How Do Hearing Aids Work?
To put it simply: Hearing aids supplement our hearing. But how exactly do they work? Firstly, hearing aids are designed to receive sounds from the outside world, just like a healthy ear would do. To do so, they include microphones as part of the design, which take sounds and convert them into vibrations, and then into electrical impulses.
However, at this stage these signals are often too weak, and need to be amplified before they can be converted into something wearers can actually hear. Amplifiers inside the hearing aid casing do the job, turning even very quiet noises into signals that can be turned into audible noise.
The final part of the hearing aid is (usually) the speaker, which takes these amplified signals and produces noise. The precise sound level can almost always be finely calibrated, depending on the environment and the wearer’s degree of deafness. Many hearing aids can also be calibrated to amplify high or low frequency sounds, again, depending on the user’s needs.
What is a hearing aid?
A hearing aid is a small electronic device that you wear in or behind your ear. It makes some sounds louder so that a person with hearing loss can listen, communicate, and participate more fully in daily activities. A hearing aid can help people hear more in both quiet and noisy situations. However, only about one out of five people who would benefit from a hearing aid actually uses one.
A hearing aid has three basic parts: a microphone, amplifier, and speaker. The hearing aid receives sound through a microphone, which converts the sound waves to electrical signals and sends them to an amplifier. The amplifier increases the power of the signals and then sends them to the ear through a speaker.
How can hearing aids help?
Hearing aids are primarily useful in improving the hearing and speech comprehension of people who have hearing loss that results from damage to the small sensory cells in the inner ear, called hair cells. This type of hearing loss is called sensorineural hearing loss. The damage can occur as a result of disease, aging, or injury from noise or certain medicines.
A hearing aid magnifies sound vibrations entering the ear. Surviving hair cells detect the larger vibrations and convert them into neural signals that are passed along to the brain. The greater the damage to a person’s hair cells, the more severe the hearing loss, and the greater the hearing aid amplification needed to make up the difference. However, there are practical limits to the amount of amplification a hearing aid can provide. In addition, if the inner ear is too damaged, even large vibrations will not be converted into neural signals. In this situation, a hearing aid would be ineffective.
Do all hearing aids work the same way?
Hearing aids work differently depending on the electronics used. The two main types of electronics are analog and digital.
Analog aids convert sound waves into electrical signals, which are amplified. Analog/adjustable hearing aids are custom built to meet the needs of each user. The aid is programmed by the manufacturer according to the specifications recommended by your audiologist. Analog/programmable hearing aids have more than one program or setting. An audiologist can program the aid using a computer, and you can change the program for different listening environments—from a small, quiet room to a crowded restaurant to large, open areas, such as a theater or stadium. Analog/programmable circuitry can be used in all types of hearing aids. Analog aids usually are less expensive than digital aids.
Digital aids convert sound waves into numerical codes, similar to the binary code of a computer, before amplifying them. Because the code also includes information about a sound’s pitch or loudness, the aid can be specially programmed to amplify some frequencies more than others. Digital circuitry gives an audiologist more flexibility in adjusting the aid to a user’s needs and to certain listening environments. These aids also can be programmed to focus on sounds coming from a specific direction. Digital circuitry can be used in all types of hearing aids.
Which hearing aid will work best for me?
The hearing aid that will work best for you depends on the kind and severity of your hearing loss. If you have a hearing loss in both of your ears, two hearing aids are generally recommended because two aids provide a more natural signal to the brain. Hearing in both ears also will help you understand speech and locate where the sound is coming from.
You and your audiologist should select a hearing aid that best suits your needs and lifestyle. Price is also a key consideration because hearing aids range from hundreds to several thousand dollars. Similar to other equipment purchases, style and features affect cost. However, don’t use price alone to determine the best hearing aid for you. Just because one hearing aid is more expensive than another does not necessarily mean that it will better suit your needs.
A hearing aid will not restore your normal hearing. With practice, however, a hearing aid will increase your awareness of sounds and their sources. You will want to wear your hearing aid regularly, so select one that is convenient and easy for you to use. Other features to consider include parts or services covered by the warranty, estimated schedule and costs for maintenance and repair, options and upgrade opportunities, and the hearing aid company’s reputation for quality and customer service.
Hearing aids are tiny in size but mighty in sound – but where does all that sound come from? Beyond their shiny shells, hearing aids have tiny computers working tirelessly to give you the best sound possible.We also want a Rechargeable hearing aid machine. Making up this electronic hearing wonder are 5 key components. Here’s how they work.
Rechargeable hearing aid
Main Parts of a Hearing Aid
It all starts with a microphone. The Rechargeable hearing aid microphone picks up incoming sound and sends it to an amplifier, which processes the sound by turning it from an analog signal into a digital signal. This is then sent to the receiver which delivers the sound to your ear in a way that is most true-to-life.
More on these 5 hearing aid parts:
- MICROPHONE: The microphone helps the hearing aid to pick up sounds from outside the ear. There are different types of microphones, both omnidirectional (sensitive to sound from all directions) and directional (sensitive to sound from specific directions).
- AMPLIFIER: The amplifier processes and strengthens the sound signal from the microphone and customizes it according to your individual needs and your hearing loss. It makes the sounds you hear recognizable without being distorted. The amplifier contains most of the hearing aid’s electronic components and circuits in a microchip.
- MICROCHIP: The chip is the nervous system of the hearing aid. Despite its micro size, the chip is incredibly powerful and can handle everything from signal processing to wireless communications. The chip means that Rechargeable hearing aid can be smaller and use less battery power.
- RECEIVER: The receiver or speaker converts the electrical signal into sound and sends it to your ear. How much sound comes out depends on its size. A severe hearing loss will often require a slightly larger hearing aid. Receivers also come with wax guards that help to keep moisture and earwax from entering the hearing aid.
- BATTERY: The engines of the hearing aid, batteries keep the whole thing running. How much power a hearing aid uses varies widely depending on its size, the number of features and the ways in which it is used.
Hearing Aid Features/Rechargeable Hearing Aid Features
Many hearing aids have more than just five main parts. These features can include:
- Telecoil – A telecoil is a small coil inside your hearing aids. The coil works as a small receiver which picks up signals from a loop system that acts as an electromagnetic field. Hearing aids with an activated telecoil can convert this electromagnetic field into a sound signal. Only the signal from the loop system’s microphone is amplified, and background noise is shut out.
- Audibility Extender – The Audibility Extender helps people with high-frequency hearing loss to hear upper-frequency sounds by moving these sounds to a lower frequency region where it is easier to hear them. The upper-frequency sounds are important for hearing the “softer” sounds like /s/ and /t/ in women´s and children´s voices and high-pitched sounds like the “ping” of the microwave.
- Speech Enhancer – The Speech Enhancer is different from simple noise reduction systems in that it doesn´t just dampen noise – it also amplifies speech. When we listen to a sound, we are rarely in doubt as to whether it is speech or noise. The Speech Enhancer in modern hearing aids is able to distinguish the two in much the same way as our brains do – by using the fact that speech consists of a number of varying sound components that follow each other at brief intervals.
- Feedback Cancellation – Feedback Cancellation is a feature that aims to eliminate the whistling and howling caused by a microphone and speaker being too close to one another. With hearing aids, feedback whistling occurs when amplified sound from the ear canal leaks back to the hearing aid microphone. With less modern hearing aids, a whistle or squealing sound from someone’s ear could give a clear sign that they were wearing a hearing aid.
- The compressor – The compressor in a Rechargeable hearing aid is the feature that adjusts gain according to the current sound environment and the client’s hearing loss.
- Wireless communication – At Widex, we have developed our own technology to ensure that your hearing aids can communicate with each other – and with your TV, mobile phone or other devices.