Write short notes on reflection of sound waves from plane and curved surface.

Explanation

When the sound waves hit the plane wall. They bounce off in manner similar to that of light. When a loudspeaker is kept at an angle with respect to a wall (plane surface), then the wves coming from the soure (assumed to be a point source) can be treated as spherical wave fronts. Hence, the feflected wave fron on the plane surface is also sperical, such that its centre of survature can be treated as the image of the sound source (virtual or imaginary loud speaker) that can be assumed to be at a position behind the plane surface. These are shown in figures.

The behviour of sound is different when it is reflected from idfferent surfaces- convex or concave or plane. The sound reflected from a convex surface is spread out and so it is easily attenusted and wekened. Whereas, if it is reflected from the concav surface it will convergte at a point and his can be easily amplified. The parabolic reflector (curved reflector) that is used in designing the parabolic mics whcih are known as high directional microphones.
We know that any surface (smooth or rough) can absorb sound for instance, the sound board (concave board) is kept in front of the speaker, in such way that the board reflects the sound waves of the spekar towards the audienece. this method will minimize the spreading of sound waves in all psossible direction in that hall it also enhances the uniform distribution of sound throughout the hall. Hence a person sitting at any position in that hall can hear the sound withoutt any disturbance.