Timbre
WordNet
noun
(1) (music) the distinctive property of a complex sound (a voice or noise or musical sound)
"The timbre of her soprano was rich and lovely"
"The muffled tones of the broken bell summoned them to meet"
WiktionaryText
Homophones
Note: The pronunciation /ˈtɪmbə(r)/ is primarily found in US English and considered incorrect in British English.