Quality or timbre of sound is instrumental in distinguishing 2 sounds with
Same pitch and same loudness but different waveforms
Sounds may be generally characterized by pitch, loudness, and quality. Sound "quality" or "timbre" describes those characteristics of sound which allow the ear to distinguish sounds which have the same pitch and loudness. Timbre is a general term for the distinguishable characteristics of a tone. Timbre is mainly determined by the harmonic content of a sound. of sound is the property of the sound by which one can distinguish between 2 similar notes (same pitch & loudness) from 2 different instruments due to difference in their waveforms.