What Are Hearing Aids Made Of?

Hearing aids are tiny digital electronic devices that help people to hear. They process, analyze, and amplify sound in real time. Hearing aids work under more adverse conditions than most high-tech devices. They run for 16 hours a day in ears that are hot, humid, oily and waxy. They are exposed to freezing temperatures in the winter and high heat and humidity in the summer. They must be resistant to rain, snow, perspiration, dust and dirt. So what's inside those tiny pieces of plastic that help people to hear?

Microphone and Speaker

The microphone is a transducer that converts sound into an electrical signal. Some microphones are designed to pick up sound from all directions (omnidirectional) or from certain directions (directional). Some hearing aids use two microphones, one front-facing and the other rear-facing. This enables the processor to determine which sounds come from behind the listener and which come from the front. The speaker converts the processed and amplified electrical signals into sound, which is sent into your ear. The speaker is usually housed in the casing of a hearing aid. However, some hearing aids have the speaker placed in your ear canal. Some use a tube that connects the speaker to a plug or custom-molded piece.

Processor and Amplifier

The microprocessor digitizes sound then analyzes it, using algorithms designed to detect the characteristics of speech and the characteristics background noise. Both are processed to improve the clarity of speech and to reduce the loudness of background noise. The amplifier boosts the frequencies that you do not hear, so that speech and everyday sounds become audible.

Battery Compartment

The battery compartment holds the battery, which supplies the electricity to power the hearing aid. The battery compartment is easy to access and is used to turn the hearing aid on and off.

On-board Controls and Remote Controls

Digital hearing aids are designed to run automatically, but some have controls on the hearing aids so you can manually adjust the volume and choose from preset programs. The programs are set by your hearing care provider to process sound for different listening situations, such as music appreciation or high levels of background noise. Some hearing aids have an optional remote control to adjust volume and select preset programs. Some provide an additional control to manually adjust the amount of clarity and comfort in different environments. Others allow you to focus to the front, sides and behind.

Binaural Communication

Most hearing aids work independently of each other. So, when you change the volume or program on one hearing aid, you have to change it on the other one. Hearing aids with binaural communication work as a pair so that both hearing aids adjust volume and programs together.

Datalogging

Datalogging is a tool that hearing care professionals use for counseling and to fine-tune the settings of your hearing aids. This feature keeps track of the number of hours you use the hearing aids per day. It keeps track of the different listening environments you're in, such as speech in quiet, speech in noise, noise-only and music. It also indicates the type of sound processing the hearing aid used in each environment. Datalogging keeps track of how often you use the volume control, the changes you make, and which listening environments you make those changes. It keeps track of the programs you use and how long you use each program.

Bluetooth

Some hearing aids use Bluetooth technology for wireless connection to Bluetooth devices, such as phones, GPS navigation systems and music players. The hearing aids require an accessory that receives the Bluetooth signal and wirelessly transmits it to the hearing aids.