What is a Bi/CROS system Potential benefits and limitations Is it for me?
Single-sided deafness (SSD) refers to a condition where a person has usable hearing in one ear only. The poorer ear does not receive benefit from traditional hearing aids, whilst the better ear may have normal hearing, or a hearing loss. People with SSD may have difficulties in picing upo the direction of sounds, detecting speech on their poorer hearing side, and difficulties hearing in the presence of background noise. Fortunately there are modern solutions to help these patients. One such solution is the CROS/BiCROS system.
What is a Bi/CROS system?
A CROS system is worn when the individual has one ear with unaidable hearing, and one ear with normal hearing. A microphone, worn on the bad ear, picks up the signal and transmits it to a receiver worn on the ear with normal hearing.Figure 1. CROS system (Image - Widex.com)
A BiCROS system is worn when the individual has one ear with unaidable hearing (where a hearing aid won't work), and the other ear has a hearing loss. A microphone, worn on the bad ear, picks up the signal and transmits it to a hearing aid worn on the better hearing ear. The hearing aid then amplifies the signal to a level that the user can hear.
Figure 2. BiCROS System (image - widex.com)
Currently there are a few manufacturers offering wireless BiCROS/CROS solutions: Phonak, Starkey, Widex , Signia (Siemens) and most recently Oticon. While each company utilises their own technologies, the end-goal is the same: to enable the wearer to hear sounds coming from their poorer ear in their better hearing ear. Some brands like Phonak and Signia also have in the canal models available, for those who are concerned about cosmetics.
Potential benefits and limitations
Successful CROS users will find several improvements to their daily communication difficulties. These include an improved ability to hear people when speaking to their poorer ear; an improved ability to hear in background noise (if speech is coming from the poorer side); and better awareness of sounds in the environment. Unlike other SSD solutions, the CROS/BiCROS is easily fit in the audiologists’ office and does not require any surgery. Since the CROS/BiCROS device does not amplify sound to the poorer ear, it is unlikely that users’ will experience a significant improvement in ability to localise sounds. Some clients do however report subjective improvements in localisation ability.
Examples where Cros/BiCros is of benefit are:
- In a car when your poor ear is towards the driver or passenger
- In groups, where people are located on your poorer ear's side
- Walking in traffic, where someone is speaking to you from your poorer side.
- At home, when you aren't facing the speaker and they start speaking from your deaf side.
So gone are the days, where you had to make sure you have people sitting on your "good" side.
It is impotant to note that this system will not reduce tinnitus in your bad ear as there is no direct stimulation to the poorer hearing ear.
NOTE: Wireless CROS/BiCROS systems use a lot of battery power, so hearing aid battery life might only be a few days. Phonak and Signia have hower released rechargeable models, which addresses this issue very effectively, giving full day use before a charge is required.
Is it for me?
Modern CROS/BiCROS devices are suitable for most people with SSD. Potential candidates will have one ear which cannot be aided by traditional hearing aids, and one ear which has good speech understanding at either normal, or elevated volumes. The better hearing ear may have normal hearing, or a hearing loss. It is suitable for those who want to hear more clearly when people are speaking to their poorer ear, and for those who do not wish to have surgery. Another advantage of the CROS is that it is normally much cheaper to get an aid and a CROS than two hearing aids.