What, Why, How, Where and When
What is a hearing aid?
A hearing aid is a small electronic device that you wear in or behind your ear. It amplifies sounds so that a person with hearing loss can listen, communicate, and participate more fully in daily activities. A hearing aid can help people hear better in both quiet and noisy situations. However, its surprising that only about one out of five people with hearing loss use hearing aids.
A hearing aid has three basic parts: a microphone, amplifier, and speaker. The hearing aid receives sounds 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 or a receiver.
How can hearing aids help?
Hearing aids are primarily useful in improving the hearing sensitivity and speech comprehension of individuals who have hearing loss resulting from damage to the 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, ageing, hereditary, injury from loud noises (also called noise induced hearing loss-NIHL) or from certain ototoxic medicines.
A hearing aid amplifies 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. In these cases a Cochlear Implant can be beneficial provided the inner ear is intact anatomically.
How can I find out if I need a hearing aid?
If you think you might have hearing loss and could benefit from a hearing aid, visit your audiologist. An audiologist is a hearing health professional (hearing doctor) who identifies and measures hearing loss and performs a detailed hearing test to assess the type and degree of loss and prescribes appropriate type of hearing aid that suits the individual’s hearing loss and lifestyle.
Are there different types of hearing aids?
- Yes, there are various types of hearing aids available as shown in the picture above. It is imperative to note that each type or style of hearing aid is meant to be worn by individuals with a certain type and degree of hearing loss (see the explanation below for details).
- Behind-The-Ear (BTE) hearing aids consist of a hard plastic case worn behind the ear and connected to an acrylic (hard) or silicone (soft) earmold that fits inside the outer ear or pinna. The electronic parts are held in the hard plastic fiber case behind the ear. Sound travels from the hearing aid through the earmold and into the ear. BTE aids are used by people across all ages with mild to profound degree of hearing loss.
- Receiver-In-The-Canal (RIC) aid is an open-fit hearing aid. Small hearing aids that sit behind the ear completely, with only a thin wire inserted into the ear canal, enabling the canal to remain open. For this reason, open-fit hearing aids may be a good choice for people who experience a buildup of earwax, since this type of aid is less likely to be damaged by such substances. In addition, some people may prefer the open-fit hearing aid because their perception of their voice does not sound “plugged up.” These RIC aids can also be used with various degree of hearing loss with appropriate acoustic modifications prescribed by your Audiologist. This type of hearing aid is a good choice of style for individuals who are cosmetically aware.
- In-The-Ear (ITE) or In-The-Canal (ITC) hearing aids fit completely inside the outer ear (pinna and ear canal) and are used for mild to severe hearing loss. The case holding the electronic components is made of hard plastic. Some ITE/ITC aids may have certain added features installed, such as a telecoil. A telecoil is a small magnetic coil that allows users to receive sound through the circuitry of the hearing aid, rather than through its microphone. This makes it easier to hear conversations over the telephone. A telecoil also helps people hear in public facilities that have installed special sound systems, called induction loop systems. Induction loop systems can be found in many theatres, schools, airports, and auditoriums. ITE/ITC aids usually are not worn by young children because the casings need to be replaced often as the ear grows.
- Completely-In-Canal (CIC) hearing aid is nearly hidden in the ear canal. Both types are used for mild to moderately severe hearing loss. Because they are small, CIC aids may be difficult for a person with dexterity issues to adjust and remove the aids. In addition, CIC aids have less space available for batteries and additional devices, such as a telecoil. They usually are not recommended for young children or for people with severe to profound hearing loss because their reduced size limits their power, volume and battery backup.
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 aids are also called trimmer controlled hearing aids that come with pre-programmed settings (usually 3 settings) by the manufacturer. An audiologist can set the aid using a device or through an app provided by the manufacturer, and you can manually change the programs for different listening environments—from a small, quiet room to a large crowded restaurant. Analog aids usually are less expensive than digital aids and does not provide good sound quality and clarity of speech (in noisy places) when compared to digital programmable hearing aids.
Digital aids convert sound waves into numerical codes, similar to the binary code of a computer and modifies and amplifies them through complicated digital signal processing (DSP) unit called central processing unit (CPU). Because the code also includes information about a sound’s pitch (frequency) or loudness (intensity), the aid can be specifically programmed to amplify or modify certain frequencies more than others. Digital circuitry gives an audiologist more flexibility in adjusting the aid and helps in tailor-making the program to suit the individual’s hearing loss and user’s needs in 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. These are the best type of hearing aids for individuals with a busy and vibrant lifestyles and whose communication needs are high.
Which hearing aid will work best for me?
The hearing aid that will work best for you depends on the type and severity of your hearing loss. If you have a hearing loss in both 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, even in noisy and challenging listening situations.
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 few thousands (usually 15,000 rs) to several lakh rupees (1 to 3 lakh rupees). Similar to other equipment purchases, style and features affect cost. Note that a hearing aid will not restore your normal hearing sensitivity. With practice, however, a hearing aid will increase your awareness of sounds and neural connectivity and functioning of the hearing nerve (auditory nerve).
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 costs for maintenance and repair, options and upgrade opportunities, and the hearing aid company’s reputation for quality and customer service.
How can I adjust to my hearing aid?
Hearing aids take time and patience to use successfully. Wearing your aids regularly will help you adjust to them.
Become familiar with your hearing aid’s features. With your audiologist present, practice putting in and taking out the aid, cleaning it, identifying right and left aids, and replacing the batteries. Learn to adjust the aid’s volume and to program it for sounds that are too loud or too soft. Work with your audiologist until you are comfortable and satisfied.
You may experience some of the following problems as you adjust to wearing your new aid.
- My hearing aid feels uncomfortable. Some individuals may find a hearing aid to be slightly uncomfortable at first. Ask your audiologist how long you should wear your hearing aid while you are adjusting to it.
- My voice sounds too loud. The “plugged-up” sensation that causes a hearing aid user’s voice to sound louder inside the head is called the occlusion effect, and it is very common for new hearing aid users. Check with your audiologist to see if a correction is possible. Most individuals get used to this effect over time.
- I get feedback from my hearing aid. A whistling sound can be caused by a hearing aid that does not fit or work well or is clogged by earwax or fluid. See your audiologist for adjustments.
- I hear background noise. A hearing aid does not completely separate the sounds you want to hear from the ones you do not want to hear. Sometimes, however, the hearing aid may need to be adjusted. Talk with your audiologist.
- I hear a buzzing sound when I use my cell phone. Some people who wear hearing aids or have implanted hearing devices experience problems with the radio frequency interference caused by digital cell phones. Both hearing aids and cell phones are improving, so these problems are occurring less often these days. When you are being fitted for a new hearing aid, take your cell phone with you to see if it will work well with the aid.
How can I care for my hearing aid?
Proper maintenance and care will extend the life of your hearing aid. Make it a habit to:
- Keep hearing aids away from heat and moisture.
- Clean hearing aids as instructed. Earwax and ear drainage can damage a hearing aid.
- Avoid using hairspray or other hair care products while wearing hearing aids.
- Turn off hearing aids when they are not in use.
- Replace dead batteries immediately.
- Keep replacement batteries and small aids away from children and pets.
Are implantable hearing aids available?
- Yes, implantable hearing aids such as Middle ear implant (MEI) and Bone anchored hearing aids (BAHA) are available. Although, they work differently than the traditional hearing aids described above, implantable hearing aids are designed to help increase the transmission of sound vibrations entering the inner ear. A middle ear implant (MEI) is a small device attached to one of the bones of the middle ear. Rather than amplifying the sound traveling to the eardrum, a MEI moves these bones directly. Both techniques have the net result of strengthening sound vibrations entering the inner ear so that they can be detected by individuals with sensorineural hearing loss.
- A bone-anchored hearing aid (BAHA) is a small device that attaches to the bone behind the ear. The device transmits sound vibrations directly to the inner ear through the skull, bypassing the middle ear. BAHAs are generally used by individuals with middle ear problems or deafness in one ear (also called SSD-single sided deafness). Because surgery is required to implant either of these devices, many hearing specialists feel that the benefits may not outweigh the risks.
Note that hearing aids are “Medical Devices” and not just another electronic device. Individuals with hearing loss should wear the right kind of hearing aids prescribed by a qualified audiologist (after undergoing a detailed hearing assessment). Wearing the wrong kind of hearing aids can result in “Tinnitus”, “Headaches”, “Ear Pain”, “Soreness”, “Auditory Fatigue”, “Tolerance Issues” and can damage the auditory nerve permanently.