We may take it as a given that our hearing aids are scarcely noticeable, can be controlled with our cell phones, and can discern between speech and background sound. What we may not realize, however, is that those functions are the products of 400 years of research, design, and improvement.
Even as early as 5 years ago, hearing aids could not produce the clarity of sound generated at present. To understand why, let’s follow the history of hearing aids—starting today and travelling in reverse—to observe how hearing aids would have handled your hearing loss in four different years: 2016, 1985, 1940, and 1650.
2016 – Contemporary Digital Hearing Aids
It’s 2016 and you’re looking to address your hearing loss. You open up an internet browser, search for a community hearing care professional, complete a brief form, and arrange an appointment.
At your hearing exam, your hearing is analyzed using advanced computer technology that accurately evaluates your hearing. Then, with the assistance of your hearing care professional, you decide on a hearing aid that meets your requirements from a vast selection of models.
Then, your hearing professional programs your new hearing aids to magnify only the sounds and frequencies you have trouble hearing, producing crystal clear sound without distortion.
If you told someone in the 1980’s that this would be the process, they wouldn’t have believed it was possible.
So what did render it possible? In short, digital technology.
For most of their history, there was no way for hearing aids to differentiate between assorted sound frequencies. Hearing aids would amplify all inbound sound, including background noise, producing distorted sound.
The digital revolution solved that issue. With digital technology, all information can be altered, stored, and manipulated as combinations of 0’s and 1’s. Digital technology permitted hearing aids to transform sound frequencies into digital information, which could then be categorized according to which sounds should be amplified (speech) and which should be restrained (background noise).
The first all-digital hearing aid was developed in 1995, and since then the technology has improved significantly, eventually to incorporate wireless capability.
1985 – Transistor Hearing Aids
Now it’s 1985 and you’re looking to treat your hearing loss. You can forget browsing for a local hearing care provider on the internet because the first commercial internet service provider won’t be established until 1989.
You’d need to use the yellow pages, depend on referrals, or drive around the neighborhood to find a hearing care practice.
After reserving a consultation and having your hearing screened, your options for hearing aids are quite limited. Without the microprocessor and digital technology, hearing aids were engineered with a collection of transistors. This adds size and higher power requirements, leading to bigger batteries and massive hearing aids.
Also, without the advantage of digital technology, the hearing aid cannot differentiate between various frequencies of sound. Hearing aids receive inbound sound and the transistors behave as basic amplifiers, amplifying all sound. So if you’re in a noisy room, speech recognition will be just about impossible.
1940 – Vacuum Tube Hearing Aids
It’s 1940 and you’re considering acquiring a hearing aid. Transistors haven’t been applied to hearing aids yet, so your choices are restricted to vacuum tube hearing aids.
Vacuum tubes utilize more power than transistors, so the hearing aids require larger batteries, making the hearing aids large, heavy, and cumbersome.
And once again, without digital technology, the hearing aids can only act as straightforward amplification devices, making all incoming sound louder. The hearing aids cannot enhance speech and can’t remove background noise.
1650 – Ear Trumpets
Let’s go all the way back to 1650. There’s no digital technology, no transistors, and no vacuum tubes. That means no way to transform sound into electrical currents that can be amplified.
With electrical amplification out of the question, your only alternative is mechanical amplification by concentrating and compressing sound into the ear canal, such as what happens when you cup your hands around your ears.
By 1650, products were developed that concentrated inbound sound into the ears, and these contraptions were called ear trumpets. They were prominent gadgets with a conical end that collected sound and a narrow end that concentrated the sound into the ear.
This would be the only technology offered to people with hearing loss for the following 250 plus years.
Let’s return to 2016. Over more than 400 years of history, hearing aids have grown from mechanical amplification devices to electrical amplification devices, from vacuum-tube-based to digital-based. They’ve become increasingly smaller, lighter, and more efficient and affordable.
They’ve also become much better at differentiating between different types of sound, and in amplifying only certain kinds of sound (like amplifying speech while repressing background noise).
Every generation of hearing aid has made a major upgrade over the previous generation. The question is, what’s the next major milestone in the history of hearing aids?
Will we soon be able to improve natural human hearing, rather than merely restore it?