Conversation so far:
What was Alexander Graham Bell's first experiment with sound?
a remarkably lifelike head that could "speak", albeit only a few words.
How old was he when he made the head?
CANNOTANSWER.
What inspired him to make the head?
Their father, highly interested in their project, offered to pay for any supplies and spurred the boys on with the enticement of a "big prize" if they were successful.

Question: What year did they make the head?
Self-contained rewrite: What year did Alexander Graham Bell make the head?