What are the key concepts/ideas in form and timbre​

“When we think particularly of timbre, we think of the instrument or voice that produces the sound. In order to make a sound one needs three things: a physical object which is vibrating, a medium to carry the vibrations or sound waves, and an ear to hear the sound and turn it into something meaningful.”
-https://ccs.instructure.com/courses/1428874/pages/lecture-1-overview-of-timbre-2

Interprethope this