Question

Blank refers to the unique tone quality of a particular voice or instrument

Answer 1

The term you're looking for is "timbre." Timbre is what distinguishes different types of sound production, such as the difference between a violin and a flute, even when they are playing the same pitch. It encompasses the unique tonal quality and color of a sound, which can be influenced by factors like the instrument's material, shape, and the technique used to produce the sound.