History Of Hearing Aids
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Speak up--on the history of the hearing aid, which is like almost every other feature of the human creation, our natural ability to hear what’s going on in the world around us, is not the best. Few men have eyes that see as keenly as a hawk, few can smell as well as the blood-hound or other creatures, and no one can run as fast as a horse (that’s why we have cars)! Where the human sense of hearing is concerned, it has been the same forever---and for almost as long, inventive people, physicians and others, have devised ways to assist those who might not hear as well as others, often the elderly.Every species of animal has a different ‘threshold of hearing’, and it depends on more than just cocking your head and cupping your ear. Various frequencies of sound cause a different response, and your inner-ear and mental apparatus will ‘tune’ to the frequencies you hear the most, such as human speech. So, impairment in your hearing means that your ear, nerves, and the auditory-portion of your brain, do not perceive sounds in the ordinary range for other people. And as we know, this circumstance in life does not indicate any lack of intelligence, education or attention span. Indeed, many of history’s most respected scholars and wise-men have suffered from poor hearing.
The ‘hearing aid’ specifically, however, appeared in history like many other modern conveniences, through long periods of trial-and-error. Records from as early as 1588 described by the writer Giovanni Battista Porta, show that healers of that time fashioned ‘hearing aids’ of wood, shaped like the ears of animals known for acute hearing---as if some of that natural, animal ability would rub off on the hard-of-hearing from that early period. Ear-trumpets, such as elongated tubes with a funnel-shaped end, were commented on by Francis Bacon in 1627. Medical and surgical approaches were also tested through 1878, when doctors learned to repair the perforated tympanic ‘ear-drum’ membrane. Then in 1898, about the time electricity came into use, the first commercial hearing aid, called a ‘carbon-type’, was produced in the U.S. by the Dictograph Company.
Inventor Thomas Alva Edison, credited with thousands of inventions and among the first to realize the potential of electricity, was himself ‘hard-of-hearing’ from childhood, and became technically deaf in his teens. Edison’s patent for the ‘carbon-transmitter’, which translated sound into electrical signals, was the basis of the Dictograph Company device. Additionally, Alexander Graham Bell, credited with inventing the telephone, was concerned with deafness and opened a school for teachers of the deaf in 1872. While working to invent a hearing aid, he instead invented the telephone, so widely used today. In 1899, the Akouphone Company patented the first practical electric hearing aid, again using the carbon-transmitter, and a microphone with a battery. It retailed for $400 and was large enough to require it’s own table for the user.
By 1952, the first transistor hearing aids were developed. These hybrids featured both vacuum tubes and a transistor, considered advanced before the digital-computerized age. These types were developed and refined over many years, until very sophisticated and successful models became available, which were also small and attractive. By the 1960’s, the miracle of the transistor allowed hearing aid designers to create ‘over-the-ear’ or ‘behind-the-ear’ models that were considered a great improvement. These were later followed by features like directional microphones, and integrated circuitry that helped users to distinguish between speech and background noises. Tiny batteries for ‘in-the-canal’ aids with analog sound-systems that were almost completely hidden from view were also developed. Then in the 1980’s, with the introduction of lithium batteries, hearing aids went digital like the rest of the world, and these ‘hearing helpers’ became almost like mini-computers.
By 1984 in America, the Food and Drug Administration approved the first so-called cochlear implant for pubic use, advancing the technology for improved hearing for the impaired even more. This procedure, however, were controversial among the deaf community. But other advances went forward for the more-traditional aids, like dual-processing, multi-tone banding to recognize speech components like vowels and consonants, and advanced feedback controls.
So, from the days when a wooden-funnel shaped like the ear of a fox or hound substituted for better hearing, to an era when the elderly might have held a silver or brass ‘trumpet’ to his ear in the dinner parlor when guests wanted to chat, and through to the time when electricity was used, and then developed into quality hearing-aids that really worked very well for millions of people---the quest to assist the human-creature with his poor hearing, may well have been the envy of all sorts of animals and species with much better ears than ours. All sorts of devices have been used---including tubes and domes of fine metals that amplified the sounds of stage-performances or announcements in the throne-rooms of kings, as well as things like the so-called ‘bone-conductor’, developed in 1933, which transmitted sound directly through the bones of the skull. And the wonderful world of hearing has never been the same.
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