History of Hearing Aids

Hearing aid (Photo credit: Soitiki)

The origin of hearing aids goes back to the early 17^th century. From the gigantic hearing aids to the 21^st century smaller electronic devices, the concept of amplifying sounds to cure hearing impairment has undergone a sea-change.

Hearing Aids: History

The ‘Metal Ear’ is the first hearing aid instrument created in the early 17^th century. Popularly known as a ‘trumpet’, they were wide at one end to gather sound and narrow at the other end to send amplified sound to the listener. They were made of copper, brass, sea shell, glass and animal horn. This is also the time of ‘bone conduction’ discovery where sound vibrations are transmitted to the brain via the small bones behind the ear.

In 1800, Frederick Rein of London becomes the first full-scale manufacturer of hearing aids. They were smaller in size than the earlier century. They were mostly designed as decorative accessories and embedded with clothing, bouffant hairstyles, collars and elaborate headwear. The instruments were portable but not too comfortable. The royalty had aids inbuilt with the throne!

Electronic Hearing Aids

The concept of electronic hearing aids comes into being with the construction of Graham Bell’s telephone is 1876. It shows how acoustic signals can be transmitted electronically, while controlling frequency, sound distortions and loudness.

Miller Reese Hutchinson creates the first electric hearing aid in 1898, known as the Akouphone. Here, the device uses a carbon transmitter to capture a weak signal and amplify it to a strong signal. Later, the Siemens Company creates the first amplified hearing aids on a massive scale in 1913. The speaker fits the ear and the device is about the size of a cigar box.

In 1920, Naval Engineer Earn Hanson patents the first vacuum tube hearing aid known as the Vactuphone. The Vactuphone uses the telephone to convert speech into electric signals, and the signals amplified to reach the receivers’ ear. In the 1920s and the 30s, companies like Western Electric successfully reduces the size of vacuum tubes and they become more popular with the masses.

Hearing Aids: Mid-20^th & 21^st Century

Hearing aid (Photo credit: Soitiki)

The technological improvements of the World War II help the hearing impairment corrective device to reach a modern form. The idea to miniaturize the device becomes popular. The invention of the transistor in the 1950s changed the perception of hearing aids completely. In fact, transistors are used in hearing aids first and then in transistor radios. The manufacture of silicon transistors helps to reduce the size further. From body aids to a device fixed behind the ear to one located within the ear canal, the size continues to reduce.

The introduction of digital technological in the mid-1990s helps further in amplifying, filtering and directing the sound to the listener, as needed. They are customized to suit the lifestyle of the user. For instance, soft amplification at home and targeted amplification when in noisy places like restaurants.

The hearing impairment correction devices of the 21^st century are ever more powerful, almost invisible, require less maintenance, have higher life span, microscopic protective shields and are lighter. They are “intelligent” devices to adapt with changing surrounding.