my baby's hearing
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Hearing Aid Choices
How does a hearing aid work?
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All hearing aids have the same basic parts. In the behind-the-ear hearing aid shown here, you can see the microphone, the tonehook or earhook, the volume control, the on/off switch and the battery door.

The microphone picks up sounds and sends them to an amplifier that makes them louder. The hearing aid will make some pitches of sound louder than others, depending on the shape of the hearing loss. Your audiologist uses the hearing aid's internal controls or computer programming to adjust the sound for your child's needs.

earmold After sounds are made louder, they go through the earhook to an earmold that is custom made for your child. The earhook is a small plastic piece that holds the hearing aid on the ear. Earmolds are made from a mold or impression of your child's ear. They are made from soft materials and fit in the outer ear and ear canal. Since it is so important for earmolds to fit snuggly in the ear, they will need to be replaced as your baby grows. When children are small, earmolds may need to be replaced every 2-6 months. They are available in a variety of colors, including skin tones and bright ones.

Hearing Aid Gain

The graph below shows how much a hearing aid increases the loudness of sounds at different pitches or frequencies. The increase in loudness is called "gain". For milder hearing losses, a small amount of gain is needed. A severe hearing loss needs more gain. When the amount of hearing loss is different across frequencies, the audiologist must adjust the gain of the hearing aid differently for different frequencies.



Figure 1: In this example, gain ranges from 40-65 dB for a relatively
flat hearing loss (shown here using a solid line). Very little gain is
provided for the low pitches in the case of a high pitch hearing loss
(shown here using a dashed line).