Hearing Aids - Digital Types, Cochlear Implants and Limitations

Hearing aids are based on the same principles and carry sound from the environment to the ear. However there are several types of hearing aids depending upon the sizes and the style in which they are placed in the ear.

BTE (behind the ear)

ITE (inside the ear)

CANAL AIDS

Cochlear Implants

BTE HEARING AID

Features-

Useful in mild to profound hearing loss

The most visible and larger of all the devices

Provides greater amplification than any other device

Age criteria- it is suitable for all age groups. But generally used in children.

Mini BTE HEARING AID (sits on-the-ear)


ITE HEARING AID

Features-

Useful in mild to severe hearing loss

More visible to others

This device may pick up the wind sounds

Easier to use

Batteries are larger and last longer

Some ITE’s may have a telecoil. This magnetic coil makes it easier to hear telephonic conversations. Telecoil also helps people hear in public places (like airports, auditoriums, schools, temples/churches) having special sound systems called induction loop systems.

Age criteria-

Not advisable in children because the casings need to be changed as the ear grows.


CANAL HEARING AID

Types-

ITC aid (in the ear canal) - fits the size and shape of the individual’s ear canal.

CIC (complete in ear canal) – this hearing aid completely gets hidden in the ear canal.

Features-

It is least noticeable

Since it is covered by the ear there is least possibility of picking up air sounds

Easy to use for telephonic conversations

Is useful only in mild to moderate hearing loss

Adjusting and removing the aid is difficult

Less availability of space for batteries and other devices like directional microphones, telecoil.

Smaller batteries have to be used which do not last longer

Age criteria- not advisable for young children.

NEW TYPES OF HEARING AIDS (COCHLEAR IMPLANTS)-

Middle ear implant (MEI)

It is attached to one of the bones of the middle ear. This device moves the bones directly rather than amplifying the sound. This strengthens the sound vibrations entering the inner ear and is helpful to people with sensori-neural hearing loss.

Bone anchored hearing aid (BAHA)

It is attached to the bones behind the ear. This device transmits the sound vibrations to the inner ear from the skull. The middle ear is bypassed in this process. BAHA’s are generally used by people with problem in the middle ear.

Surgery is required to implant MEI and BAHA, therefore some hearing specialists may feel that there are more risks than the benefits.