While hearing aids and other amplification solutions work well for many people, not all ears are able to receive benefit from hearing aids. These so-called ‘unaidable ears’ often have little to no hearing abilities, very poor thresholds or weak speech discrimination abilities- sometimes people are born with one ‘dead ear’, and sometimes the nerve of one ear can be damage irreparably by illness or trauma. For those people with one normal hearing or aidable ear, and one unaidable ear, audiologists often consider a CROS or BiCROS system.
A CROS (Contralateral Routing Of Signals) system involves putting a microphone on the unaidable ear which transmits the sound from that side into the good ear on the other side. It allows the stronger ear to receive sound for both sides. When this system is used on a person with some hearing loss on the better side as well, it is called a BiCROS system- meaning that the sound is being picked up on both sides and both signals are being sent and amplified into the good ear. These systems make use of wireless technology to transmit and receive sound from one device to the other, both devices looking just like modern hearing aids.
In an expansion to their Nx platform, Signia* has just released their CROS Pure 312 Nx, which is optimised to work with their Pure 312 Nx hearing aid on the good ear. When paired in this way, it allows the wearer with one normal hearing ear, or with only one aidable ear, to benefit from the many binaural features present in today’s modern hearing aids, including Own Voice Processing, which normalises the sound of one’s own voice, and narrow beam directionality, which can help to improve speech understanding in background noise. These binaural features were not present in previous CROS systems.
The CROS Pure 312 Nx is small and cosmetically attractive, the same size as the Pure 312 Nx, so when paired together they look symmetrical and use the same sized battery. Our patient responses have been good so far, with one patient reporting hearing better on the ‘bad’ side than on the good side in background noise, and another even feeling as though there was sound coming into the poorer ear (unfortunately not the reality but rather a clever trick of the brain). We look forward to seeing how these patients do with their CROS systems in the future.
For the past few years there have been a range of different CROS devices available from different hearing aid brands, and the selection of the specific model for an individual should always be done in consultation with a qualified audiologist who works with a range of hearing aid suppliers. If you would like more information about CROS or BiCROS systems, please comment below, or contact us.
*Please note that Francis Slabber and Associates has no direct affiliation with Signia, Sivantos, or any other hearing aid brand, and all opinions shared are done so without any compensation by the supplier, nor benefit to the practice or patients involved. Francis Slabber and Associates is an autonomous practice and our audiologists fit a variety of brands and products without prejudice.