It is estimated that more than 28 million people in the United States have severe hearing loss. For the majority of these people, a hearing aid is probably the best way to improve their hearing. Recent advances in hearing aid technology mean that modern hearing aids have a high level of sound quality in a very small device. It should be noted that the hearing aid will not restore normal hearing. What it can do is make it easier for the user to detect and interpret sounds. Often a person with a hearing loss will not even notice if someone is trying to talk to them. This is what the stethoscope will help with.

Even though there are many different kinds of hearing aids available today, they all function similarly. Sound waves are picked up by a microphone, or receiver, which transforms them into an electrical signal. After processing, this signal is routed to an amplifier, which recreates the audio signal. The frequencies that the user has trouble hearing are amplified by the processing. Users of hearing aids can hear speech at a volume that is comfortable for them. It could require some time for the brain to get used to the new messages it is receiving.

The use of hearing aids isn't ideal because of some restrictions. They won't eliminate background noise or bring back normal hearing. It can be adjusted, though, to lessen background noise. When they first get hearing aids, people frequently remark that they sound odd to themselves and that relatively loud noises from outside street traffic and refrigerator fans irritate them. But once their brains had a chance to adjust to their new hearing aids, background noise starts to get filtered out to a more comfortable level.