Hearing aids are a common non-invasive treatment option for hearing loss. A hearing aid is a small electronic device worn in or behind the ear to amplify sounds. While hearing aids are useful in improving listening and communication, they do not cure hearing impairment or make the ear function normally.
A hearing aid includes three components: a microphone, an amplifier and a speaker. Sounds are received through the microphone, intensified by the amplifier, and transmitted to the ear through the speaker.
The microphone, which picks up sounds from the air, converts them into electrical signals. Once these sounds have been made more powerful by the amplifier, they are changed back into acoustic signals to be heard by the person wearing the hearing aid. In addition to these three components of hearing aids, digital hearing aids also make use of a small computer.
As hearing aids amplify sounds, hair cells within the ear detect these sounds and convert them into signals to pass to the brain. Hearing aids do not work for every person with a hearing impairment. The issues of those with receptive hearing difficulties may not be resolved by hearing aids since the devices are only able to increase volume, not reception. For those individuals, the problem is akin to listening to a radio with static. No matter how loud you turn the volume up, the static remains.
Types of Hearing Aids
There are three basic styles of hearing aids that vary in size, placement and degree of amplification. Determining which style is best for the individual depends on the severity of the hearing loss.
Behind the Ear (BTE)
These hearing aids are worn behind the ear and connected to a plastic mold that is placed inside the outer ear. They are utilized by individuals with mild to profound hearing loss. New technology has introduced a smaller BTE aid consisting of only a small tube placed into the ear canal. This has the advantages of keeping the canal open and protecting the device from damage due to wax buildup. This smaller BTE also provides a clearer sound.
In the Ear (ITE)
These hearing aids are smaller devices that fit inside the outer ear. They can be used for mild to severe hearing loss but are not typically used for children since they will be quickly outgrown.
In the Canal (ITC)
In the canal aids are the smallest type of aid and fit either partially in the canal, ITC, or completely in the canal, CIC. Because canal aids are so small, they may be hard to adjust and have very limited space for batteries and other devices. Canal aids, therefore, are most frequently recommended for individuals with mild to moderate hearing loss.
Regardless of style, hearing aids work in two different ways depending on how they are electronically programmed.
Analog Hearing Aids
These aids convert sound waves into electrical signals which are then amplified and transmitted back to the ear. They can be custom-made to fit each patient's hearing needs. They can altered by the patient and customized for different listening environments. Analog aids can be used in any style of hearing aid.
Digital Hearing Aids
Digital hearing aids convert sound waves into numerical codes and then amplify them. Some frequencies can be amplified more than others. Digital aids can also be programmed to focus on sounds coming from a certain direction. These aids tend to be more expensive than the analog variety.
Individuals considering the purchase of hearing aids should consult with their doctors in order to make the most sensible choice. Since hearing aids are a costly investment, most manufacturers allow a 30-60 day trial period after purchase to make sure the devices are beneficial for the particular patient. Hearing aids are often a very worthwhile investment for many individuals, resulting in improved hearing and the ability to communicate and socialize.
- National Institutes of Health
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine