It's pretty amazing but Alexander Graham Bell's work towards visualizing sound for deaf people is what prompted his "invention" of the telephone. This section

It's pretty amazing but Alexander Graham Bell's work towards visualizing sound for deaf people is what prompted his "invention" of the telephone. This section [1] talks about the end result but the whole wikipedia article is an interesting read on how his work developed over time. I didn't see anything specific to what I remember from my college class on it but this part hints at it, "pen-like machine that could draw shapes of sound waves on smoked glass by tracing their vibrations." The linked article on Visible Speech [2] may also be of interest describing what Bell's father used to describe sounds phonetically. 1. https://en.wikipedia.org/wiki/Alexander_Graham_Bell#Telephone https://en.wikipedia.org/wiki/Alexander_Graham_Bell#Telephon... 2. https://en.wikipedia.org/wiki/Visible_Speech https://en.wikipedia.org/wiki/Visible_Speech