How Hearing Aids Work

For those with hearing loss, life can become a series of struggles. Friends and family members may become tired of shouting, while others resort to avoiding communication altogether. Many individuals with hearing loss actively avoid social interactions because they feel lost in conversation. These problems often result in feelings of loneliness and isolation, resulting in a lower quality of living. Fortunately for those with permanent hearing loss, hearing aids can help restore hearing and improve the quality of life.

Hearing aids are fairly simple, small electronic devices that are placed in, on, or around the ear(s) that amplify sound. Hearing aids increase the volume of certain sounds (such as voices) so individuals can better listen, communicate, and participate more fully in daily activities.

Let’s explore how these devices work in more detail.

Analog vs. Digital hearing aids

Analog hearing aids merely amplify all sounds equally and transmit the amplified sounds to your ears. This means that unwanted sounds – including the sounds of the dishwasher or the television in the other room – may drown out wanted sounds, such as the person who is talking right in front of you. Most analog hearing aids can be adjusted to amplify certain sounds depending on your condition, but these aids are not as sensitive or nearly as flexible as digital hearing aids. Due to their inflexibility, most analog hearing aids are being phased out by manufacturers.

Most modern hearing aids are digital, which means that the audio information picked up from the microphone is turned into digital information and is processed by a tiny computer before transmitting the sounds to your ears. These hearing aids can often be adjusted through software by audiologists to fit your changing needs. Although most digital hearing aids are more expensive than analog hearing aids, their flexibility and control results in a much clearer sound quality.

Components and signal flow of hearing aids

Electronically speaking, hearing aids are fairly simple devices. Hearing aids consist of four basic parts: a microphone, amplifier, speaker, and a battery. The battery – which is usually replaceable – simply supplies power to the device.

The microphone picks up sound from the environment and turns it into an electrical/digital code that is transmitted to the amplifier and/or processor (depending on whether the hearing aid is analog or digital).

If the hearing aid is digital, the electrical signals are converted into digital information, which is processed by the device’s internal chip. The computer chip analyzes the sound according to the individuals hearing loss and listening situation. After processing, the digital information is converted back into electrical signals which are sent to the amplifier. If the hearing aid is analog, the electrical signals from the microphone are sent straight to the amplifier.

The amplifier collects the sound information from the microphone/processor and amplifies the electrical signals, which are then sent to the speaker. Finally, the speaker converts the electrical signal back into sound and the sound waves are transmitted into the ear.