timbre

This term describes the sonic fingerprint of an instrument or voice. It is the reason a piano and a flute sound different even when they play the exact same note at the same volume. It captures the texture, color, and richness of a sound, often described using sensory adjectives like bright, dark, nasal, or breathy. In professional audio engineering and music theory, it is treated as a distinct property of sound, separate from frequency (pitch) and amplitude (volume). While pitch tells you which note is being played, timbre tells you who or what is playing it.