The Inner Life of Hearing Aids
In the simplest sense, hearing aids consist of two microphones, an amplifier, and a receiver. But that description doesn’t quite do them justice. Hearing aids are innovative pieces of technology – mini sound computers in effect – that allow people with hearing loss to hear clearly. A lot of work goes into creating a device that not only lets people hear but lets them experience sound in a natural, enjoyable way.
We created a two-minute video to show you the how the different parts combine to form Signia hearing aids:
An inside look at hearing aids
To understand the complexities of hearing aids, you have to take a look inside and examine each component. Similar to your actual ears, hearing aids are full of individual parts that work together in tandem to help you hear. Since you wouldn’t want to take apart your own hearing aids, we’ll walk you through each piece and what they do.
What does the inside of a hearing aid look like?
Underneath the casing and screws, a hearing aid is made up of several layers. These layers contain its inner workings, which consist of microphones and other high-tech parts. Below is a list of each of these parts and how they work to help you hear.
• Microphones. Like typical microphones, these pick up sounds and transform them into electrical signals that the processor can understand. Unlike the microphones used on stage or the smaller ones found in headphones, these microphones are extremely small and highly precise. They need to pick up sound as clearly as possible, so they’re very advanced.
• Processor. This is the most important and varied part of your hearing aid. It handles the bulk of the work, transforming these signals and changing them according to your specifications. A hearing processor is a tiny supercomputer, and its sole purpose is creating sound. The quality of this processor determines the features and functionality of your hearing aid, so state-of-the-art hearing aids are equipped with refined, specialized processors.
• Cable. This is the small, hollow tube that contains the wiring of your hearing aid. It feeds into your ear and transmits sound along the wires to the receiver in your ear.
• Receiver. Once the electrical signals have traveled down the cable, the receiver transforms them back into sound. Then, it plays the processed sound into your ears so you can hear it.
• Battery. Obviously, this powers your hearing aid. Most hearing aids use disposable zinc-ion batteries, but many high-end hearing aids feature rechargeable lithium-ion batteries.
• Casing. This is the shell that protects your hearing aids. It’s usually made of plastic and can come in a variety of colors and designs. Many hearing aids come with a casing that’s treated with a water-repellent coating, which helps them resist water damage from rain or sweat. The casing of your hearing aid has places for buttons and, in the case of zinc-ion batteries, battery removal.
How do we hear?
Now that we know what’s inside hearing aids, we can move on to how our hearing works.
For people with healthy hearing, sound is funneled down the ear canal and eventually reaches the cochlea, where it’s processed and sent to the brain. However, hearing loss can hinder the process and make it difficult to hear. Only some sounds might make it to the brain, or none at all. The most common form of hearing loss is sensorineural hearing loss, where the cochlea is the broken link.
Hearing aids bridge that broken link and allow sound to travel up the chain to the brain. There might be some differences to how things sound, but most people adjust to their new way of hearing after a short time. Hearing aid manufacturers are always looking for ways to improve this process and achieve a more natural, enjoyable sound.
In the end, hearing aids are a solution to a problem people have been having for centuries. When our ears begin to fail, technology can pick up the slack and allow us to hear properly. As this technology evolves, hearing aids become more functional and aesthetically pleasing. In fact, the appearance of hearing aids plays a large part in how they work.
Inside vs. outside
Many hearing aids share a similar appearance. This leads many people to ask, “why do hearing aids look the way they do?”
The answer lies in hearing aid design. By arranging the internal components in a certain way, the shape of the hearing aid contributes to how the user wears it. During previous generations, hearing aids were clunky and hard to wear, which led many people to decline offers to be fitted. The challenge was to arrange the components so they work in harmony without interfering with each other. Hearing aids needed to be compact to work properly and still fit on the wearer’s ear. On the other hand, the housing has to have an ergonomic shape so it is as comfortable and discreet as possible.
So, many modern hearing aids that are worn behind the ears are designed with a certain shape. This shape allows all of the necessary components to fit inside, while still curving comfortably behind the ear. Most of these models have similar or identical shapes, but times are changing. For example, one model is taking a new approach to hearing aid design. The Signia Styletto Connect has an entirely new shape and looks more like elegant wearable technology than a hearing aid.
There’s also the existence of other types of hearing aids, like those worn in the ear. These look different as well, though functionality varies across these models. Regardless of what kind of hearing aid you have, it’s specifically designed to be comfortable and inconspicuous, while still offering the best hearing experience possible.
How do hearing aids work?
Depending on the level of hearing loss, the details might change. However, the basic idea of hearing aids remains the same. The microphone picks up the sound, the processor converts it, and the receiver plays it back to the wearer. The hearing aid can be equipped with additional software for extra features, including Signia’s unique Own Voice Processing (OVP™) or direct streaming via Bluetooth®.
As sounds are made, the soundwaves travel through the air. When they reach your hearing aid, a microphone picks them up. Once sound is converted by the microphone, the hard work begins.
The processor inside the hearing aid, which is much smaller than anything you’d find in a smartphone or laptop, begins to translate the sound. With settings and software, noises are tailored to your specifications. Your audiologist will help you program your hearing aid so you get the most comfortable, enjoyable sound quality. This can vary in tone and volume, and certain features like OVP and feedback cancellation can play a part in the process. Wind noise and background voices can be filtered out, and your own voice can be processed in real-time, so you hear yourself naturally.
From there, the sound is conducted through an electrical cable to the receiver, which is put in your ear canal. A proper fit will ensure that the hearing aid stays in place and performs properly.
State-of-the-art hearing aids also work in a way that we cannot observe. When two hearing aids are in use, they communicate with each other to sync together and exchange data. This ensures that the user is getting a realistic, bilateral sound. Many Signia hearing aids can even connect via Bluetooth to offer direct streaming and remote control.
While this is a simplified explanation of how hearing aids work, you can learn more through personal research. If you have questions, try searching for information on your hearing aid’s specific model, or ask an audiologist. Knowing how your hearing aid works can give you valuable insight into how it helps you. It’s also important to remember that technology is always evolving. Signia is devoted to constant advancement, and who knows what improvements lie in the near future?
If you gained something from this article, you might be interested in learning more. Signia has an entire library of articles dedicated to how we hear, hearing loss, ear health, and hearing aids. If that’s not enough, we also update regularly with new information. Subscribe to our newsletter to stay informed.