How Do Hearing Aids Work?
Over the last few years, hearing aids have become increasingly more sophisticated, primarily because of advances in the smartphone market. Their primary function, however, hasn’t changed much since manufacturers introduced them several decades ago.
How hearing aids work: the basics
People with hearing loss often cannot detect all the noises in their sound environment. The purpose of a hearing aid, therefore, is to amplify these sounds to boost the signal the inner ear sends to the brain.
Hearing aids rely on three critical components to do their job: the microphone, the processor and the speaker.
The microphone typically sits on the outward-facing part of the device. Positioning it in this way allows it to collect incoming sound waves. On behind-the-ear (BTE) devices, the receiver sits on the section that loops around the back of the ear. For in-the-ear (ITE) and some canal varieties, the microphone sits on the exterior-facing part.
How they work
As sound waves travel to the device, the microphone converts them into an electrical to send to the central processing unit. While hearing aid processing units perform a lot of functions, their primary task is to prepare a modified signal for the speaker. This modification enhances the quality of the incoming sound in a way that compensates for the patient’s hearing loss characteristics. The processor then emits a new signal to the speaker. The speaker takes this signal and creates an enhanced version of the sounds in the external environment. Typically, this enhancement takes the form of amplification, but not always.
The speaker sits on the section of the hearing aid facing the eardrum. The purpose of this is to ensure that the wearer receives the maximum sound fidelity.
Hearing aids, however, have an inherent problem that makes designing them difficult. Due to their small size, the microphone and the speaker often sit close to each other. Thus, there’s a risk that the microphone will pick up sounds emitted by the speaker, causing a feedback loop.
Manufacturers, therefore, have developed sophisticated systems to detect this problem and cut it out before it causes the wearer concern. These failsafes were important on the first BTE devices. But they’ve become even more critical in recent years as more hearing aid users choose in-ear varieties which house all components close together.
While amplification is the primary task of hearing aids, they also assist people who are hard of hearing in other essential ways.
Take those who need help with directional hearing, for instance. Often people with hearing loss can find it hard to focus on a single voice in a loud room. They can also find it challenging to determine the direction of incoming sounds.
Hearing aid manufacturers, therefore, have adapted their technology to provide performance enhancements that accommodate these problems. Directional microphones, for example, can make it easier for those who are hard of hearing to hold a conversation in a noisy room.
The profile of hearing loss also tends to vary from one person to another. Some people find it easy to hear low-frequency sounds but struggle to pick up on higher frequency noises. Manufacturers, therefore, equip their devices with “channels.” This feature allows you to customize the level of application across the frequency range. So, if your hearing loss is mainly at the lower end of the sound distribution, you can tweak the amplification profile to increase the volume of these while leaving high-pitch noises untouched.
Modern hearing aids, however, go way beyond their historical function. Today’s devices are more like miniature computers that you wear in your ears than the simple earpieces of old. Many of them come with advanced features that radically transform the user experience and provide numerous quality of life improvements.
For instance, many modern hearing aids now double as wireless Bluetooth headphones. All you do is connect them to your smartphone or notebook and then stream music directly to the speaker via a Bluetooth signal, bypassing the microphone entirely.
Many devices now also can automatically adjust settings on the fly. Hearing aid requirements change throughout the day. Sometimes you’re outside and require general amplification to pick up on birdsong or approaching vehicles. Other times, you’re in noisy meetings or bars and need settings that allow you to block out extraneous sounds and focus on the person in front of you. Recent models frequently offer onboard software that detects the sound environment and then automatically changes settings, without you having to fiddle with them manually.
So, do you think you or somebody you know may need hearing aids? If so, get in touch with Your Hearing Connection at 626-538-9920 today.