What do those technical terms mean?

What do those technical terms mean?

Here are some of the most common technical terms that will come up when you’re researching hearing implant systems.

Battery life

This is the length of time your device will work before you have to recharge or change the batteries. If you’re getting your implant on the NHS, you’ll be provided with batteries. If you’re a private patient, you’ll need to buy your own and can choose the type that best suits your needs – for instance, if you’re travelling to a remote region, disposable batteries may be better than rechargeable ones.

However, it’s not simply a question of choosing the right brand or type of battery. The implant system you choose is also important. With some implant systems, battery life is directly affected by adjustments to coding strategy made by the audiologist at each fitting. So a change to a coding strategy that gives a better performance may use up battery power faster. However, with other brands, the use of coding strategies doesn’t affect battery life. In this case, you can expect a fixed battery life.

An individual’s skin flap thickness may also affect battery life.

Ask your audiologist:

  • With this brand’s implant system, is battery life fixed or is it affected by the coding strategy adjustments made to my audio processor?
  • What are the different battery options for each device?
  • What are the pros and cons of each type of battery, for instance rechargeable and disposable?

to find out how battery life affects everyday life.

Future compatibility with upcoming technologies

A sound-coding strategy is the technology in the audio processor that translates an acoustic signal into an electrical stimulus, which the implant delivers to the brain. This results in the perception of speech and music. The better the sound-coding strategy, the more natural speech and music will sound. Some implants have ‘sleeping features’ that can be activated by software or by the audio processor itself, making them compatible with future advances in sound-coding technology. It’s a way of upgrading your implant without surgery.

Ask your audiologist:

  • Will this implant be compatible with upcoming advanced sound coding strategies?
  • How likely is it that I will need to have the implant replaced in future in order to be able to use the newest technology?

to learn about the benefits of future compatibility in everyday life.

Backwards compatibility

If an audio processor is ‘backwards compatible’, it will be compatible with an implant that you may have had for several years. This means that you can take advantage of the most up-to-date audio processor technology, even though your internal implant may use older technology. This is important as you can expect to have the implant for many years, possibly for life, whereas your audio processor will change more often. When choosing a new audio processor, check how many years of backwards compatibility it has.

Ask your audiologist:

  • What’s the backwards compatibility of the audio processor?

to hear about the advantages of backwards compatibility.

MRI compatibility and the Teslas

Magnetic resonance imaging (MRI) scanners use powerful magnets to produce detailed images of a person’s body and are increasingly being used to help diagnose conditions without the need for investigative surgery. Most implants are now ‘MRI compatible’, which means that the magnet doesn’t have to be surgically removed before the scan and put back again afterwards.

However, the level of compatibility varies. A standard strength MRI is 1.5 Teslas (magnetic units) but increasingly more powerful scanners up to 3.0 Teslas are being used. The higher the Tesla, the more detailed the images. This is important for diagnosing conditions such as brain tumours. With the continuing trend towards higher strength MRIs, the level of implant compatibility is an important long-term decision.

If an implant is not compatible to the correct MRI strength, the magnet would have to be surgically removed before the scan and then put back afterwards. This is a simple outpatient procedure but is inconvenient because you won’t be able to wear your audio processor – and so won’t be able to hear – until the wound has healed.

Problems that could occur if the magnet of an incompatible implant is not removed include blurred images, demagnetisation and dislocation of the magnet.

Ask your audiologist:

  • To how many Teslas is my implant MRI compatible?
  • In what circumstances would a 3.0 Tesla MRI be needed?
  • What happens if I need a high-resolution MRI scan and my implant isn’t sufficiently compatible?
  • If I need to have the magnet removed, what will this involve and how long will it take before I can use my audio processor again after the magnet has been replaced?

to discuss MRI compatibility in more detail.

Electrode design

During the operation, an electrode is implanted into your cochlea in your inner ear. The electrode contacts stimulate the nerve cells that are found along the length of your cochlea and respond to different sounds, from low to high frequencies. To hear the full range of sound, you’ll need an electrode that’s long enough to cover your whole cochlea. As the length of the cochlea varies between individuals, check that the system you choose offers a variety of electrode lengths so the surgeon can select the one that fits your cochlea best and will deliver the best results for you.

Electrode flexibility

The softer and more flexible the electrode, the more ‘atraumatic’ it is. This means there’s a low risk that it will cause trauma, or damage, to the delicate structure of your inner ear, helping to protect your remaining natural hearing, often referred to as ‘residual hearing’.

The surgical technique used is also important when it comes to preserving residual hearing. It’s important to preserve the nerve structures inside your cochlea to maximise your chances of benefiting from future therapies and technologies.

Some electrodes are pre-shaped, which makes them easier for the surgeon to insert but less flexible. Also, if an electrode has a lot of electrode contacts that are close together, it will tend to be stiffer than one with contacts that are spaced out. Another potential problem with electrode contacts being close together is that they may interact, “cross talk”, thereby negatively affecting sound quality.

Ask your audiologist:

  • How much cochlear coverage will the different electrode options give me?
  • Which electrode is the softest and most flexible?
  • Which electrode will best preserve my residual hearing?
  • Can I see what the different electrodes look like?
  • Do you use surgical techniques designed to avoid trauma and preserve residual hearing?

  to discuss the different electrode options.

Sound management / intelligent sound adaptation

Sound management/intelligent sound adaptation

All audio processors have different settings that can be adjusted according to the listening environment you’re in, whether it’s a quiet room, a concert hall or a noisy restaurant. You can adjust these manually, using a remote control, in the same way that you can adjust the volume on a TV set. However, increasingly devices are able to automatically detect a change in environment and adjust the sound program so you don’t have to keep fiddling with buttons.

Ask your audiologist:

  • How many programs do the different audio processors have?
  • Which audio processors adjust sound automatically?
  • What are the pros and cons of the different sound management systems?

 to learn about the benefits of sound management in everyday life.



You can wear it while showering or swimming. In most cases, it’s not the audio processor itself that’s waterproof, but the accessories you can add as required, which will allow you to fully submerge.

Ask your audiologist:

  • Can I wear my audio processor while showering or swimming?
  • Does it have waterproof accessories?
  • Is there a time limit as to how long the audio processor can safely stay in the water?
  • Does the audio processor have a depth limit?
  • Is the internal implant safe for scuba diving and to what depth is it guaranteed to withstand water pressure?
  • Does the company’s warranty cover water damage and if so in what circumstances?
  • How long will my batteries last with the waterproof accessory on?
  • Is it possible to hear with the waterproof accessory on?

 to discuss the different water-resistant and waterproof options.


The device is protected against sweat, rain, humidity and the odd splash but should not be submerged in water, or worn for showering or swimming.

Data logging

This feature keeps a complete record of how you use your device on a day-to-day basis, for instance how much time you spend in noisy or quiet environments and how often volume and other settings are changed. This shows your clinician how to make the right adjustments to your device for your specific needs, and how to adapt your rehabilitation programme to get the optimum results.

Connect with a HearPeers mentor

to discuss the design features of cochlear implants in more detail.