The first modern hearing aid was produced during the 1800s by companies in Philadelphia and Germany. They used technology based on the carbon transmitter and electrical amplification advances of Thomas Edison and Alexander Graham Bell. The first carbon-type hearing aid was developed in 1989 by the Dictograph Company.
The first electrical hearing aid, which implemented usage of a battery and a carbon transmitter, was patented by Miller Reese Hutchison in Alabama. The first hearing aid models before the use of carbon transmitters were large ear trumpets where one end was large, used to collect noise, before funneling into a small tube that fit into the ear.