CROS and BiCROS Hearing Aids for Single Sided Deafness

Single-sided deafness (SSD) is a type of hearing loss in which there is normal hearing in one ear, and severely impaired or no hearing in the other ear. Patients with single-sided deafness find it difficult to localize sound, hear conversation from their impaired side, and discriminate speech in the presence of background noise.

If you’re struggling with SSD you may be considering purchasing a hearing aid; but what if the hearing loss on your impaired ear is so profound that you simply won’t benefit from a hearing aid? In this case, you might want to consider wearing a special kind of hearing aid which can capture sound from your “bad” ear, and send it to your normal ear. There are two types of hearing aids that are able to do this, CROS and BiCROS hearing aids. For those who are interested, CROS is an acronym for contralateral routing of signal.

CROS vs. BiCROS: Which is for you?

CROS and BiCROS hearing aids are very similar in functionality, with one slight difference.

CROS: If you have no hearing in one ear, and normal hearing in the other, a CROS might be right for you. With a CROS system, you’ll wear a microphone on your deaf ear, which will capture sounds from that side and transmit them to a hearing aid worn on your normal ear. That hearing aid will then output those sounds (without amplification), into your normal hearing ear. In this way, you’re able to hear sounds from your “bad side,” in your good ear.

BiCROS: If you have no hearing in one ear, and a hearing loss in the other, a BiCROS might be right for you. A BiCROS system works exactly like a CROS system, with one small difference. With a BiCROS system, the hearing aid worn on your better ear will have the microphones turned on, so it will amplify sounds for your better ear. So with a BiCROS, you are able to hear sounds not only from your bad side, but also amplified sounds from your better ear’s side.

Here’s an image courtesy of Phonak which better illustrates the difference between CROS and BiCROS hearing aids.

What are the main advantages and disadvantages of CROS and BiCROS hearing aids?

The main advantages of CROS technology are:

• Sounds from your deaf side are not “lost”, and the head-shadow effect is reduced.
• The ability to localize sounds (tell where they are coming from), is improved.

The main disadvantages of CROS technology are:

• Sometimes, the extra sound from the bad side may actually interfere with your ability to hear clearly from your good ear. This is exacerbated in noisy situations.
• Because CROS hearing aids use an internal antennae to communicate with each other, the batteries are drained quickly. The battery life of CROS hearing aids is usually very short, 2-3 days. For this reason, it’s a good idea to consider a CROS device with a larger, size 13 battery.

Is there a cost difference in buying CROS/BiCROS aids vs. traditional hearing aids?

To answer this, let’s be clear about what CROS and BiCROS systems actually are. In both cases, you have what’s called a “CROS transmitter” on your deaf ear. The CROS transmitter looks just like a typical hearing aid, but it’s not. It has a microphone in it to capture sounds, and then transmits those sounds to the other aid. So the transmitter is not a fully capable hearing aid. For this reason, the transmitter is often times sold at a lower price than the opposing aid. However, this isn’t always the case, as all hearing providers set their own pricing policies.

Opposing the transmitter, is the hearing aid on the better ear. Whether you have a CROS or BiCROS setup, this hearing aid is always a fully capable hearing aid, and so will be priced accordingly.Please note that whether you use a CROS or BiCROS system, you will purchase what is called a CROS transmitter. Your hearing provider will then apply programming to your devices, and that’s when your system will be designated as either CROS or BiCROS.