PITCH OF SOUND: The characteristic of sound by which we can distinguish between shrill sound and grave sound of same loudness is called pitch. Pitch of sound depends upon the frequency of the vibrating body the greater the frequency higher will be the pitch of sound. Sound produced by dogs, donkeys, beating of drums, frogs and man are grave and so these are of low pitch (i.e. of low frequency). On the other hand the sounds produced by rats, cats, small birds and women are shrill ( i.e. of high frequency) and hence of high pitch.

 

 

Frequency can be demonstrated by the experiment. Rotate the wheal of bicycle and hold a piece of cardboard in your hand with its free end touching the spokes of the rotating wheel. The cardboard on touching the spokes will start vibration and will produce grave sound. But when the speed of the rotating wheel is increases the frequency of vibration of cardboard increases and this will now produce shrill sound.

 

QUALITY OF SOUND:

 

 

The property of sound by which two sounds of same loudness and pitch can be distinguished from each other is called quality of sound. It is also known as timber of the sound. By the means of quality of sound we can distinguish the voices of our relatives and friends and also the sound produces by different musical instruments like violins, flutes, sitar and pianos. The quality of sound can be easily understood from the wave form of the sound.

 

 

For example the wave form of sound produced by tuning fork is different from the waveform sound produced by the piano. The loudness and pitch of these two sounds are same but there are waveforms are different due to which both there sound has different quality of sound.