• Basic Sound Concepts:-
• Sound is produced by the vibration of matter.
• During the vibration, pressure variations are created in the air surrounding it.
• The pattern of the oscillation is called a wave form.
• The waveform repeats the same shape at regular intervals and this portion is called a period.
• Since, sound waves occur naturally, they are never perfectly smooth or uniformly periodic.
• However sounds that display a recognizable periodicity tend to be more musical than those that are non-periodic.
• For Ex: periodic sound sources are musical instruments, vowel sounds, and the whistling wind and bird songs.

Non-periodic sound sources include unpitcthed percussion instruments, coughs and sneezes and rushing water