Thursday, July 16, 2009

Hearing Aids

What are the different styles of hearing aids?

In-the-canal and completely-in-the-canal aids: These aids are contained in a tiny case that fits partly or completely into the ear canal. They are the smallest aids available and offer cosmetic and some listening advantages.
In-the-ear aids: All parts of the aid are contained in a shell that fills in the outer part of the ear. These aids are larger than canal aids, and for some people may be easier to handle than smaller aids.
Behind-the-ear aids: All parts are contained in a small plastic case that rests behind the ear; the case is connected to an earmold by a piece of clear tubing. This style is often chosen for young children for safety and growth reasons.
The majority of hearing aids sold today are canal hearing aids and in-the-ear hearing aids.
There are also special hearing aids built to handle very specific types of hearing losses. For example, a bone-conduction hearing aid uses a headband and a bone vibrator for individuals who have no ear canal or outer ear. There are hearing aids that route sounds coming to one ear over to the other ear for use by individuals who have no hearing in one ear. In special cases, hearing aids can be built into glasses for individuals who need that type of fitting. There are hearing aids available that can accommodate virtually any kind of hearing loss!

What types of hearing aid technology are used today?

Hearing aids are distinguished by their technology or circuitry. In the early days, hearing aid technology involved vacuum tubes and large heavy batteries. Today, there are microchips, computerization, and digitized sound processing, used in hearing aid design.

* Conventional analog hearing aids are designed with a particular frequency response based on your audiogram. The audiologist tells the manufacturer what settings to install. Although there are some adjustments, the aid essentially amplifies all sounds (speech and noise) in the same way. This technology is the least expensive and it can be appropriate for many different types of hearing loss.

* Analog programmable hearing aids have a microchip which allows the aid to have settings programmed for different listening environments such as quiet conversation in your home, noisy situations like a restaurant, or large areas like a theater. The audiologist uses a computer to program the hearing aid for different listening situations depending on your individual hearing loss profile, speech understanding, and range of tolerance for louder sounds.

Some aids can store several programs. As your listening environment changes, you can change the hearing aid settings by pushing a button on the hearing aid or by using a remote control to switch channels. The aid can be reprogrammed by the audiologist if your hearing or hearing needs change. These aids are more expensive than conventional analog hearing aids, but generally have a longer life span and may provide better hearing for you in different listening situations.

* Digital programmable hearing aids have all the features of analog programmable aids but use "digitized sound processing" to convert sound waves into digital signals. A computer chip in the aid analyzes the signals of your environment to determine if the sound is noise or speech and then makes modifications to provide a clear, amplified distortion-free signal. Digital hearing aids are usually self-adjusting. The digital processing allows for more flexibility in programming the aid so that the sound it transmits matches your specific pattern of hearing loss. This digital technology is the most expensive, but it allows for improvement in programmability, greater precision in fitting, management of loudness discomfort, control of acoustic feedback (whistling sounds), and noise reduction.

What are some of the special features available in hearing aids?

Many hearing aids have optional features that can be built in to assist in different communication situations. Some options are:

* Directional microphone. Some hearing aids have a switch to activate a directional microphone that responds to sound coming from a specific direction, as occurs in a face-to-face conversation. You can switch from the normal non-directional (omnidirectional) setting, which picks up sound almost equally from any direction, to focus on a sound coming from in front of you. When the directional microphone is activated, sound coming from behind you is reduced.

* Telephone switch. Some hearing aids are made with an induction coil inside. You can switch from the normal microphone "on" setting to a "T" setting in order to hear better on the telephone. (You should know that all wired telephones produced today must be hearing aid compatible). In the "T" setting, environment sounds are eliminated, and you only pick up sound from the telephone. Furthermore, you can talk without your hearing aid "whisting" because the microphone of the hearing aid is turned off!

The "T" setting can also be used in theaters, auditoriums, houses of worship, etc., that have induction loop or FM installations. The sound of the talker, who can be a distance away, is amplified significantly more than any backgroundnoises. Some hearing aids have a combination "M" (Microphone) / "T" (Telephone) switch so that, while listening with an induction loop, you can still hear nearby conversation.

* Direct audio input. Some hearing aids have a direct-audio input capability that allows you to plug in a remote microphone or an FM assistive listening system, connect directly to a TV, or connect with other devices such as your computer, a CD player, tape player, radio, etc.

Will hearing aids eliminate all my communication problems?

With hearing aids, you will hear some sounds you have not heard previously or sounds you have not heard in a long time. At first, background noise may seem loud and distracting. Your own voice may sound louder.
It can take several weeks to months to become adjusted to listening with your hearing aids. Your audiologist will provide hearing aid orientation for you as well as audiologic rehabilitation as needed, which will enable you to communicate more effectively with your hearing aids.
Are there other hearing devices that will help me hear with or without my hearing aids?

Hearing aids, very helpful in one-on-one communication, are not the only technology available. for large area events, such as movies, theaters, large meetings, classrooms, or public halls.
Hearing assistive devices (also known as assistive listening devices) are available for use alone or in combination with many hearing aids. These devices provide extra help in specific listening situations, such as the telephone, noisy backgrounds, or small or large group listening settings (e.g., restaurants, concert halls, movie theaters). Your audiologist can advise you about assistive technology that might help with your particular listening needs.