Single Sided Deafness Solutions | CROS/BiCROS/BAHA Hearing Aids

Do you experience hearing loss in only one ear? If so, a traditional hearing aid may not be your best option. At my clinic, I constantly see individuals with a single-sided hearing loss issue using traditional hearing aids, even though their hearing loss will not receive benefit from it. Individuals who have a single-sided hearing loss are presented with a unique set of challenges, particularly if that hearing loss is so severe that it prevents benefit from a traditional hearing aid.

While some cases of single-sided hearing loss or unilateral hearing loss can receive benefit from traditional hearing aids, there are cases of single-sided hearing loss so severe that even when you put a hearing aid on the good side, it cannot amplify sound to a level that becomes clear to the user. In the case of single-sided deafness, a traditional hearing aid definitely will not work.

Here, we take a look at the treatment options available for single-sided hearing loss.

Challenges with Single-Sided Hearing Loss

Deciding to not treat single-sided hearing loss can come along with a unique set of problems – namely, not being able to hear and understand someone on your poorer side. This problem can be made even worse if you have a hearing loss on your better side, which can compound the hearing difficulty.

If you experience a single-sided hearing loss, you cannot rely solely on your better ear due to the head shadow effect, which is caused by your head blocking sound from one side to the other. The head shadow effect creates a seven-decibel reduction in sound, which is the difference between understanding speech and not even being able to detect it.

Treatment Options for Single-Sided Hearing Loss

There are several treatment options for single-sided hearing loss:

Contralateral Routing of Signal (CROS)

CROS is a good option for individuals who have unusable hearing on their bad side and normal hearing on their good side. The CROS solution uses two devices: a transmitter and a hearing aid. A transmitter is placed on the poor-hearing side ear and transmits sound over to your better ear, which wears the hearing aid. The two devices both look like hearing aids, but one is actually a transmitter and the other is a hearing aid. If you go somewhere like a restaurant and there’s someone sitting on your bad side, their voice will be picked up by the transmitter and you’ll hear them in your good ear, just as if they were sitting next to you on the normal-hearing side!

Bilateral Contralateral Routing of Signal (BiCROS)

BiCROS is great for individuals who have unusable hearing on their bad side and some level of hearing loss on their better side. BiCROS is used to overcome the head shadow effect, and it also compensates for the hearing loss in the better-hearing ear. The setup is exactly the same as the CROS; the only difference is that the hearing aid on the better side (with hearing loss) provides amplification. Like with the CROS system, you’re still receiving sound from the transmitter on the bad side – the only difference is with BiCROS, the hearing aid worn on the better-hearing ear is also amplified.

CROS and BiCROS technology is available from manufacturers such as Signia (otherwise known as Siemens), Starkey, Widex, and Phonak.

Bone Anchored Hearing Aid (BAHA)

BAHA is great for both individuals who have normal hearing on their better side or some level of hearing loss on their better side. This treatment option works by using a sound processor to send vibrations through the skull from the bad hearing side to the normal/ better hearing side, which allows you to hear. The processor sticks to a metal post or a magnet that is implanted into your skull. This sounds worse than it really is, but it allows your cochlea (your hearing organ) to sense the vibrations of sound – and any vibration of the skull from your bad side will also be heard by your normal/better hearing ear. This gives you the effect of being able to hear sound from your bad side in your normal/better hearing ear.

A few companies make BAHA hearing aids, notably Cochlear America and Oticon Medical.

Things to Keep in Mind when Seeking Treatment for Single-Sided Hearing Loss

In terms of performance, there is not a lot of difference between the CROS/BiCROS technology and the BAHA technology. However, if you do have a hearing loss in your better ear, you may not be a candidate for a bone-anchored hearing aid, depending on the severity of that hearing loss.

Overall, treating single-sided hearing loss is not very common for a lot of hearing care professionals. When seeking treatment, make sure you look for a hearing care professional who’s comfortable working with technology for single-sided hearing loss.

It is also important to note that if you do have a single-sided hearing loss issue, your hearing care professional should refer you to an ear, nose, and throat physician to identify if there is a medical cause. In rare cases, single-sided hearing loss could be caused by a tumor that sits on your auditory nerve and blocks sound from that side. If this is the case, the tumor must be monitored or removed.

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