Hearing Aids - Different Types and How They Work

Introduction

Several pathological conditions can cause hearing loss. Some of the conditions can be treated by surgery, depending on the disease. Hearing aids are used primarily for improving the hearing and speech comprehension of people who have hearing loss due to damage to the small sensory cells in the inner ear. However, chronic sensorineural hearing loss due to damaged cochlear structures needs rehabilitation by improving the amplification.

What Is a Hearing Aid?

A hearing aid is a small device used to improve hearing in people with hearing impairment. It fits inside or outside the ear and makes the sound louder. The hearing aid receives sound through a microphone and converts it into electrical waves. These electrical waves are sent to the amplifier, which increases the power of the waves and sends them to the ear through a speaker.

Types of Hearing Aids:

The three types of hearing aids:

1. Behind the Ear- It connects the hearing aid to the earmold.

2. Inside the Ear- It is custom-made, and it is of two types, like a full shell and a half shell.

3. Completely in the Canal - It is less visible and can fit perfectly inside the canal. However, sometimes, the ear wax may clog the speaker.

4. In the Canal - It partly fits inside the canal, and it is customized. It can improve hearing from mild to moderate.

5. Receiver in the Canal - It is similar to the behind-the-ear hearing aid.

6. Open Fit - It is the right choice for people with low-frequency hearing.

Mechanism of Hearing Aid:

There are two mechanisms on which the hearing aid works:

1. Analog: It is less expensive than a digital hearing aid. It converts the sound waves into an electrical signal, amplifies it, and sends it through a speaker to the ear. It is a programmable hearing aid where the settings can be changed on a computer, and one can also change the programs according to the different kinds of environments, like small to big crowds. It can be used in all types of hearing aids. It is an adjustable hearing aid that can be customized according to the needs of the user.

2. Digital: It is quite expensive than an analog hearing aid. It focuses on sound coming from any specific direction, converting the sound waves into a numerical code before amplifying them. The digital circuitry can be adjusted according to the user's needs and listening environment. It can be used in all types of hearing aids.

Parts of the Hearing Aid:

1. Microphones.

2. Mini-chip.

3. Receiver.

4. Battery.

5. Volume control.

Types of Hearing Loss:

• Sensorineural hearing loss is commonly caused by aging, overexposure to noise, viral infection, shingles, diabetes, hypertension, stroke, acoustic tumors, elevated body temperature, or meningitis.

• Conductive hearing loss can be caused due to infection of the ear canal, perforation of the eardrum, wax buildup, abnormal tumor growth in the canal, and foreign bodies in the canal.

• Mixed type.

What Are the Additional Features Added to the Hearing Aids?

Here are some of the key additional features:

• Noise Reduction: Reduces interference and improves the intelligibility of the spoken word. It reduces the chances of wind noises being heard when one is outside the car.

• Directional Microphones: A sound reproduction strategy that concentrates sounds in a particular direction, typically in front of the listener, while attenuating sounds that originate from other directions.

• Bluetooth Connectivity: It pairs with smartphones, tablets, TVs, and other appliances to stream sound straight into hearing aids.

• Telecoil (T-coil): Enables users to record sounds right from compatible telephones and from other public address systems such as those in theaters.

• Rechargeable Batteries: Some of the hearing aids in the current market are equipped with rechargeable batteries, thus there is no frequent need for battery replacement.

• Customizable Programs: Listened programs can be changed according to the environment; for example, when the user is in a quiet room, quiet music will be played, or when the user is in a noisy restaurant, noisy music will be played.

• Remote Control and Applications: Enables users to have some form of control using their hearing aid through a remote control or an application installed on a smartphone.

• Tinnitus Masking: It generates white noises that can be used to manage tinnitus or ear ringing.

• Speech Enhancement: Enhances speech frequencies to reduce noise in the interacting parties’ conversations.

• Feedback Suppression: Helps to minimize, or even completely get rid of the whistling or feedback that may be realized with hearing aids.

• Binaural Processing: Enables two hearing aids to share information to help the user better navigate the space and determine the location of the sounds.

• Adaptive Sound Adjustments: Adapts to the context of the user in terms of the environment and the tasks that one is involved in.

• Fitness Tracking: Another new development in hearing aids is that some of them come equipped with sensors that monitor movement in a similar way to a fitness bracelet.

• Language Translation: New technology that recognizes spoken language in real-time and transmits the interpreted conversation to hearing aids.

Techniques for Using Hearing Aids:

An audiologist can select the correct hearing aid according to the need and necessity. Only if one maintains the hearing aid properly will it be beneficial to them, and its life will be extended. One should follow a few techniques to get used to it and maintain it.

1. How to Adjust With the Hearing Aid?

It will take time for one to adapt to the new hearing aid. However, practicing and using it regularly can help one out. With the help of the audiologist, one can practice how to put in and take out one’s hearing aid, how to clean it, how to differentiate between the right and the left side, and how to change the batteries. Clarify all doubts and make the necessary adjustments until one is satisfied with the aid. While using a hearing aid, keep in mind that one’s hearing will not return to normal, but it can only improve the hearing. It will take time to adapt to one’s new hearing aid, but one will quickly get used to it when one uses it regularly. Practice using it in different situations or environments. Have a follow-up with the audiologist to learn about the new hearing aids available on the market.

2. How to Care for One’s Hearing Aid?

To take proper care of the hearing aid, one should,

• Always keep it away from moisture and heat.

• The hearing aid should be cleaned regularly from all earwax and drainage from the ear.

• Hairspray or hair care products should not be used while wearing hearing aids.

• Switch off hearing aids when not in use.

• Dead batteries should be changed immediately.

• Replaced batteries and small aids should be kept away from children.

3. What Are the Difficulties In Using Hearing Aids?

• In the initial period, some people may feel uncomfortable while using the hearing aid.

• The user's voice may sound louder inside their head, and this is called the occlusion effect.

• Some whistling sounds can be heard due to the hearing aid.

• The hearing aid will not separate the sound one wants to hear and does not want to hear.

• People may hear some buzzing sound in the hearing aid when taken near cell phones due to cell phone's radio frequency interference.

4. How to Carefully Place a Hearing Aid?

• First, wash one’s hands.

• The hearing aid should be turned off, and the volume should be low while wearing the hearing aid.

• The earmold should fit appropriately to the ear; if not, it should be reshaped according to one’s ear.

• Place the earmold inside the ear, push it forward slightly, and place it in the canal.

• Then, press the earmold by slightly rotating it backward to snugly and comfortably in one’s ear.

Conclusion

In conclusion, modern hearing aids are small devices that contain numerous functions that are aimed at enhancing the quality of life of people with hearing impairments. These features not only improve the quality of the sound and speech but also improve their convenience and versatility depending on the user’s surrounding environment. From the reduction of noise to directional microphones and Bluetooth and artificial intelligence integration, hearing aids have become very personalized and easy to use. Hearing aids will continue to evolve with each passing day due to the advancement in technology, and this will remain key to providing the millions of people who require it an opportunity to get into their environment and be able to communicate effectively.