The modifications aimed to make the analogy between technology and nature more literal. Bell's ear phonautograph. From the phonautograph, Bell gained a tactile, 'hands-on' understanding of how speech was translated into an undulating wave by the vibrations of the bones of the ear. From his multiple telegraph experiments, Bell gained a similar understanding of how the vibrations of a reed or a combination of reeds could be translated into what he called an undulating electric current that would reproduce the sinusoidal pattern of the sounds. At the urging of Gardiner Hubbard, Bell had begun keeping a notebook at around the time he applied for his patent.
Notebooks are one of the ways in which inventors establish priority for their ideas.
On the left was an electromagnet, suggesting that the bones would serve a function similar to the steel reed he had so often placed over an electromagnet to transmit and receive complex tones. On the right was an iron cylinder attached to the bones and this vibrated in the center of a magnetized helix with an iron core. Make armature after the shape of the ossacles. The ear analogy provided Bell with a mental model that suggested possibilities and problem areas. Bell knew he could not include the ossicles in an actual speaking telegraph.