Hearing Aids
Hearing Aid Technology
Hearing aids come in a variety of designs and with a wide range of functions and features to address an individual's specific needs. The most basic components include a microphone, an amplifier, a receiver, and in the case of digital hearing aids a small computer. All digital hearing aids are not created equal. Many hearing aid users that have experienced various types of digital signal processing (DSP) technology are struck by the differences in sound quality that more advanced hearing aids offer. Things such as how quickly the hearing aid is able to adjust or adapt to changes in the environment play an important tole in the oveall naturalness of the amplified sound.
PROGRAMMING CAPABILITY - Most digital hearing aids on the market today allow the audiologist to program them using a computer. However, based on the type of product connected to the computer, the audiologist may not have all the controls necessary to fine-tune the hearing aid for specific issues or situations. Superior programming systems allow full customization of the product for very specific hearing loss and hearing needs.
CHANNELS - The greater the number of independent compression channels, the more accurately the hearing aid can be adjusted for various hearing loss configurations. Also, other key technologies that are offered in the hearing aid such as digital noise reduction, advanced adaptive directionality, and feedback management operate more effectiveloy with an increased numnber of channels.
DIGITAL NOISE REDUCTION - Noise reduction is a technology that is designed to improve listening comfort and to help improve hearing in noise. Noise reduction looks for steady-state sounds (which are typically noise) coming from all around the user and turns down these sounds when they reach a certain level. Noise reduction is applied when the signal (speech or music) and the noise become equally loud, or the noise becomes louder than the signal. This technology typically provides a comfortable listening experience. More advanced hearing aids use "automatic" noise reduction. The user no longer has to make a manual adjustment; it is all done automatically.
DIRECTIONAL TECHNOLOGY - Like noise reduction, directionality is a technology that is designed to help improve listening comfort and hearing in noisy situation. However, unlike noise reduction, directionality turns down all sounds coming from the sides and behind, instead of turning down steady-state sounds from all around the listener. Directional systems assume that the "desired signal" is the sound arriving from in front and "competing noise" is any sound originating from behind. Directional systems have been proven effective in assisting hearing aids users in better understanding conversations in noisy environments. "Automatic" directionality allows the directional signal to turn itself on or off based on the listening environment. Although directionality is preferred for noisy situations, it may not be the best choice for certain outdoor or quiet situations. If the hearing aid does not have automatic directionality, the user must manually turn this feature on or off as preferred.
FEEDBACK MANAGEMENT - The squeal or whistle that some users experience while wearing hearing aids usually happens when the hearing aid isn't fitting quite right or if the volume control is turned up too high. More advanced hearing aids have a special technology that allows the audiologist to remove the "squeal", also called "feedback", through a sophisticated cancellation technology without the user having to turn the hearing aid down and miss important conversations. The most advanced feedback cancellation systems on the market also adapt to changes in the environment so that the squeal is automatically removed.
USER ALERTS - User alerts provide notification when a change has occurred with the hearing aid. Modern hearing aids have far more capability than previous generations of product. Smart hearing aids help the user locate the correct listening program, determine whether the user is turning the volume up or down, locate the preferred listening, and remember to change the battery. The "smarter" the alerts, the easier it is to operate the hearing aids.
LISTENING PROGRAMS - Modern hearing aids provide several user options or controls that allow for the fine-tuning of the hearing aid for specific listening situations. Just as one may want to slightly adjust the controls on a car stereo to improve the sound quality of a particular song, hearing aid users may want to adjust the listening program on their hearing aids to improve the sound quality of a specific listening situation. Audiologists can customize these optional listening programs for a user's specific needs. Need a program that is designed for music? Listening on the telephone? Communicating in a noisy restaurant? The more programs, the more options.
TELEPHONE OPTIONS - One of the listening options available with certain hearing aid models is a telephone program. The telephone program can either be configured to work with the hearing aid's microphone or the hearing aid's telecoil (if available). If the hearing aid has a telecoil option, it has the ability to pick up the electromagnetic field generated by the telephone. Using the telecoil avoids the feedback that often results from putting a hearing aid against a telephone, and eliminates distracting background noise since the hearing aid is only picking up the signal from the telephone. More advanced hearing aids now offer a "automatic" telephone feature that eliminates the need to manually select the telephone program. Hearing aids with this feature automatically switch the hearing aid to the telephone program when the receiver is placed next to the ear.
Information provide by Sonic Innovations, Inc. (www.sonici.com)