Hearing Aids
About Hearing Aids
A hearing aid is a small electronic device that is worn in or behind a person’s ear. It processes sounds and amplifies them so that they are audible for a person with hearing loss. In the past, hearing aids focused primarily on enhancing communication, but modern hearing aids focuses on improving the quality of listening in individuals, whereby providing comfortable listening. Statistics show that ninety percent of the people with hearing loss benefits greatly from the use of hearing aids.
As technology advances, hearing aids are changing both in size and quality. Digital programmability of hearing aids have made them extremely versatile and enabled fitting to a wide range of patients depending on their degree and type of hearing loss.
Parts of a Hearing Aid
Functionally, hearing aid can be divided into three blocks: 1. The microphone 2. The amplifier and, 3. The receiver or speaker. The microphone picks up the incoming sound and sends it to the amplifier circuit. The amplifier processes the signal and feeds it to the receiver. The receiver transmits the processed sound into the ear of the user.
Even though the location of structures varies from manufacturer to manufacturer, basic external features are shared by most hearing aids. They include Microphones, On-Off switch, Battery compartment, the volume control, program selection switch, connection tube/ear hook/ear tip and the dome/ear mold or receiver. To reduce the size of hearing aids, sometimes the on-off switch is designed to work as volume switches or programming switch depending on the duration of pressing the button
Different types of hearing aids
Hearing aids can be broadly classified into two main groups: in-the-ear (ITE) styles and behind-the-ear (BTE) styles.
ITE styles
Invisible-in-the-canal (IIC) and completely-in-the-canal (CIC) hearing aids are the smallest hearing aids to date. They fit very deeply in the ear canal and are typically fit for mild or moderate hearing losses. Their size and ability to “disappear” when worn depend on the size of the ear canal. Because of their tiny size, they offer high cosmetic appeal for people who desire a discreet solution.
In-the-canal (ITC) hearing aids sit in the lower portion of the concha part of the external ear, making them comfortable and easy to use. Because they are slightly larger than IIC and CIC styles, they have a longer battery life, are easier to handle and can fit a wider range of hearing losses.
BTE styles
Behind-the-ear hearing aids, as their name suggests, are worn behind the pinna of the user. The sound is carried to the ear canal by a very thin ear tubes and an ear tip that fade discreetly into the ear canal. They have enough physical space to house features for a variety of hearing losses. Owing to the larger form factor, these hearing aids have easy to manipulate manual controls and longer lasting batteries. For higher degrees of hearing loss, ear molds have to be used to prevent the leakage of amplified sound from the ear canal of the user.
Mini BTE hearing aids with slim tubes and tips: Mini BTE styles are designed to hide behind the outer ear and have ultra-thin tubing to discreetly route sound into the ear. This style is so popular that a greater variety of ear tips have become available in order to accommodate a greater degree of hearing loss with the mini BTE.
Receiver-in-the-ear (RITE) or receiver-in-canal (RIC) hearing aids: RITE and RIC styles have the receiver (speaker) built into the ear tip instead of the main body of the hearing aid. This allows the speaker of the hearing aid to be positioned closer to the eardrum while the microphone and processor sit in a tiny case behind the ear.
Professionals involved in Hearing Aid fitting
The professionals involved in Hearing Aid fitting and prescriptions are the Audiologist and the Hearing Instrument Practitioners. A health care professional who is trained to evaluate hearing loss and related disorders, including balance (vestibular) disorders and tinnitus (ringing in the ears) and to rehabilitate individuals with hearing loss and related disorders. A Hearing instrument practitioner/specialist is a professional trained to handle various types of hearing aids and assistive listening devices.
Care and Maintenance of Hearing Aid
Hearing aids are electronic devices with many sensitive components. Hence it is of utmost importance to treat the hearing aid with care in order for it to function longer and minimize potential problems during daily use. Hearing aids are often robust but they may not be able to withstand long periods of abuse.
It is important to keep the hearing aid away from dirt and moisture. Making sure that hands are clean and dry before touching the hearing aid is a good way to prevent the clogging of the small microphone inlet.
Removing hearing aids before showering, swimming or during the rain prevents moisture from entering the device. It is generally advised to clean the hearing aids every day with a dry cloth and keep the device in dehumidifier boxes over night to ensure longevity of the device.
Keep the hearing aids away from pets and avoid exposing them to hair spray. When hearing aids are not used for a while, remove the batteries and keep them separate from the aid.
Never attempt to open the casing or repair the hearing aids. The circuit of hearing aids is very sensitive to static electricity and may be irreversibly damaged by any attempt to open the casing.
The Hearing and Balance Centre is founded by Mohammad S Asghar, (Doctor of Audiology, CASLPO Audiologist).