Hearing Aid History
The first hearing aids were enormous, horn-shaped trumpets with a large, open piece at one end that collected sound. The trumpet gradually tapered into a thin tube that funneled the sound into the ear.
The development of the modern hearing aid might not have been possible had it not been for the contributions of two of the greatest inventors of the late 19th and early 20th centuries. Alexander Graham Bell electronically amplified sound in his telephone using a carbon microphone and battery -- a concept that was adopted by hearing aid manufacturers. In 1886, Thomas Edison invented the carbon transmitter, which changed sounds into electrical signals that could travel through wires and be converted back into sounds. This technology was used in the first hearing aids.
The Industrial Revolution allowed for the mass production of hearing aids and created a new middle class that could afford the technology. In the 1800s, several companies, including George P. Pilling and Sons of Philadelphia, and Kirchner and Wilhelm of Stuttgart, Germany, produced their own versions of hearing aids. In 1898, the Dictograph Company introduced the first commercial carbon-type hearing aid. A year later, Miller Reese Hutchison, of the Akouphone company in Alabama, patented the first practical electrical hearing aid, which used a carbon transmitter and battery. It was so large that it had to sit on a table, and it sold for $400.
In the 1920s, vacuum tubes were introduced to hearing aids, which made sound amplification more efficient, but enormous batteries still made them cumbersome.
1952 ushered in the age of the transistor hearing aids. The addition of these simple on/off switches finally enabled the advent of a smaller hearing aid. Early transistor hearing aids were designed to fit within the frames of eyeglasses. Later, they were adapted to fit behind the ear. The first transistor hearing aid to hit the market in late 1952 was sold by Sonotone for $229.50.
In the 1990s, hearing aids went digital. Sound quality improved and became more adjustable. Also during this time, programmable hearing aids were introduced.
At the turn of the 21st century, computer technology made hearing aids smaller and even more precise, with settings to accommodate virtually every type of listening environment. The newest generation of hearing aids can continually adjust themselves to improve sound quality and reduce background noise.
For more information on hearing aids and related topics, check out the links on the following page.
Related HowStuffWorks Articles
More Great Links
- AAO-HNS, "Frequently Asked Questions About Hearing Aid Development." http://www.entlink.net/history/exhibits/Hearing-Aid-FAQ.cfm
- Alpiner, Jerome G.; Mulvey, Megan; Smith, Randall D. "The Hearing Aid Decision: Answers to Your Many Questions." Ramie, 2007.
- AmericaHears Inc., "Looking at the History of Hearing Aids: The Past, Present, and Future of Hearing Aid Technology." http://hearing-aids.americahears.com/aid-technology.html
- American Academy of Otolaryngology -- Head and Neck Surgery, "Buying a Hearing Aid." http://www.entnet.org/healthinfo/hearing/hearing_aid.cfm
- American Academy of Otolaryngology -- Head and Neck Surgery, "Cochlear Implants." http://www.entnet.org/healthinfo/ears/cochlear-implant.cfm
- American Speech-Language-Hearing Association, "Hearing Aids." http://www.asha.org/public/hearing/treatment/hearing_aids
- Carmen, Richard. "The Consumer Handbook on Hearing Loss and Hearing Aids: A Bridge to Healing." Auricle Ink, 2004.
- Cochlear Implants http://www.fda.gov/cdrh/cochlear/
- Comarow, Avery. "Good Vibrations; They're Still Hearing Aids. But they're Better-and Smaller."
- Dillon, Harvey. "Hearing Aids." Thieme Medical, 2001.
- Discovery Channel, "How It's Made: Hearing Aids."
- Ear Info, "Frequently Asked Questions." http://www.earinfo.com/hearingloss.html
- Federal Trade Commission, "Sound Advice on Hearing Aids."
- Focus on Healthy Aging, "Choosing the Right Hearing Aid." June 2007.
- MayoClinic, "Hearing Aids: How to Choose the Right One."
- Medical News Today, "Alternative Treatment Brings Hearing to Both Ears." August 2, 2007. http://www.medicalnewstoday.com/printerfriendlynews.php?newsid=78423
- Medical News Today, "Duke University Study Finds Hearing Aids are Underused." June 3, 2006. http://www.medicalnewstoday.com/printerfriendlynews.php?newsid=44479
- Myers, David G. "A Quiet World: Living with Hearing Loss." Yale University Press, 2000.
- National Institute on Deafness and Other Communication Disorders,
- "Hearing Aids." http://www.nidcd.nih.gov/health/hearing/hearingaid.asp
- Smoski, Walter J. "Hearing Aids." Last updated April 16, 2007. http://www.emedicine.com/ent/topic478.htm
- U.S. News & World Report, May 22, 2006, Vol. 140, Issue 19, pp. 53-55.