Question

What defines the characteristic quality or timbre of sound?

Answer 1

Characteristic quality.

1. It is the characteristic by which we can distinguish between two sounds that have the same pitch and loudness.
2. Quality is also known as Timbre.
3. Quality indicates property through which be able to distinctly identify the sound produced by two or more instruments playing at the same time

Hence, the ability to distinguish between two sounds that have the same pitch and loudness defines the quality of sound.