In many hearing aids, there are no knobs or controls, because the instruments automatically adjust loudness levels. Some hearing aids are programmed so that they require only the push of a button on the hearing aid or on a wireless remote control to move to different listening situations and provide balanced sound in the home, on the telephone, or at a concert. Digital and digitally programmable hearing aids have been introduced that amplify signals in new ways and make the benefits of hearing aids even more customized. Many hearing instruments are virtually computers with flexible and sophisticated processors that analyze and respond to specific sounds. Some advanced hearing instruments process sound more than a million times per second to adapt to different environments.

Conventional Hearing Aids
Conventional hearing instruments, until approximately 1984, were the backbone of the hearing aid industry. The technology is termed conventional because these instruments utilize basic linear or analogue/fixed electronic circuitry. These linear instruments, while adjustable for volume and usually for slope (tone) process sound in a straight mathematical fashion, providing in theory, equal amplification at all key frequencies in the speech range. Usually, these products are selected by overall acoustic gain (amount of amplification required), slope (frequency response) and total output. The circuit and individual models are prescribed for the patient based on their individual test results and hearing evaluations.

This first level of technology is available in all styles of hearing aids from B.T.E. (Behind-the-Ear) to C.I.C (Completely-in-the-Canal) (smaller) models. Usually, linear products are not ideally suited for patients who recruit, have loudness tolerance problems or steep slope losses. However, these aids are currently the lowest in price in the marketplace which is an important consideration. They are widely used in Europe and in lesser developed countries. Market share of conventional products is steadily declining in the United States with the recent developments in 100% Digital and Programmable technology.

Advanced Technology Hearing Aids
Advanced technology hearing instruments differ from conventional products and offer advantages over them in that they generally utilize more recent developments in amplification electronics such as compression technology and automatic signal processing circuit designs. The circuits in this level of technology are modified linear electronics that develop more natural loudness (amplification) throughout the patient's listening range without over amplifying or under powering at discreet frequencies. The result is more comfortable listening, especially in noise and in general for patients who have loudness tolerance problems. In other words, the circuits produce sounds that are more natural, balanced and comfortable in most listening environments.

Circuit designs used in this level of product include the popular K-Amp®, Automatic Signal Processing (A.S.P.), Automatic Gain Control (A.G.C.), Class "D" Circuits, input compression, output compression, variable compression and Adaptive Compression® (Patented by Telex Corp.). Advanced technology linear (analogue) instruments are available from most major domestic manufacturers (brands) and come in a full range of sizes (styles) from B.T.E. (Behind-the-Ear) down to the smallest C.I.C. (Completely-in-the-Canal).

Digitally Programmable Analogue Instruments
This level of technology is what we would term an advanced electronic instrument that is essentially linear in nature, in terms of processing but is programmed to the patients individual needs via digital programming. Examples of this technology are the RESOUND®  hearing aid which was originally developed by AT&T Bell Labs and programmable SEQUEL® as developed by Starkey Labs.

Programmable circuit features allow the hearing instrument to be variably reset and adjusted (via an external computer platform and software) closely to the patients targeted needs. The advantages are the more precise acoustic adjustments that can be made when the product is fitted to the patient. More exact variable adjustments to individual patient preferences can be easily made while wearing (fitting) the aids during the fitting process and the patient can "test drive" different settings in various created environmental conditions (quiet, cafeteria noise, traffic, theater, groups at cocktail parties, etc.) Digitally programmable hearing aids are programmed and adjusted via a computer without having to be returned to the manufacturer, but because they process sound using linear electronics (analogue), they are not classified as 100% digital.

Obviously, programmable technology offers terrific flexibility and most of the products on the market have full menus of features available, including multi-channels, wide dynamic range compression, automatic signal processing, multiple and directional microphones, crossover frequency transition points, telephone features, remote controls (for dexterity problems), reverse slopes, etc. The primary bottom line advantages are...

• Adjustable sound enhancement while wearing the aids and as your individual hearing needs change over time.
• Enhanced sound processing circuits that can adjust to the environment and reduce to some degree the interfering effects of background noise.
• More relaxed listening in most situations.

The digitally programmable instruments have gained significant market share in recent years and are continuing to grow in popularity.

The majority of our patients, in all of our offices are opting for these products and 100% digital instruments, because they work.

100% Digital Hearing Aids - now more than 80% of all new instruments sold
Digital processing is indeed, the wave of the future and the market share of all digital products is growing rapidly - in TV's, cell phones, movies (D.V.D's), domestic appliances, C.D.'s and in hearing instruments. From an engineering viewpoint, digital processing, which processes sound mathematically, bit by bit in binary code is much cleaner, crisper and more stable than analogue processing. It offers better overall performance and is relatively easy to update, modify and revise, thereby providing superior consumer satisfaction in hearing instruments as well as in C.D.'s ( think of the comparison of sounds from C.D.'s to pre-recorded tapes and vinyl L.P.'s).

Digital hearing instruments are not just "new high priced toys" - they are indeed better hearing aids for most patients depending on two (2) major factors...

1. The brand (manufacturer) and its digital architecture (platform of hardware and software) and...

2. The professional (specialist or audiologist)  fitting and programming the instruments.

It is absolutely vital to note that in both 100% digital and in digitally programmable products, all brands are not created equal. There are clear winners and losers  in technology development and therefore  consumer satisfaction (results). Some manufacturers are patently two (2) to three (3) years ahead of others in digital research and development, experience and in bottom line quality of performance. With 100% digital and digital programmable instruments, expect to pay more - technology is expensive - but don't make the mistake of purchasing on price alone. There are cheap digitals on the market and you truly  do get what you pay for... 2nd and 3rd tier products that are actually not much better than conventional aids. Add to this poor programming by the people who market them and you'll be a very unhappy camper. Selection of the best professionals is the key to correct or best brand applications and programming.

In summary, the major benefits of 100% digital hearing aids are... Preciseness of digital computer technology providing greater accuracy in fitting individual patients. Programmability. Flexibility for total "custom" aided responses. In-situ measurements. Control of acoustic feedback (whistling). Noise reduction and less distortion. Automatic control of signal levels. Self-adaptive adjustments to changing acoustic environments. The best brands actually sample surrounding environments and adapt to those changes in milliseconds. Improved signal to noise ratios. Improved telephone adaptability. Self-monitoring capabilities such as low battery warning systems. Compensation (compression) for frequency specific recruitment. Multiple memories for various listening situations (optional). Completely automatic volume controls for soft high frequency sounds and less volume for louder low frequency sounds. Smaller component (Chip) size resulting in smaller hearing aids. Directional microphones that really work! Ability to revise individual patient prescriptions should hearing loss change. More relaxed listening in most situations. - Listen to the sounds of life again.

Levels of Hearing Aid Technology

Fully Digital Technology Currently the Most Advanced Level of Hearing Aid Technology Superior Sound Quality Completely Automatic** Fully Digital Signal Processing Between Microphone and Receiver Fully Digital Amplification Minimizes Cellular Telephone Interference 'Superior' Listening Comfort In Many Environments Processes Speech and Noise Differently Advanced Fitting Flexibility

Digitally Programmable Analogue Currently a Moderate Level of Hearing Aid Technology Good Sound Quality Fully Analogue Amplification Digitally Programmed Only 'Good' Listening Comfort In Many Environments Advanced Fitting Flexibility

Conventional Analogue Technology Currently the most basic level hearing aid technology Good Sound Quality Fully Analogue Signal Processing Fully Analogue Amplification 'Good' Listening Comfort In Many Environments Limited Fitting Flexibility

** Automatic Performance may not be available in all digital hearing instruments.

Hearing Aid Special Features
Almost all hearing aids within the various technologies are custom ordered to fit your ears and your specific hearing loss (prescriptive fitting). Most custom hearing aids can be equipped to specification with a number of special features to meet your communication and physical needs...

• Directional microphones.
• Telephone Switch:Special feature that allows you to utilize your hearing aid directly into the phone.
• Compression Circuitry: Helps prevent loud sounds from exceeding your comfort level.
• Class "D" Circuitry: Provides an enhanced high frequency response with less distortion and improved sound quality.
• Push-Pull: Provides additional power for patients with severe loss.
• Push Button, Toggle or Raised Volume Control: All excellent options for people with limited fingertip sensitivity or dexterity problems. (For example, stroke victims).
• Signal Processing: (ASP) Circuitry or K-Amp: Helps improve speech understanding in noisy situations.
• Remote controls.
• Rechargeable Hearing Aids: for patients who can not change batteries or secure batteries on a regular basis. Used in many nursing homesand excellent for remote locations (undeveloped countries, aboard seagoing vessels, etc.).

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