We might take it as a given that our hearing aids are scarcely visible, can be managed with our smart phones, and can discern between speech and background sound. What we might not realize, however, is that those features are the results of 400 years of experiment, design, and improvement.
Even 5 years ago, hearing aids could not provide the clarity of sound generated at present. To understand why, let’s trace the history of hearing aids—starting today and travelling backwards—to see how hearing aids would have treated your hearing loss in four different years: 2016, 1985, 1940, and 1650.
2016 – Modern Day Digital Hearing Aids
It’s 2016 and you’re looking to treat your hearing loss. You launch an internet browser, search for a community hearing care professional, complete a quick form, and schedule a consultation.
At your hearing assessment, your hearing is screened using state-of-the-art computer technology that precisely measures your hearing. Then, with the help of your hearing care professional, you pick out a hearing aid that suits your requirements from an extensive selection of models.
Then, your hearing specialist programs your new hearing aids to intensify only the sounds and frequencies you have trouble hearing, which results in crystal clear sound without distortion.
If you told someone in the 1980’s that this would be the process, they wouldn’t have thought it was possible.
So what did render it possible? In essence, digital technology.
For the majority of their history, there was no way for hearing aids to differentiate between assorted sound frequencies. Hearing aids would enhance all incoming sound, including background noise, creating distorted sound.
The digital revolution resolved that issue. With digital technology, all information can be converted, saved, and manipulated as permutations of 0’s and 1’s. Digital technology permitted hearing aids to transform sound frequencies into digital information, which could then be categorized in accordance with which sounds should be amplified (speech) and which should be suppressed (background noise).
The first all-digital hearing aid was developed in 1995, and since that time the technology has improved significantly, ultimately to incorporate wireless functionality.
1985 – Transistor Hearing Aids
Now, imagine it’s 1985 and you’re looking to treat your hearing loss. You can forget searching for a local hearing care provider on the internet because the first commercial internet service provider won’t be established until 1989.
You would have to use the phone book, depend on referrals, or drive around the neighborhood to find a hearing care practice.
After scheduling a consultation and having your hearing examined, your choices for hearing aids are very limited. Without the microprocessor and digital technology, hearing aids were built with a series 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 can’t differentiate between different frequencies of sound. Hearing aids receive incoming sound and the transistors function as basic amplifiers, amplifying all sound. So if you’re in a loud area, speech recognition will be virtually 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 confined to vacuum tube hearing aids.
Vacuum tubes consume more power than transistors, so the hearing aids demand 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 enrich speech and can’t filter out background noise.
1650 – Ear Trumpets
Let’s travel all the way back to 1650. There’s no digital technology, no transistors, and no vacuum tubes. As a result, there is no way to convert sound into electrical currents that can be amplified.
With electrical amplification unattainable, your only alternative is mechanical amplification by concentrating and compressing sound into the ear, as with what happens when you cup your hands around your ears.
By 1650, devices were developed that concentrated incoming sound into the ears, and these contraptions were labeled ear trumpets. They were large devices with a conical end that collected sound and a narrow end that focused the sound into the ear.
This would be the only technology obtainable to individuals with hearing loss for the following 250 plus years.
Let’s return to 2016. Over more than 400 years of history, hearing aids have improved from mechanical amplification devices to electrical amplification devices, from vacuum-tube-based to digital-based. They’ve come to be increasingly more compact, lighter, and more efficient and affordable.
They’ve also become much better at differentiating among various 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 significant enhancement 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 enhance natural human hearing, rather than merely restore it?