Modern hearing aids.
What can I expect from the latest generation of hearing aids?
Modern hearing systems are tiny, high-performance computers. Thanks to their sophisticated technology and wireless connectivity to other devices, they significantly improve quality of life. Here you can find out about the useful and smart functions you can expect from a modern hearing aid, as well as the fantastic possibilities hearing aids will offer in the near future.
No comparison to the previous systems
For decades, hearing aids were mere amplifiers. They paid little attention to the individual characteristics of hearing loss or the needs of the wearer. In addition, they tended to produce feedback, were clunky and unsightly.
All this has now been a thing of the past for several years. Modern hearing aids are miracles of digital technology in terms of their shape and size, and are almost or completely invisible when worn. They can be adjusted individually to suit the needs of the wearer’s hearing loss, and they have automatic programs for any environment. This means, for example, that loud background noise is muted while voices are amplified. What’s more, with Bluetooth they can transmit sound directly from other devices such as smartphones, smartwatches or TVs. In this way, they’re becoming the ultra-modern wearable* or hearable** device.
All of these achievements make everyday life much easier for people with hearing loss. The result is a significantly improved quality of life.
Did you know?
Modern hearing aids have a significantly longer battery life than those of just a few years ago, thanks to optimized, energy-saving technology. Find out more on the topic How does a hearing aid work?
Structure of a modern hearing aid
All hearing aids essentially have a similar structure: They have one or two microphones, an amplifier and a speaker. The operating principle is simple: The microphones pick up background noise. The sound is converted into electronic impulses and processed. The signals – which are amplified and modulated as necessary – are then converted back into sound and forwarded to the ear. This principle is the same for all modern hearing aids. However, there are crucial development differences, i.e. the quality of the processing and electronics, functionality of the programs, connection possibilities and so on.
The heart of the modern hearing aid: a tiny computer
Modern hearing aids are smart wearables (or to be more precise, hearables), which work using digital technology. This opens up a whole new set of possibilities: the sound signal is – after accurate adjustment by a hearing care professional – modified so that it best offsets individual hearing loss. And with the help of sophisticated control and filter programs, modern hearing aids continually optimize amplified sounds by accurately adapting to the current listening situation.
The required processing power is provided by a tiny but extremely powerful computer. The computer in a modern hearing aid can perform over 550 million calculations per second. This is comparable to the performance of a fully-fledged office computer.
“Smart hearing aids” – What are they?
In this context, “smart” means that these electronic devices connect wirelessly and exchange information with each other (usually via Bluetooth or radio). So-called “smart hearing aids” can therefore wirelessly connect to mobile phones, smartwatches, TVs or MP3 players. This makes them the most modern wearables or to be more precise, hearables. The really ingenious thing is that the voice of the other person on the phone, music, podcasts, or sounds from the TV are streamed directly into the hearing aid. This is a real milestone.
All background and static noise is faded out and the sound is transmitted crystal clear, directly into your ears. For hearing aid wearers, this is a real step forward.
Along with improved sound quality, wireless connectivity with smartphones presents even more advantages: The hearing aid settings are easily and conveniently controlled via an app on your smartphone or smartwatch. What’s more, the hearing care professional looking after you can access the hearing aid directly and wirelessly during your consultation.
360-degree sound localization
Spatial hearing has always been vital to human survival. Our Stone Age ancestors needed it to hunt, but also to be warned in case of approaching danger (such as predators). Even in our modern world, we depend on directional hearing on a daily basis. For example, this applies when trying to pick out the right sounds from the jumble of noised and voices around us – or to locate an approaching tram from behind in time.
This was a major problem with hearing aids, until recently as even those who wore two hearing aids largely lost out on natural three-dimensional hearing.
This is because each device was set individually for the ear in question, but the sound profiles for both ears were not synchronized.
The new generation of digital hearing aids now ensures that the hearing aids communicate with each other in both ears. With the aid of electronics, spatial sound orientation (known as 3D hearing) has been restored. This is not only safety-related; the wearers of such models receive a lot more listening pleasure than before, despite their hearing loss.
Rechargeable hearing aids
At the heart of modern hearing aids lies a tiny, high-performance computer that runs 24/7. This comes at a price: such hearing aids require a relatively high amount of energy. Tiny but powerful hearing aid batteries, called button cells, provide this energy. The disadvantage of them is that they need to be replaced at regular intervals. How long they last depends on a number of factors, including amplifier performance and battery type. If the hearing aids are often wirelessly connected to a smartphone or TV, energy consumption increases significantly.
Therefore as a rule, hearing aid batteries must be replaced after five to fourteen days. This is what many wearers find annoying, mainly because dexterity decreases with age, making it difficult to replace these tiny batteries. You also have to always remember to carry spare batteries with you, especially when traveling. So why not charge hearing aids just as easily as electric toothbrushes or smartphones?
Lithium-ion batteries in hearing aids
The latest hearing aid generation with lithium-ion batteries makes this possible. Once charged, such hearing aids provide up to 24 hours of listening pleasure. The wearer’s daily routine is quite simple: At bedtime, the hearing aids go in the charging station – done. After just three hours, the hearing aids are ready for use again.
Incidentally, lithium-ion batteries in hearing aids also protect the environment. This is because normally everyone who wears hearing aids in both ears will accumulate around 100 (!) zinc-air batteries a year that need to be disposed of.
Anything but science fiction: what hearing aids will soon be able to do
The hearing care specialist places a membrane on the eardrum, similar to a contact lens on the eye. This is then stimulated with laser light pulses emitted by the hearing aid. The movement of the lens is transmitted directly to the eardrum. The advantage of hearing lenses is that they cover a much wider hearing spectrum than the speakers in conventional hearing aids.
Battery-free hearing aids
The biggest problem with implanted hearing aids today is that wearers have to change the battery. Several research groups around the world are therefore currently working on implanted hearing aids that no longer obtain their energy from a battery, but from the human body.
German researchers are working on a hearing aid that can read the thoughts of the wearer, and consequently adapt dynamically to his/her hearing intentions. One such scenario may involve, for example, listening to two different discussions which are taking place in a larger group. For this purpose, the researchers are developing an attention-controlled brain-computer interface that controls directional microphones in the hearing aids, depending on the direction of the wearer’s head or even gaze.
The ear is an ideal, protected location to place sensors. Some future hearing aids will therefore be equipped with different signal transmitters, both to optimize the hearing aid sound (sensors for EEG signals) and to monitor the general health of the wearer, for example by measuring his/her blood sugar level or blood pressure.
Hearing aids that can lip read
Researchers in the UK and Switzerland are currently working on a hearing aid that can also lip read, in addition to the standard hearing aid function. In concrete terms, a miniature camera worn on glasses or on a necklace picks up the other person’s mouth movements and turns them into auditory signals. This is a great help, especially in noisy environments.
Interpreter in the ear
As so-called wearables and/or hearables, hearing aids will also be appealing to people with intact hearing in the future – not just for listening to music and phone calls discreetly in your ear, but also for navigating or even interpreting real-time spoken texts – like the famous “Babel fish” earpiece from science fiction classic, The Hitchhiker's Guide to the Galaxy.
Full restoration of hearing
Will hearing aids become redundant one day thanks to medical advances? This is hardly conceivable from today’s perspective. Nevertheless, research groups in the UK and US are working on a method that will regenerate damaged or dead hair cells in the cochlea with the help of stem cells. Experiments with deaf gerbils, have already achieved the first positive results.
*Wearables: Small, networked computers that can be worn on the body to support the wearer in everyday life. Some examples include Fitness trackers and smartwatches.
**Hearables: Earphones with additional functions, e.g. wireless connectivity to smartphones, sensors for medical monitoring and activity trackers.