Living with hearing loss in just one ear can be more difficult than most people realize. When you can’t hear from one side, it can feel like half the world is muted. Whether it’s trying to follow conversations in noisy environments or missing out on soft sounds on your deaf side, single-sided hearing loss affects not just what you hear, but how you connect.
CROS and BiCROS hearing aids are specifically designed to help with this type of hearing loss. They don't restore hearing to the affected ear, but they do offer an intelligent workaround that can make day-to-day life much easier. This article explores what these devices are, how they work, and whether they might be the right solution for you.
Key Takeaways
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CROS hearing aids transfer sound from the non-hearing ear to the better-hearing ear.
BiCROS systems also provide amplification for users who have some hearing loss in their better ear.
These hearing aids can improve communication, especially in noisy environments, but they take some time to get used to.
What Are CROS and BiCROS Hearing Aids?
CROS stands for Contralateral Routing of Signals. These hearing aids are designed for people who have little to no hearing in one ear but normal hearing in the other. BiCROS systems are very similar, but they also provide amplification in the better ear, which may have some hearing loss.
The basic concept is simple: a microphone on the ear with poor or no hearing picks up sound and wirelessly transmits it to a hearing aid on the other ear. This helps users hear sounds that would otherwise be lost due to the "head shadow" effect, where the head blocks high-frequency sounds from reaching the good ear. This natural barrier can create challenges when listening in group settings or in public spaces with background noise.
CROS Hearing Aids
CROS hearing aids are ideal for people with single-sided deafness (SSD) and no measurable hearing in one ear. They allow wearers to detect sounds from all directions without having to constantly turn their head.
In a CROS setup, the system typically involves two devices:
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A microphone placed on the deaf ear that picks up sound from that side
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A receiver worn on the better-hearing ear that plays the transmitted sound
This setup allows you to perceive sounds from the environment more naturally. For example, if someone speaks to your deaf side, you'll hear them through your functioning ear as if they were on that side. It doesn't bring back stereo hearing, but it does improve environmental awareness and ease of conversation. Many users find that it helps them better participate in meetings, social events, and one-on-one interactions.
BiCROS Hearing Aids
A BiCROS system is used when the ear that can still hear has some degree of hearing loss. It combines the benefits of a traditional hearing aid and a CROS system in one.
In this case, the hearing aid on the better-hearing ear not only receives the sound from the poorer ear, but also amplifies the sound entering that side. This dual functionality is especially useful for individuals who struggle with hearing on both sides, but to different degrees.
Here’s how a BiCROS works:
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The device on the poor-hearing ear picks up sound and sends it to the better ear
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The receiver on the better ear amplifies both the transmitted sound and local sound
BiCROS can be particularly helpful in noisy environments, where even the better-hearing ear might struggle without amplification.
Who Are CROS and BiCROS For?
These systems are not meant for everyone with hearing loss. They are specifically designed for people who:
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Have unilateral hearing loss (hearing loss in only one ear)
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Have no usable hearing in one ear
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Have either normal or some hearing loss in the other ear
Common causes include:
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Sudden sensorineural hearing loss that doesn’t recover
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Acoustic neuroma (benign tumor affecting the hearing nerve)
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Ménière’s disease, which causes inner ear fluid imbalances
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Physical head trauma
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Viral or bacterial infections impacting hearing
Understanding the root cause of hearing loss is crucial. For sudden loss, prompt treatment—such as steroids—may restore some function. But in cases where hearing does not return, CROS or BiCROS can be a practical next step. An audiologist or ENT can help determine your eligibility and recommend the right path.
Pros and Cons of CROS and BiCROS Hearing Aids
Like any hearing solution, CROS and BiCROS systems come with their advantages and limitations. While they offer meaningful benefits, it’s important to set realistic expectations.
Benefits
Wearing CROS or BiCROS hearing aids can bring several improvements to your daily life. These systems:
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Allow you to hear sounds from both sides, reducing listening fatigue
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Improve your ability to engage in group conversations
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Increase situational awareness, especially in public or crowded places
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Minimize the need to turn your head constantly to hear better
Over time, many users report feeling more confident and less isolated during everyday interactions.
Limitations
Despite the benefits, CROS and BiCROS systems are not without their challenges:
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They do not restore stereo hearing or true sound localization
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Background noise can still be distracting or overwhelming
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Getting used to rerouted sound can take several weeks
If you're trying these hearing aids for the first time, patience is key. Working with an audiologist to fine-tune settings can also help ease the transition.
Other Options for Single-Sided Hearing Loss
If you’re not a good candidate for CROS or BiCROS, or if you don’t adjust well to the technology, other options are available. These include surgical and non-surgical alternatives.
Bone-Anchored Hearing Systems (BAHS)
BAHS devices bypass the outer and middle ear by transmitting sound vibrations through the bone directly to the inner ear. This makes them a good option for people with chronic ear infections or structural abnormalities. These devices typically require minor surgery to implant a small post into the skull, which anchors the external processor.
Cochlear Implants
While not always the first option for single-sided hearing loss, cochlear implants may be used in cases where both conventional hearing aids and BAHS are ineffective. These devices stimulate the auditory nerve directly and are typically reserved for severe cases. As with any surgical solution, evaluation and medical screening are required.
What to Expect When Using CROS or BiCROS
Adjusting to rerouted sound takes time, and some users may initially find it disorienting. However, with full-time use and proper support, most people adapt well and experience significant improvements in communication.
Here’s how to make the adjustment smoother:
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Commit to daily wear, ideally 8–10 hours during waking hours
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Follow up with your audiologist to fine-tune the settings
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Practice in quiet environments first before using the device in noisy spaces
Everyone’s adjustment timeline is different. With consistency and support, the hearing experience becomes more intuitive.
Are CROS or BiCROS Hearing Aids Right for You?
Choosing the right hearing solution depends on your hearing profile, lifestyle, and comfort with new technology. If you have hearing in only one ear and feel like you're missing part of the conversation, it may be time to explore your options.
Take the first step by completing a quick hearing survey to find out if CROS or BiCROS hearing aids could help you hear more naturally again. Take the free hearing survey here.
Find the Hearing Aid That's Right For You
Frequently Asked Questions
What is the difference between CROS and BiCROS hearing aids? CROS aids transfer sound from the deaf ear to a normal-hearing ear. BiCROS aids do the same, but also amplify sound in the better ear if it has some hearing loss.
Will CROS hearing aids restore my hearing on the deaf side? No. These systems do not restore hearing but reroute sound to the functioning ear so you don’t miss out on conversation from that side.
How long does it take to get used to a CROS hearing aid? Most users need at least a few weeks of consistent, daily wear to adjust. The key is to wear them full-time during waking hours to help your brain adapt.
Can I localize sound with CROS or BiCROS hearing aids? Unfortunately, no. While they improve sound awareness, they do not fully restore your ability to tell where a sound is coming from.
Are CROS and BiCROS hearing aids covered by insurance? Coverage varies. Some insurance plans offer partial or full coverage, but it's best to check with your provider and audiologist for details.
