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The earliest appearance of these instruments is unknown, but they became very popular in the 1800's and a few were made in Europe as late as the 1960's. These hearing aids have a unique appearance and were often cumbersome to use. They also provided limited benefit, particularly for those with more than a mild to moderate hearing loss.

London Dome

Hand engraved sterling silver. Made by F.C. Rein in London, England about 1850. This is the oldest item in the museum. The dome measures 7.1 cm high by 6.8 cm in diameter.

Hawksley Ear Dome

This ear dome was made in about 1890 by Hawksley of England. Made of brass. Bell measures 7.2 cm in diameter by 6.6 cm high. The shape and size of the dome will influence its resonant characteristics.

Ear Trumpet

This ear trumpet is made of tin. Black tape, painted silver, covers the area where the trumpet is held.

Clarvox Lorgnette Trumpet

This lorgnette is made of artificial tortoise shell. The earpiece (the short, curved end) pivots for more comfortable positioning. It was made in France.

Hawksley Auricle

Hawksley B 93. Auricle worn on headband or in a bonnet. The tubing is adjustable in two places. Made of metal with an optional cloth covering (as shown). Made by T. Hawskley Ltd., London, England about 1915.

Stethoclare Table Model

Pilling "Stethoclare Table Model". Made about 1914. The open end pointed toward the speaker, and a tube led from the back portion to the ear for listening. Cone measures 11.6 cm in diameter by 12.0 cm deep.

Plantagenet

Dates from 1960 and may still be sold in Europe. Collapsible ear scoop made of plastic. Older models were enameled metal or leather covered.

Hearing Fan

The hearing fan was used by holding the fan between the teeth. Fan tension could be adjusted by strings attached to the back of the fan. Sound waves striking the fan were conducted through the teeth, and thus the skull bones, to stimulate the cochlea. It was not a very efficient means of amplification even for strictly conductive hearing losses.

Twin Fone

Twin-Fone, made by the American Earphone Company. Not a hearing aid, but rather a mechanical device to allow a second person to listen to a telephone conversation. The extra parts are to modify it for a French styled telephone.

Otophone 2 D

Made by Meyrowitz in New York City about 1887. Measures 92.5 cm long by 1.9 cm diameter. This listening tube has a diaphragm earpiece.

Hybrid hearing aids use a combined digital/analog circuitry. The first patent for hybrid technology was received in 1977 and the first commercial release of a digital chip to be integrated in an analog hearing aid occurred in 1986. These hearing aids have greatly increased our flexibility in fitting the hearing-impaired population.

Unlike the carbon instruments, these had adequate power for severe hearing losses but were also usable by persons with a lesser loss. The first one appeared in 1921, but this type did not become practical until the early 1930's, and did not appear in a wearable version until 1934. Vacuum tube aids required two batteries, so costs were rather high.

A.) Ear Receiver
B.) Microphone/Amplifier
C.) Batteries

Tel-Audio

Table model vacuum tube hearing aid. Has a large external microphone and earphones. This is probably the first hearing aid with a telecoil! It plugged into the wall, or had optional battery power. Made in 1936.

Vactuphone

Globe "Vactuphone". VACuum TUbe TelePHONE. Made to order by Western Electric Company for Globe. The first hearing aid to use a vacuum tube! Case was 18.4 cm x 10.0 cm x 18.3 cm. Fist made in 1921. Model shown is the commercial model. The engineers' model (not shown) was not leather covered and did not have a name and patent plate. Also shown is the single vacuum tube used in the hearing aid.

1930s Vacuum Tube Hearing Aid

Vacuum tube (that is, electronic) hearing aids were becoming popular, but not yet a serious competitor for carbon aids. They were still too large and consisted of two parts (a battery pack and separate amplifier). They did not become small and wearable in a practical manner until late 1930's. They required one battery to warm up the vacuum tube filament and a second battery to power the amplifier.

Mono-Pac Melody

Beltone Mono-Pac "M" (Melody). One piece vacuum tube hearing aid. Still needed two batteries, but no longer external. Available with the optional broach styled microphone shown here. Made in 1950.

Sonotone 533

Sonotone 533, made in 1942. This aid contains 3 vacuum tubes. This is a very flexible hearing aid! It is changeable between air conduction and bone conduction (bone shown). Two battery options were also available, with the dual battery option shown. Also shown is the additional cord available for air conduction receivers. Case measures 5" x 2 7/16" x 1".

These are based on the telephone principle; however, Alexander Graham Bell had nothing to do directly with their development. These appeared first in limited quantities in a table model about 1899, but in wearable and practical instruments beginning only in 1902. Carbon aids were popular through the 1940's. Most of these used a rather large 3-volt or 6-volt battery but did not have enough power to assist those with more than a moderate hearing loss.

A.) Microphone
B.) Headset
C.) Battery

Confessionaire

This was a hearing aid used by priests during confession. The user would hold the receiver (attached by the cord) to his ear and hold the rest of the device toward the speaker. Made by the Confessional Hearing Aid Company of Port Washington, New York.

1920s Carbon Hearing Aid

Carbon (that is, electric) hearing aids were a decade old and becoming popular, but non-electric devices were still used by many. Carbon aids required a single (but large) 3-volt or 6-volt battery.

Acousticon LT

Made about 1905. There are four microphones in a wooden case. Measures 11.3 x 45.4 x 5.1 cm. Used for listening in groups, such as in church.

Digital hearing aids utilize digital signal processing (DSP) chips, which became available in 1982. Experimental body-worn digital hearing aids were developed soon after.

Project Phoenix was established in 1984 and commercially produced the first wearable DSP hearing aid in 1988. Unfortunately, it was large (the combined size of a body aid and a behind-the-ear aid) and expensive and thus not a financial success. As recently as April 1996, the first fully digital behind-the-ear and in-the-ear instruments were made commercially available with a computing capacity of 40 million instructions per second. Digital hearing aids operate on either an open or closed platform (more or less flexibility) dependent upon the manufacturer.

As technology continued to improve, digital programmable hearing aids were developed. This latest development has given us hearing aids that are capable of adjusting to sound input on their own, thus eliminating the need for a separate remote control. These hearing aids look no different from transistor hearing aids, and are available from behind-the-ear styles down to completely-in-the-canal styles. Often these hearing aids have a push-button volume control or no volume control; the hearing aid adjusts itself as needed depending on the listening environment.

The current era of DSP and programmable hearing aids holds promise for increased sound quality and maximum flexibility in fulfilling the unique needs of the hearing impaired population.