Alexander Graham Bell is notorious for his invention of the telephone. He also had a great desire to help the deaf. He spent a number of years researching and then trying to design communication devices for them. Although he never actually created the hearing aid, his development work was not wasted as the knowledge he gained helped in the invention of his telephone. His telephone inspired an American, Miller Hutchinson of New York City, to further the development of the hearing aid.
In 1902, Hutchinson applied for a patent on his battery-powered hearing aid. In operation it worked in a very similar way to the telephone. The device converted sounds into electrical signals, amplified them and then transferred them back into sounds that were considerably louder than the original ones. Soon afterwards, the battery-powered hearing aid replaced the primitive ear trumpets which were being used at that time to help those who had hearing problems. The only drawback of Miller Hutchinsons aid was that it was extremely bulky. With the technology available today, it has been possible to miniaturize the hearing aid by using transistors and coin-sized batteries.
