Hearing Aids

Early History

Hearing aids were first mentioned in print in 1551 by Gerolamo Cardano, an Italian physician, philosopher, and mathematician, who described them in De Subtilitate as consisting of the rod or shaft of a spear that conducted sounds when held between the teeth. Giovanni Battista Porta, an Italian physician, scientist, and cryptographer, wrote in Magia Naturalis (1588) that hearing aids were being made of animal-shaped wood. By the mid-17th century, hearing aids had progressed to the familiar trumpet shape. Athanasaius Kircher (1602–1680), a Jesuit scholar, took credit for inventing the trumpet, which amplified sound as others spoke directly into it. In 1670, an improved version of the speaking trumpet was introduced by Sir Samuel Morland (1625–1695), a noted inventor, mathematician, and spy. He subsequently introduced brass and copper models.

In 1757, a German merchant inadvertently rediscovered the ability of bone as a sound conductor when he leaned against a harpsichord and discovered that he was able to hear music. He then experimented with a piece of hard wood held between his teeth and those of a speaker, finding that he could carry on a conversation. By the end of the century, trumpets in funnel or conical shapes had become common, and collapsible models were made available. It was not until 1800, however, that F. C. Rein and Son of London began commercial manufacturing of hearing aids. In 1808, the German inventor Johann Nepomuk Mälzel, the inventor of the metronome, began making ear trumpets for composer Ludwig van Beethoven.

[Page 458]In 1836, the first patent for a hearing aid was assigned in Great Britain to Alphonsus William Webster. Instead of the trumpet, the device curved around the ear. In 1855, the first American patent was assigned to Edward G. Hyde. In 1867, the London firm T. Hawksley, Ltd. began making hearing devices that could unobtrusively be hidden in clothing. Major commercial production of hearing aids in the United States began in 1873 with the establishment of E. B. Meyrowitz. The following year, Dr. Constantin Paul introduced a binaural conversation tube that consisted of a headband and Y-shaped connections attached to the ears. In 1885, Enoch Henry Currier introduced a teaching aid for deaf students in which the teacher spoke into a bell leading to tubes in the ears of the students. In 1887, American James A. Maloney invented the diaphragm earpiece. By 1892, the first electric hearing aid had been invented in New York, but it was never marketed.

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