In Belgium, hundreds of deaf and hard of hearing receive each year a cochlear implant, in which a surgeon inserts a number of tiny electrodes into a part of the inner ear: the cochlea or cochlea. After surgery, the audiologist must properly adjust the device. To do this, the user must listen to the sounds and judge their sound. Depending on the answers, the audiologist can adjust the settings. However, this process takes a lot of time and effort, especially for people who can’t explain how well and what they hear: just think of young children, people with a mental disability, or older people with dementia. An additional issue is that you have to reset every few years or even every few months to update everything. Hearing loss and personal preferences can both change over time.
An audiologist often estimates your hearing based on how well you can judge sounds. This process takes a lot of time and effort in young children.
use your brain
We can prepare cochlear implants more efficiently if we can estimate someone’s hearing without them the right person for her To give a verbal response. During my PhD research, we found a solution to this: using the brain. After all, brains produce electrical signals all the time when they process information such as sound. The properties of these brain waves change depending on the sounds you hear and how well you are able to hear them. For example, we know that a brain wave that rises and falls according to the rhythm of syllables and words is generated when listening to the speaker. If the speaker is less clear, the fluctuations of this brain wave will be smaller and slower.
Thus, brainwaves are very useful for hearing estimation, and can be used to automatically check the settings of a hearing implant. When listening to a poorly set up speaker, certain brain waves will indicate that a sound is heard, while other brain waves will reveal that the message does not come clearly at the end. So in our brains there is a big difference between hearing and understanding the speaker. We’ve shown for the first time that the beneficial brainwaves that make speech comprehension are also present in people who hear with a cochlear implant.
By looking at specific brain waves, we can estimate how well individuals and even children process the speech sounds they hear in their brains.
How do you measure brain wave?
However, measuring brain waves is not yet practical. To get a reliable measurement, you have to go to the hospital, where an expensive machine with many cables and sensors is placed on your head. So while this solution is a huge improvement for young children or those with communication difficulties, it costs a lot of time, effort and money for the average cochlear implant user who can tell how good the sound is.
Do these brainwaves have limited applicability in audiology? of course no! With a second breakthrough, we’ve developed a technology to measure brain waves with electronic components already in the implant itself. Not all of the implant’s electrodes in the cochlea act simultaneously, so they can be used in the “free” moments to absorb brain activity. So they have a second rotating function as a sensor. This way we no longer need external equipment and cables. This measurement technology makes the use of brain waves for all cochlear implant users more practical and efficient.
cochlear implant electrodesleft) can also be used Used to measure brain waves. The electrodes are at the end of the cables. The outer (right) part contains a small computer in which all settings are stored.
If we put together the technological building blocks we have developed, we can think of new applications and improvements for existing hearing implants. In the first step, a person with an implant that can measure brain waves does not have to come to the hospital very often: audiometry can be measured automatically and objectively in everyday life. An important advantage is that hearing is then assessed in realistic listening environments where the user is most often, such as at school, at home in front of the televisionAnd Or at a family celebration. The audiologist can then view this data remotely and step in to adjust the device as necessary.
If we take it one step further, it will be possible in the future to design smart, self-guided cochlear implants. Such a system can measure how well the user can hear with the help of brain waves, after which he will be able to adjust himself independently. In my research, we have developed technology that allows the device to “measure and know”. You can compare that to a self-driving car, which needs cameras and distance sensors to gather information. The next challenge is to develop an AI that effectively makes the decision to make adjustments. User safety is paramount here of course.
Although we paved the way, it may be another ten years before the first people with smart hearing implants are around. I am already looking forward to the future in which every person with a hearing impairment who would like it can hear well again at any time, with settings tailored to their needs, completely automatically and without the need for a regular hospital visit.
Ben Somers IHe was nominated for the Flemish PhD Cup. Find out more about his research at www.phdcup.be.
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