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How do Hearing Aids Work

Topic: How do Hearing Aids Work

Most people consider the eye as the most important sense organ in the body. Well, the ear is also important because it allows us to hear information and receive alerts when confronted with danger even when we cannot see. For instance, if you are blind, you may not see a car coming from your back or front, but you can hear the horn or sound of the car. When we interact with one another, we speak and listen to make communication effective. We also listen to music to experience deep emotions.
However, how isolating and frightening it can be if you have issues with hearing. It is even worse for those who haven’t heard a single sound right from birth. For those with hearing ability, over time, their ability to hear deteriorates, as they get older. Luckily, through technology, people suffering from hearing loss can resolve the issue. In this article, we will look at what hearing aids are, how they work, and what a hearing aid can solve.

What is a Hearing aid?

A hearing aid is an electronic device used to improve the hearing condition of someone suffering from hearing loss. It is quite small to fit behind or in your ear. Furthermore, the device enables the individual to hear sound loudly. Hearing loss can influence your life in general. It can affect your relationship, work, family, and eventually your emotional well-being. Notwithstanding, hearing aids can be the missing link especially if you buy the right one.
A hearing aid comprises of three key components, which includes:

  • Microphone – Picks the sound around your environment
  • Amplifier – Increase the sound
  • Receiver – transmit the amplified sounds to the ear

Note: Not everyone will benefit in using hearing aids because they don’t solve all hearing loss condition. However, 1 out of 5 people may experience an improvement after using them. Generally, hearing aids are suitable for individuals with injury to their inner ear or have damage the nerve that connects their ear to the brain. Such damage could be the product of

  • Loud noises
  • Aging
  • Disease
  • Medications

How the ear receives Sound Energy

What we hear as sounds is a form of energy. When things vibrate, they generate sound. For instance, when you bang a drum, the tense drum skin vibrates very rapidly. This pushes and pulls the air molecules close to it.  Furthermore, the air molecules move dynamically against each other before crashing into other molecules. This is how waves of sound energy proceed from the drum to all directions. This energy then travels through the air before it gets to the ears.
The shape of the big outer flaps (pinnae) of the ears is designed in such a way that it can collect sounds from different directions. The pinnae then funnel these sounds into the ear canal. The ear canal is the hole that goes directly into the inner ear. The eardrum (a tiny drum-like skin) is located at the end of the ear canal vibrates whenever an inbound sound waves hit it. The skull has three tiny bones – stapes, anvil, and hammer, which detect the eardrum vibrations before transferring them to the cochlea.
The cochlea contains tiny hairs and fluid known as cilia. The vibration causes the fluid to move in a backward and forward direction before beating the cilia. Once the cilia detect these vibrations, it sends electrical signals to the brain, which results in the sound you hear. In general, hearing involves sound energy, which is converted in the ear into electrical impulses by the cilia within the cochlea.

How People lose their hearing

People can lose or become deaf for various reasons. This loss can be due to the blockage between the brain and the outer ear. However, one of the prevalent types of hearing loss that affects most people is when the tiny hairs in the cochlea are damaged or blocked. When a person needs louder sound for him or her to hear properly, then there are fewer hairs in the cochlea. Hence, sounds generate less vibration in the brain. In this situation, a hearing aid is inevitable to make the sound louder. Hearing aids cannot help everyone with hearing problem but can make a huge difference if the problem is due to the loss of cochlear hair cells. Another name for this condition is sensorineural hearing loss.

How Hearing Aids Work

Have you ever seen someone yelled at a deaf person’s ear? What happens is that they transmit sound waves with greater energy and amplitude (volume) to the person’s ear canal. The tiny hair cells will probably identify these energetic sound waves, which subsequently make it easier for them to hear the individual yelling.
Old-fashioned ear trumpets work in a different way. Actually, the outer ear is bigger and focuses the energy of the incoming sounds into smaller areas. This escalates the pressure of the sound generated on the eardrum and further increases the probabilities of the person’s hearing ability.
Although using ear trumpets and shouting louder is simpler when considering using a mechanical solution to hearing loss problem, however, a hearing aid is a more complex electrical solution to solve a hearing loss problem. A hearing aid is merely an electronic sound amplifier. Perhaps, you may have seen people use microphone on a stage. Their voice is highly amplified by those big loudspeakers, which enable the crowd to hear them from wherever they are sitting. A hearing aid works in same manner, besides the fact that the loudspeaker, amplifier, and microphone are packed into a little, unnoticeable plastic package. This is worn either inside the ear canal or behind the ear depending on the choice of the user.
There are four styles of hearing aid but the most common is the behind the ear (BTE) hearing aid, which comprises of two separate pieces. It has a hard plastic case, which contains a loudspeaker, amplifier, and a small microphone. These items are connected through a tube directly to a softer plug, which has an ear mold shape to perfectly fit into the ear canal of the individual. In this type of hearing aid, the microphone picks the sound within the environment and converts them into electrical current. Furthermore, the amplifier, which consists of transistors, increases electric current size whereas the loudspeaker transforms the increased current into a louder sound. Eventually, the amplified sound moves via the tube to the earmold and finally to the person’s ear.
The other type of hearing aid is the completely in the canal (CIC) hearing aid, which contains all the components as the previous one. However, it is fitted via a small plug, which goes directly to the ear canal. There is also the in the canal (ITC) hearing aid, which is a larger hearing aid and is partially within the canal and outer ear. The last type of hearing aid is the in the ear (ITE) hearing aid that fills the canal with the other part partially on the outer ear. Nowadays, hearing aids such as ITE, ITC, and CIC is very unnoticeable unless you stand closer to the person wearing it.

Kinds of Hearing Aids

Hearing aids are of two kinds – analog and digital hearing aids. The job of the analog hearing aid is to convert sound waves into electrical currents. It then boosts the electrical currents and converts them into louder sound. However, digital hearing aids work differently, more complicated and expensive. They convert sound waves into a numerical coded signal, then process and enhance these signals before converting them into sound. Unlike analog hearing aids, they can be tuned to block unwanted noise. On the other hand, analog hearing aids amplify everything within the environment without blocking unwanted noise.
In as much as a hearing aid lack the capability of restoring the hearing loss problem of an individual, it does make a big difference. Through hearing aids, the individual enjoys a normal life like listening to radio, TV, hear recorded music or even hear the birds sing. This is merely a wonderful example of how science can influence and improve our lives.

How does Analog Hearing Aid Works

Sound waves move toward the ear and the hearing aid. The hearing aid has a small microphone, which picks the sound and converts them into electrical current. Furthermore, the amplifier in the device intensifies the current strength, which then pushes it to the small loudspeaker. The device contains a battery, which powers the various components. However, the loudspeaker plays the amplified sound via the ear mold then to the ear canal. Finally, the sound waves then move directly into the inner ear due to its increased volume.

How does Digital Hearing Aid Works

Digital hearing aids use a mixture of different methods, which is generally recognized as digital signal processing (DSP). These methods include:

  • Compression: This is an important feature of a digital hearing aid in as much as it seems to be complex. In spite of this, the idea behind it is simple. Someone without any hearing impairment can hear sounds at a full range; however, a person with hearing impairment won’t hear a sound like a person without any impairment. In this situation, the person’s will only hear sound from a shorter frequency range. The function of a hearing aid is to compress or squeeze the range of soft and loud sounds into smaller range in order for the individual to hear well.
  • Gain adjustment: A gain is an extent through which an amplifier increases a sound frequency (or frequencies). You can selectively adjust the gain setting of digital hearing aid to match the person’s hearing loss problem. You can liken gain adjustment to be like the graphic equalizer on a mixer or a stereo where you can adjust the bass, treble, or speech of a particular instrument.
  • Speech boosting: This selectively enhances sound frequencies within the range of 100 to 1000Hz.
  • Sound classification: This groups the sounds you hear into noise, speech, or music and reduces or amplifies them selectively. However, certain complex hearing aids can effectively find out the particular environment you are such lecture theater, noisy restaurant, concert hall, distant speaker, etc. additionally, they use a different strengthening pattern for the sound you hear. Although they work like complex programmable analog hearing aids, however, they switch automatically to decide the current environment.
  • Feedback reduction: People using hearing aids suffer from two types of feedback, which are mechanical and acoustic. Sounds electrically amplified suffer acoustic feedback.

Which is better – Analog or Digital Hearing Aids?

Considering the fact that digital hearing aids are twice the cost of analog aids, are they worth the cost? That is evidently a subjective question. For most people, the small nature of the completely in the canal hearing aid is a better choice. It doesn’t matter if it is a digital or analog hearing aid. However, another option that offers a better performance is behind the ear hearing aid. It is hard to determine if a digital or analog hearing aid will produce better result unless you have tried it and see.
Notwithstanding, before considering if an analog or digital hearing aid will be better for your situation, you have to perform a medical examination. Additionally, after an audiologist has evaluated your hearing problem, he will refer you to an otolaryngologist to purchase the hearing aid. An otolaryngologist focuses on disorders of the nose, ear, neck, throat, and head.

What does a hearing aid solve?

An evolving question most people ask is if a hearing aid is a device that amplifies sound and comprises of few transistors, why is it expensive? Obviously, it is not as simple as you thought. Well, there isn’t a specific type of hearing loss. There are three reasons why people can lose hearing. At times, it could be a combination of these three and they are:

  • Conductive hearing loss: In this, the sound does not travel properly to the inner ear from outside. This condition can be corrected through simple amplification or surgery.
  • Sensorineural Hearing Loss: This had to do with a problem in the cochlea, where the cilia lack the capacity to detect certain frequencies of sounds as it was supposed to detect. Most hearing loss problem falls within this category, which is what many are seeking to address using hearing aids.
  • Neural Impairment: A minor problem in your brain can affect one’s ability to interpret sound signals even after the ears have collected those sounds. Possible causes of this situation could be a brain injury, stroke, or a brain tumor. However, it is not a common problem as the sensorineural hearing loss problem and a hearing aid cannot address the issue.

Another issue to address is how hearing aids address these problems. Theoretically, an analog hearing aid is very simple to address this problem. Actually, if hearing aids device were just a small loudspeaker and microphone, then it would magnify all sounds using an equal amount. Most people with hearing impairment doesn’t want this. When an audiologist performs a hearing test, he or she creates the precise pattern of frequencies that the individual can or cannot hear. This pattern is known as an audiogram.
Note: There is no natural remedy to remedy your hearing loss problem because the tiny hair cells in the inner ear are responsible for converting sounds from the environment into electrical impulses. These impulses are then interpreted by the brain. Knowing this, you should take necessary steps to avoid anything that will cause hearing impairment such as listening to sound louder than 85 decibels.

Adjusting Hearing Aids

Hearing aids are not meant to restore your hearing ability but to make you more aware of sounds within your environment. For those using it for the first time, you have to be patient. However, there is always a trial period for you to test the hearing aid before you decide to buy it.
Furthermore, be patient to know how the aid work and look for one that perfectly fits your ear. Ensure to work closely with a professional audiologist in order to avoid issues such as:

  • Background noise
  • Whistling or feedback sound
  • Buzzing when using a cell phone
  • Echo sounds from your voice
  • Discomfort

Importantly, the lifespan of your hearing aid depends on how you take care of it. Ensure to adhere to the following tips:

  • Immediately replace the dead battery
  • Turn off when not in use
  • Keep away from moisture, heat, pets, children, and hair care products
  • Clean as directed

Conclusion

Hearing loss is a complicated disability for anyone to experience because it influences the quality of one’s life. Hearing loss should not restrict you from performing your daily activities. Undoubtedly, hearing aids are the perfect technological solution to hearing impairment. However, having a good and productive hearing aid is expensive such that only the rich can afford. In spite of this, there are still affordable hearing aids for people to use to alleviate their hearing impairment. Hearing aids are meant to improve your hearing impairment and make sounds more audible. They are important device that everyone with hearing impairment must use.