What Types Of Hearing Aid Technology Are Available?

There are essentially three levels of hearing aid technology. We refer to these as analog, digitally programmable, and digital. At CSG Better Hearing Center, we dispense only the highest level of technology, which is digital hearing instruments.

ANALOG technology is the technology that has been around for many decades. Analog technology is basic technology and offers limited adjustment capacity. It is rarely used today and is becoming obsolete.

DIGITAL technology is the most sophisticated hearing aid technology. Digital technology gives the audiologist maximum control over sound quality and sound processing characteristics. There are qualitative indications that digital instruments do outperform digitally programmable and analog hearing aids. Digitals are not perfect, but they are very good. Digital hearing aids have been widely available since 1996 and Mike Hall, an Audiologist and owner/partner at CSG was the first to wear this in the US. The digital technology ranges from basic to advanced devices. A person’s lifestyle is the determining factor to decide which will be most beneficial.

EXTENDED WEAR technology has been available since January 2007. Our offices were the fourth to start using this revolutionary technology. The device is worn 24 hours a day for up to four months at a time. It is inserted deep into the ear canal by an audiologist. Due to the location, the sound quality is significantly better and more natural than traditional devices which was proven in a study performed in our offices in 2008 with 101 patients.


ReSound hearing aid family lineup


ReSound rechargeable hearing aids shown in charger

What Is Digital Hearing Aid Technology?

The term ‘digital’ is used for most of today’s current technology, from televisions to cell phones. Hearing aids today are also digital, meaning incoming sound is converted into a series of numbers, which is then processed using mathematical equations. Digital processing enables very complex manipulation of sound, for example, to separate speech from noise.

The digital technology within hearing aids also allows to separate sound into different frequency regions and amplify each region selectively, depending on the hearing aid wearer’s hearing loss. The processing within hearing aids also enables different amounts of amplification for soft, moderate, and loud sounds, so sounds are audible, but loud sounds are not uncomfortable or over amplified. And, digital processing enables a natural sound quality with minimal distortion, resulting in excellent sound quality.

Digital hearing aids are programmable, meaning the hearing aid settings can be precisely fine tuned and special features can be adjusted for each wearer by a hearing aid professional, using special hearing aid software on a computer. Hearing aids are programmed and customized for both the hearing loss and the preferences of the person who wears them.

Hearing Aid Technology

A wide range of technology and a whole host of features are available in each hearing aid style. The cost of hearing aids generally depends on the technology and the number of features the instrument has, and not necessarily on the style selected.

Today’s digital hearing aids are typically offered in various levels such as basic or entry-level to advanced or premium-level. Within each level, different technology and features are available.

Basic digital hearing aids generally require the wearer to make some manual adjustments in certain listening environments such as turning a volume control up or down, or pushing a button to change listening programs. In contrast, a premium or more advanced hearing aid responds automatically to changes in the listener’s environment, making changes based on the signals being detected by the hearing aid. The hearing aid wearer is not required to make any manual changes.

As the level of the technology increases in hearing aids, so do the availability of advanced features. Examples of some of the advanced features found in today’s digital hearing aids are shown below.

  • Directional Microphones – Applies preference to sounds in front of the wearer and reduced sound from behind the wearer. This technology has been proven in studies to improve speech understanding in background noise.
  • Noise Reduction -Determines if signal contains unwanted background noise and reduced level of background noise if present. Background noise is less annoying and hearing aid wearer’s listening comfort is improved in noisy situations.
  • Feedback Management – Reduces or eliminates whistling that can often occur with hearing aid use. Hearing aid wearer’s comfort is improved from annoying whistling.
  • Wind Noise Reduction – Reduces the noise created from wind blowing across the hearing aid’s microphone(s). Designed to improve comfort for persons who spend a lot of time outdoors.
  • Data Logging/Learning – The ability of the hearing aid to track and learn the hearing aid wearer’s preferences in various listening environments. This information can assist the hearing professional in making future programming adjustments and allows the hearing aid to adapt to the wearer’s preferences.
  • Bluetooth Interface – Establishes a wireless connection between hearing aids and Bluetooth compatible devices. Designed to improve wearer convenience and use with devices such as cell phones, MP3 players, computers, etc.

FAQs

How Do Hearing Aids Work In The Presence Of Background Noise?
Background noise exists and is important to hear in order for the hearing aid user to be involved in their environment. There is no way to completely eliminate background noise, however, technology exists today to reduce distracting noise and allows you to focus better on the person you want to hear. Directional microphones are available and are useful as they help to focus the amplification in front of you, or towards the origin of the sound source. Directional hearing aids can offer a better signal-to-noise ratio in difficult listening situations by reducing a little bit of the noise from the sides or behind you. In most 100% digital hearing aids, the noise control features help make noise more tolerable, but do not completely eliminate the noise.

Remember, when you had normal hearing there were still times when background noise was a problem. It is no different now, even with properly fit hearing aids! The good news is there are circuits and features that help to reduce (or minimize) background noise and other unwanted sounds. In fact, there are research findings that demonstrate digital hearing aids with particular circuit and microphone options can effectively reduce background noises.

Many early digitally programmable (and even some digital) circuits, which claimed to reduce or eliminate background noise, actually filtered out low frequency sounds. This indeed made the sounds appear quieter, however, not only was the background noise made quieter, but so too, was the signal (the speech sound).

Newer ways to reduce background noise are based on timing and amplitude cues and other noise processing strategies, which 100% digital hearing aids can incorporate. These methods work, but are not perfect.

The best and most efficient way to eliminate or reduce background noise is through the use of FM technology.

What Is A Middle Ear Implant?
In order to be fit with a Middle Ear Implant (MEI), one requires a purely sensori-neural hearing loss. Since MEIs are better at generating mid- and high-frequency gain than low-frequency gain, the optimal hearing loss should be sloping. Many MEIs can be digitally programmed or are in fact digital. With the extra control that these technologies afford, other sensori-neural configurations can be fit. Although the various surgeries are not complicated, they can be lengthy (up to 3 hours) and like any surgery, can be traumatic. An MEI candidate is therefore one who has tried conventional hearing aids and was unsuccessful either because (i) they were not able to obtain as much high-frequency amplification as required, or because (ii) the occlusion effect (Vagal response) could not be resolved to the satisfaction of the patient. While the cosmetic issue is important, I am not convinced that this should be the primary deciding factor, given that CIC hearing aids can be made quite small with newer technology. There are several companies working on new MEIs that are in the experimental phase.