MULTIPLE REFLECTION OF SOUND

 Multiple reflection : the sound which is reflected more than once. During reflection, sound waves obey the laws of reflections. Sound waves have much longer wavelength than the light waves, The repeated reflection that results in this persistence of sound is called reverberation

USES OF MULTILPE REFLECTION OF SOUND

1.Megaphones or loudhailers, horns, musical instruments such as trumpets and shehanais, are all designed to send sound in a particular direction without spreading it in all directions, as shown in figure below  

In these instruments, a tube followed by a conical opening reflects sound successively to guide most of the sound waves from the source in the forward direction towards the audience. 

2.Stethoscope is a medical instrument used for listening to sounds produced within the body, mainly in the heart or lungs. In stethoscopes the sound of the patient’s heartbeat reaches the doctor’s ears by multiple reflection of sound, as shown in Figure 

3.Generally the ceilings of concert halls, conference halls and cinema halls are curved so that sound after reflection reaches all corners of the hall, as shown in Fig 12.14. Sometimes a curved soundboard may be placed behind the stage so that the sound, after reflecting from the sound board, spreads evenly across the width of the hall figure.