A Short History of Hearing Aids
We might take it as a given that our hearing aids are scarcely visible, can be managed with our smart phones, and can differentiate between speech and background sound. What we might not recognize, however, is that those functions are the products of 400 years of experimentation, design, and development.
Even 5 years ago, hearing aids could not generate the clarity of sound produced today. To see why, let’s trace the history of hearing aids—beginning 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 – Contemporary Digital Hearing Aids
It’s 2016 and you’re looking to address your hearing loss. You launch a web browser, search for a local hearing care professional, fill out a brief form, and arrange a consultation.
At your hearing exam, your hearing is screened using state-of-the-art computer technology that precisely assesses your hearing. Then, with the assistance of your hearing care specialist, you pick out a hearing aid that complements your requirements from a large selection of models.
Then, your hearing consultant programs your new hearing aids to enhance only the sounds and frequencies you have difficulty 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 thought it was possible.
So what did render it possible? In a nutshell, digital technology.
For the majority of their history, there was no way for hearing aids to distinguish between assorted sound frequencies. Hearing aids would intensify all inbound sound, including background noise, creating distorted sound.
The digital revolution addressed that issue. With digital technology, all information can be transformed, stored, and manipulated as permutations of 0’s and 1’s. Digital technology permitted hearing aids to convert sound frequencies into digital information, which could then be grouped based on 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 then the technology has improved exponentially, eventually to include wireless capability.
1985 – Transistor Hearing Aids
Now, imagine it’s 1985 and you’re planning to treat your hearing loss. You can forget about searching for a local hearing care provider on the internet because the first commercial internet service provider won’t be established until 1989.
You’d have to use the phone book, depend on recommendations, or drive around the neighborhood to find a hearing care practice.
After scheduling an appointment and having your hearing checked, your options for hearing aids are very limited. Without the microprocessor and digital technology, hearing aids were manufactured with a series of transistors. This adds size and increased power requirements, resulting in bigger batteries and massive hearing aids.
Additionally, without the benefit of digital technology, the hearing aid can’t distinguish between various frequencies of sound. Hearing aids receive incoming sound and the transistors behave as basic amplifiers, amplifying all sound. So if you’re in a noisy room, speech recognition will be practically impossible.
1940 – Vacuum Tube Hearing Aids
It’s 1940 and you’re interested in buying a hearing aid. Transistors haven’t been applied to hearing aids yet, so your options are limited to vacuum tube hearing aids.
Vacuum tubes consume more power than transistors, so the hearing aids require larger batteries, making the hearing aids big, heavy, and cumbersome.
And once again, without digital technology, the hearing aids can only act as simple amplification systems, making all inbound 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 out of the question, your only option is mechanical amplification by concentrating and compressing sound into the ear, much like what takes place when you cup your hands around your ears.
By 1650, gadgets were developed that focused inbound sound into the ears, and these contraptions were called ear trumpets. They were large devices with a conical end that collected sound and a narrow end that concentrated the sound into the ear.
This would be the only technology accessible to those with hearing loss for the next 250 plus years.
Let’s return to 2016. Throughout more than 400 years of history, hearing aids have advanced from mechanical amplification devices to electrical amplification devices, from vacuum-tube-based to digital-based. They’ve become significantly more compact, lighter, and more efficient and affordable.
They’ve also become much better at distinguishing between various types of sound, and in amplifying only specified kinds of sound (like amplifying speech while suppressing background noise).
Each generation of hearing aid has generated a major improvement over the previous generation. The question is, what’s the next great milestone in the history of hearing aids?
Will we soon be able to enhance natural human hearing, rather than simply restore it?