the return of the sound waves in the same direction due to hitting a reflecting surface ( such as a wall ) .
What are the laws of reflection of sound ?
The reflection of sound waves is governed by two laws known as the two laws of sound reflection , The first law of reflection of sound waves is the angle of incidence = the angle of reflection .
The incident sound ray , the reflected sound ray and the perpendicular line from the point of incidence on the reflecting surface , all lie on the same plane , perpendicular to the reflecting surface .
The sound ray is the direction of the line propagation of sound wave , The angle of incidence of sound ray is the angle between the incident sound ray and the line perpendicular to the reflecting surface at the point of incidence .
The angle of reflection of sound ray is the angle between the reflected sound ray and the line perpendicular to the reflecting surface at the point of incidence , When a sound ray is incident perpendicular to a reflecting surface , it reflects on itself because the angle of incidence = the angle of reflection = 0 .
It is very important to put a piece of moquette or rubber under the vibrating washing machine , while getting rid of water to absorb the noise produced due to vibration instead of its reflection from the glistening surfaces of walls .
The ceilings and the walls of broadcast studios are covered with rubber or felt to absorb the sound and prevent its reflection .
Uses of reflection of sound
The reflection of sound is used in many devices as the megaphones , the horns , the musical instruments like the trumpet , the shehnais , etc , The ceilings of the cinema halls and the auditoriums are curved so that the sound after multiple reflection reaches all parts of the hall .
Doctors listen to the sounds from the human body through a stethoscope which is used to hear the sounds of internal organs of a patient for the diagnostic purposes .