Today's Hearing Aids

Today's hearing aids come in many different shapes and sizes. The quality of hearing aids has changed dramatically since the days of Alexander Graham Bell, who invented the telephone in an attempt to produce an amplifier for his hard-of-hearing mother. And, the size has become smaller since the days when the hearing aid was so large, the battery had to be strapped to the wearer's ankle. Today's hearing aids have achieved CD quality sound and the size of hearing aids are about the size of a contact lens - virtually undetectable.

Types of hearing aid technology

There are five types of circuits that, in most cases, can be incorporated into any size hearing instrument. In general, programmable and digital technologies offer the most flexibility and more options to address user comfort and speech intelligibility.

Digital:
A digital circuit is the most sophisticated circuit on the market today. This circuit is programmed through a computer and usually has at least two channels. Each channel in a digital circuit is controlled independently of the others, and controls a certain range of pitches coming into the hearing instrument. This circuit has fine tuning ability to match individual hearing requirements and filter out certain unwanted sounds. What sets this circuit apart from analog circuitry is that the sounds are processed digitally, which should result in a clearer signal. Another advantage of some digital circuits is that they analyze surrounding sounds to maximize soft speech-like sounds, while minimizing louder steady state noises, such as traffic or wind.

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Programmable:
A programmable circuit is much more sophisticated than the linear and basic compression circuits, and as its name implies, it is programmed through a computer. This allows the hearing aid to be set more precisely for the user's comfort and sound quality. Programmable technology also allows for adjustments to hearing needs over time, as the instrument can often be re-programmed to meet a changing hearing condition. Programmable hearing aids can be either digital (see above) or analog.

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Directional:
Directional technology utilizes sophisticated microphones to determine which sounds are desirable, based on the direction from which they are coming. Usually hearing aids with directional capability can function in an Omni directional mode (using just one microphone) -to allow sounds coming from all directions -or in the directional mode, which will attenuate sounds coming from the undesirable direction. The advantage of directional hearing aids is that unwanted sounds coming from a certain direction are reduced, ie; background noise coming from behind.

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Compression:
Compression addresses the need to provide a comfortable range of amplified hearing, particularly for loud sounds. In trying to make soft and average sounds loud enough to be heard, loud sounds may become uncomfortably harsh and loud. Compression technology limits the amount of amplification at certain levels, making the listening experience more comfortable for the hearing aid user.

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Linear:
A linear circuit makes EVERYTHING louder. This type of circuit is more limited in its ability to meet individual hearing needs. Because of its limited functionality, linear technology will meet the most basic hearing needs and be the least costly alternative. Conventional hearing instruments are obsolete. But the extended wear hearing devices on the market are of this technology and are not obsolete.