Thomas Alva Edison developed and demonstrated the keyboard-based speaking telegraph: the concept of text digitally transformed into sound by combining recording and playback in the same instrument. He worked hard to include the correct sound for sibilant words like scythe (sickle), which must not have been easy for someone as nearly deaf as Edison. Essentially, he achieved sound transmission, sound reception, sound recording, and sound reproduction, all in a single sequence connected by his machines.
