Frequency Transposition hearing aids, what is available?
Paul Harrison at Your Hearing
The biggest problem with the older analogue hearing aids was that they just made everything louder. While this was fine for the sounds that were out of your normal audibility range, should a sudden loud noise occur, it was REALLY loud. It also meant that users were constantly having to adjust the volume as they changed environments because the hearing aids could not be programmed to adjust automatically.
Today’s digital hearing aids are far more advanced and use a different kind of technology. Rather than just amplifying all the sounds, they actually change the sounds so you can hear them. They do this by taking the frequencies that are out of your hearing range and moving them to a level that you can hear.
A great number of people with hearing difficulties suffer from a high frequency loss. This means that these frequencies need to be lowered to make them audible. Many hearing aids that are currently available have the ability to lower the frequencies and use two different methods to achieve this. These are referred to as Frequency Compression and Frequency Transposition.
Frequency Compression
This method takes the high frequency sounds that you can’t hear and moves them into a range below that level. This means that all the sounds are now compressed into a smaller region, increasing your range of audibility. The downside with this method is that all sounds are affected by the process, so, even the frequencies you can hear normally are automatically being compressed as well.
Frequency Transposition
With Frequency Transposition, the higher frequency sounds are still moved to the lower region but instead of being compressed, they are superimposed over the other frequencies. By using this method, the lower frequency sounds that are already in your audible range are not unnecessarily compressed. The transposed sounds simply mix with the lower frequencies, preserving the original signal structure. The downside with this method is that it can potentially cause the original sounds to be masked which can cause confusion for the wearer when they initially use the hearing aids.
Despite there being downsides to both methods, they have been proven to greatly improve hearing and give people the ability to hear sounds that would previously have been completely inaudible.
Many hearing aids in today’s market use some form of frequency compression or transposition to increase not only the range but also the quality of sound that you hear. They use a number of channels to process different ranges of frequencies. The more advanced models have more channels which allows the frequencies to be more finely tuned for individual hearing loss. Along with this, some manufacturers even have extra features that are designed to further improve the audibility range of these higher frequencies.
Below are three examples of manufacturers who use frequency compression or transposition along with a dedicated feature.
PHONAK Q RANGE
In 2012, Phonak upgraded their entire hearing aid portfolio with a new sound processing platform called Quest. With this they promised faster sound processing, increased clarity and through binaural technology, the ability for the hearing aids to communicate with each other.
The Phonak Q range offers up to 20 sound processing channels, depending on the model, which allows precise tuning of the hearing aid in terms of frequencies. Along with this they have SoundRecover; which is an additional feature that brings the high frequencies down into your audible range.
WIDEX DREAM/SUPER
These are the newest additions to the Widex family of hearing aids. They were launched in 2013; with the Dream designed for most hearing losses; and the Super specifically for severe to profound loss. Both of these hearing aids offer up to 15 sound processing channels and an Audibility Extender; which is the feature for managing the high frequencies. The Super also has a unique feature called Output Extender; which also works for a low frequency loss as it boosts the sounds that are below 1 kHz.
SIEMENS MICON RANGE
The Siemens Micon range was launched at the end of 2012 and offers many styles and technology levels. The most significant addition was the introduction of their new 12 kHz bandwidth; which has led to an impressive maximum 48 sound processing channels on the most advanced models. The Micon range also features SoundBrilliance; which not only brings the frequencies into your audibility range; but also makes them as clear as possible.
This is not an exhaustive list as nearly all manufacturers feature this frequency compression/transposition technology in their hearing aids. With manufacturers giving more and more dedication to research, advancements are happening all the time. This means that technology can only get better, giving people the ability to hear sound where there previously was none.
Tune into our blog next Monday to read about The Top 5 Super Power Hearing Aids on the Market.
About the Author: This article was produced by Paul Harrison. Paul has over 20 years’ experience in the hearing aid industry. The Your Hearing Aid Specialists provide all leading hearing aid manufacturers/models and offer their service through their UK network of hearing aid audiologists.
