timpani, also known as kettledrums. The name comes from the Italian word timpano which is also where we get the word tympanum, or ear drum. The eardrum is a stretched membrane that vibrates when struck by sound waves. Timpani have a membrane called a drum head that is stretched over a frame, and it vibrates when it is struck by a stick called a mallet. That is what makes the big booming sound we know and love.