Hearing Aids: The Past, the Present, and the Future
Hearing aids have come a long way since the all-too-obvious contraptions your grandparents grudgingly wore.
The first hearing aid, which debuted in the 17th century, is a far cry from our modern, nearly invisible, high-tech devices. Dubbed “ear trumpets,” these hearing aids were exactly what the name suggests: Funnels shaped like musical instruments which, when held to the ear, helped collect, amplify, and guide sound waves into the ear canal. Ear trumpets were commonly made of sheet metal, but historians have found examples constructed from wood, silver, and even more exotic materials, such as snail shells and animal horns.
It wasn’t until the telephone and microphone were invented in the late 19th century that electronic hearing aids became a real possibility. An electrical engineer named Miller Reese Hutchison, who would become famous for inventing a number of portable electronic devices, introduced the first electrical hearing aid in 1898. Known as the Akouphone, the device used a carbon transmitter and electrical current to amplify weak audio signals. Historical reports claim the Akouphone did successfully treat mild to moderate hearing loss, but it required that wearers be tethered to a bulky, tabletop machine, limiting the device’s practical applications.
The 20th century saw a boom in hearing aid technology. The Vactuphone, a device introduced in 1920, used vacuum tubes and a telephone transmitter to translate speech into an electrical signal. The Vactuphone weighed a mere seven pounds — massive compared to modern hearing aids, but amazingly tiny when viewed alongside the Akouphone.
Miniaturization came to the forefront of hearing aid design during WWII, and Bell Labs’ introduction of the first transistors in 1948 led to tremendous advancements in the level of technology manufacturers could cram into a tiny, portable device. Transistor-based hearing aids also required far less energy than vacuum tube designs, paving the way for the creation of smaller, longer-lasting, less expensive batteries. The 1970s saw the debut of microprocessors, which allowed hearing aids to shrink even further, while dramatically improving audio clarity.
Modern Hearing Aids
The first all-digital, consumer hearing aid — what you’d recognize as a modern hearing aid — was introduced in 1996, and while the basic technology hasn’t changed much since then, the features found in contemporary hearing devices would not have been possible even as recently as five years ago. The latest hearing aids offer unparalleled audio quality, are effectively invisible during use, and can even wirelessly sync with a user’s smartphone to transmit telephone calls and music directly into the ear canal.
If there’s anything more impressive than how far hearing aids have come, it’s the promise of what hearing aid manufacturers have planned for the future. Recently, the United States Food & Drug Administration approved the use of hearing aids that replace traditional digital and analog sound-transmission technology with a smaller, more efficient system that transmits sound vibrations to the ear using precise beams of laser light. More hypothetical designs propose hearing aids that are powered entirely by sunlight in a process that mimics plant leaves, and biotechnological implants that can be updated through the skin, which draw energy from the movements of nearby facial muscles.