Question

What do you understand by the term quality of sound?How is quality imparted to a sound of some particular pitch and loudness?

Answer 1

sounds was a wave this is the quality of hear like I can speak very loudly in Mountain range the sound come again this was a particular pitch

Answer 2

Here is your answer-
Sound "quality" or "timbre" describes those characteristics of sound which allow the ear to distinguish sounds which have the same pitch and loudness.