It was a revolution in communication and one that lay the foundation for technological advances such as the smart phone. In 1876, Alexander Graham Bell patented the telephone. It was not his only scientific contribution, albeit his most famous one.
Bell witnessed the impacts of hearing loss firsthand. His mother lost her hearing as a child and his wife was deaf. Additionally, his grandfather, father, and brother all worked in areas associated with speech and hearing. This exposure and subsequent interest led him to develop the first audiometer in 1879. Around that same time German physician, Hermann Ludwig Ferdinand von Helmholtz, invented an electrically driven tuning fork to measure hearing sensitivity.
Read the whole story in Canadian Audiologist.