CROS and BiCROS fitting
If you are completely deaf, you cannot use a normal hearing aid. A hearing aid only amplifies sound and stimulates the inner ear. However, this is no longer sufficient. If, on the other hand, you can only hear on one side, you can no longer assign sounds and do not know which direction they are coming from. This makes it difficult for you to distinguish background sounds. But even for these cases, there are special solutions that make it easier for you to hear. These solutions are individually tailored to your needs.
This guidebook deals with the so-called CROS and BiCROS fitting technology for your ears. This technology is used if you are deaf on one side. It enables you to continue to hear directionally. Your quality of life improves effectively as a result.
Directional hearing despite unilateral hearing loss
CROS and BiCROS hearing aids enable you to hear spatially and directionally, respectively, despite unilateral deafness. If you hear with two healthy ears, i.e. binaurally, then the sound waves reach your hearing with different strengths. The sound waves simply take longer to reach the averted ear and arrive there more quietly. The brain uses this information to pinpoint the origin of the sound. This allows your brain to pinpoint exactly which direction the sound is coming from. You can therefore orient yourself well in the room. Localization is then no problem, because the exact position is easily heard.
If you are now unilaterally deaf, then you can always hear noises, sounds and voices only with the healthy ear. In this way, the direction of the sound or the location of the sound source is faked to the brain, so to speak. Turning your head or changing your position will not help. With unilateral deafness, the ears and brain are not able to recognize the direction from which the sound sources are coming.
For you as an affected person, it is very difficult to recognize a specific sound among many diffuse and loud background noises and to concentrate on it. Even conversations then become a problem for you.
There can be different causes for unilateral deafness:
- Craniocerebral trauma
- Congenital impairment
If you are deaf on one side, a CROS or BiCROS fitting can enable you to hear direction again. You will then recognize when you are spoken to on the damaged side, for example. CROS/BiCROS technology is highly sophisticated. It redirects the sounds that you cannot actually hear to the hearing ear. This allows precise processing to take place in your brain. So your life is made much easier with CROS and BiCROS hearing aids.
How do CROS BiCROS hearing aids work?
In a traditional hearing aid, the receiver and microphone are close together. This amplifies the signal at the corresponding ear. However, in the case of unilateral deafness, this technique does not lead to success. That is why scientists have developed a completely different concept. In the so-called CROS fitting, the receiver and microphone are placed independently of each other in different locations.
On the deaf ear, a microphone picks up the sound and automatically transmits it to the healthy ear. This is where the receiver is located. The normal hearing of your healthy ear is not affected by this technology, but the brain can thereby assign from which direction the sound waves come.
A few years ago, the technology required for this had to be hidden in a spectacle frame. The microphone was attached to the temple of the glasses and the cable for transmitting the sound was incorporated into the frame.
In the meantime, the process has become very modern and the hardware very inconspicuous. The transmission takes place entirely without cables via radio signal. The sound is transmitted quickly and precisely and arrives in the functioning ear by means of an earmold. Earmolds are hearing pieces that are individually fitted. To do this, you first have our hearing care professional take an impression of your ear. This then serves as the basis for the production of your earmold, which fits perfectly in your ear canal after the fitting.
The technical features of CROS hearing aids can vary from manufacturer to manufacturer. Here, too, there are both behind-the-ear and in-the-ear hearing aids.