We might take it as a given that our hearing aids are scarcely detectable, can be controlled with our smartphones, and can distinguish between speech and background sound. What we might not realize, however, is that those functions are the results of 400 years of experiment, design, and development.
Even 5 years ago, hearing aids could not deliver the clarity of sound produced today. To understand why, let’s trace the history of hearing aids—beginning today and going in reverse—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 community hearing care professional, complete a quick form, and book an appointment.
At your hearing exam, your hearing is tested using advanced computer technology that precisely assesses your hearing. Then, with the help of your hearing consultant, you choose a hearing aid that accommodates your needs from a large selection of models.
Then, your hearing practitioner programs your new hearing aids to intensify only the sounds and frequencies you have difficulty hearing, which results in crystal clear sound without distortion.
If you were to tell 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 different sound frequencies. Hearing aids would magnify all inbound sound, including background noise, creating distorted sound.
The digital revolution resolved that problem. With digital technology, all information can be transformed, saved, and manipulated as permutations of 0’s and 1’s. Digital technology enabled hearing aids to transform sound frequencies into digital information, which could then be grouped in accordance with 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 that time the technology has improved tremendously, eventually to include wireless capability.
1985 – Transistor Hearing Aids
Now it’s 1985 and you’re seeking 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 founded until 1989.
You would have to use the yellow pages, rely on recommendations, or drive around the neighborhood to find a hearing care practice.
After reserving a consultation and having your hearing tested, your options for hearing aids are quite restricted. With no microprocessor and digital technology, hearing aids were created with a sequence of transistors. This adds size and increased power requirements, leading to larger batteries and massive hearing aids.
Also, without the advantage of digital technology, the hearing aid cannot distinguish between different frequencies of sound. Hearing aids receive inbound sound and the transistors function as basic amplifiers, amplifying all sound. So if you’re in a noisy area, speech recognition will be nearly impossible.
1940 – Vacuum Tube Hearing Aids
It’s 1940 and you’re considering purchasing a hearing aid. Transistors haven’t been applied to hearing aids yet, so your choices are confined to vacuum tube hearing aids.
Vacuum tubes utilize more power than transistors, so the hearing aids call for larger batteries, making the hearing aids large, heavy, and awkward.
And once again, without digital technology, the hearing aids can only act as basic amplification systems, making all incoming sound louder. The hearing aids can’t enrich 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. 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 alternative is mechanical amplification by focusing and compressing sound into the ear canal, as with what happens when you cup your hands around your ears.
By 1650, gadgets were developed that concentrated inbound 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 concentrated the sound into the ear.
This would be the only technology accessible to people with hearing loss for the next 250 plus years.
Let’s return to 2016. Over the course of 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 come to be considerably more compact, lighter, and more effective and affordable.
They’ve also become better at differentiating among various types of sound, and in amplifying only specific kinds of sound (such as amplifying speech while repressing background noise).
Every generation of hearing aid has produced a significant 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 improve natural human hearing, rather than merely restore it?