Single Sided Deafness and the CROS/BiCROS Hearing System

The majority of individuals with age related or genetic hearing loss have hearing loss that is in both ears and very similar between ears (symmetric).  The person’s ability to understand speech is usually also symmetric between ears with scores in the 700-100% range in both ears.  Traditional hearing devices are typically the best option for these patients. However, some people have hearing loss that is not the same between ears (asymmetric) or the ability to understand speech is much poorer in one ear.  These individuals often struggle to determine where sounds are coming from and hear in background noise.  They often have difficulty hearing someone approach or speak to them from their poorer ear/side.  And they often receive limited benefit in understanding speech with the poorer ear.  For these individuals traditional hearing devices are often not the best approach.  Below we will discuss the CROS and BiCROS hearing systems for patients with Single Sided Deafness (SSD) or asymmetric speech understanding.

CROS Hearing System

The CROS hearing system is designed for patients who have normal hearing in their better ear and either a “dead” ear without measurable hearing, a profound hearing loss or very poor speech understanding in the affected ear.  Essentially the damage to the affected ear leaves the ear non-functional in that fitting a traditional hearing deice on the ear will not improve the individual’s ability to understand speech. The solution is a traditional hearing device worn on the normal hearing ear and a microphone (which will look the same as the hearing device) worn on the non-functional ear.  The microphone picks up sound from the poor ear and transmits the sound to the hearing device on the normal ear, delivering clear sound to the better ear.  This option allows patients to pick up and understand sound from their “bad” side.  Localization and hearing in noise are usually still difficult, however the patient can now hear someone approach or speak to them from their poorer side.

BiCROS Hearing System

The Bi-CROS hearing system is designed for patients with hearing loss in the better ear that is not as significant and has better speech understanding.  Their poorer ear meets the same qualifications as discussed above in the CROS system section.  The setup is the same, the difference is that the hearing device placed on the better ear actually provides amplification to the better ear which is needed to correct the patient’s hearing loss. As with all hearing devices, the best course of action is to contact your local Audiologist to discuss your specific hearing loss.  An updated hearing evaluation may be necessary to provide the most accurate recommendation for treatment of your hearing loss. Do you know someone that suffers with one-sided hearing loss? Comment below to tell us your experiences!