Single-sided hearing loss (SSHL) can present unique challenges for those affected. One common cause of SSHL is an acoustic neuroma (vestibular Schwannoma), a benign tumour that develops on the vestibulocochlear nerve. The pressure on the nerve from the tumour may cause hearing loss and imbalance. Fortunately, advancements in hearing aid technology, specifically CROS (Contralateral Routing of Signal) and BiCROS systems, offer effective solutions for managing SSHL.

What are CROS and BiCROS Hearing Aids?

CROS Hearing Aids: The CROS system is designed for individuals with one ear that has normal hearing and one ear that has little to no usable hearing. It consists of two devices: one placed on the ear with normal hearing and another on the ear with hearing loss. The device on the impaired ear captures sound and wirelessly transmits it to the device on the normal ear, allowing the user to hear sounds from both sides.
BiCROS Hearing Aids: The BiCROS system is used for individuals who have hearing loss in both ears, but with one ear significantly worse than the other. Like the CROS system, it has a transmitter on the more impaired ear, which sends sound to the hearing aid on the better hearing ear. However, the better ear also has its own hearing aid functionality, amplifying the sound to accommodate its hearing loss.

How do CROS and BiCROS hearing aids work?

Sound Capture: The device on the impaired ear picks up sounds from that side using its microphones.
Sound Transmission: These sounds are then wirelessly transmitted to the hearing aid on the better ear.
Sound Processing: In a BiCROS system, the hearing aid on the better ear also processes and amplifies sounds directly entering it, ensuring balanced hearing from both sides.
Sound Output: The processed sound is delivered to the ear with normal or better hearing, allowing the user to perceive sounds from both sides.

There are several types of CROS and BiCROS hearing aids available on the market, including:

Behind-the-Ear (BTE) CROS and BiCROS: These hearing aids have a microphone and processor unit that sits behind the ear. The most prevalent CROS and BiCROS aids are BTE hearing aids, which are typically available through the NHS.
Receiver-in-the-Ear (RITE) CROS and BiCROS: These hearing aids have a microphone and processor unit that sits behind the ear, with a thin wire connecting to a receiver (speaker) inside the ear canal. RITE CROS and BiCROS hearing aids are discreet and provide natural sound quality. Pocket Hearing currently offers the Pure Charge&Go CROS AX and the Styletto CROS AX RITE models.
In-the-Ear (ITE) CROS and BiCROS: These hearing aids are custom-made to fit inside the ear canal, with the microphone and processor unit sitting within the ear. ITE CROS and BiCROS hearing aids are more discreet than BTE versions and provide a comfortable fit.
Completely-in-the-Canal (CIC) CROS and BiCROS: The only CROS and BiCROS hearing aids that are made to fit deep inside the ear canal are the Signia Silks. They are almost invisible. CIC CROS and BiCROS aids are the most discreet option and offer excellent sound quality. Pocket Hearing is proud to supply the Silk CROS X and the Silk CROS iX models.

CROS and BiCROS hearing aids offer several advantages for those with unilateral hearing loss, including:

1. Improved speech understanding: With CROS and BiCROS hearing aids, users can better understand speech coming from their non-hearing side, making conversations more comfortable and enjoyable.

2. Elimination of the "head shadow" effect: The “head shadow” effect occurs when the head obstructs sound waves, making it difficult to hear sounds coming from the non-hearing side. CROS and BiCROS hearing aids help eliminate this issue by routing sound from the non-hearing side to the hearing ear.

3. Enhanced spatial awareness: CROS and BiCROS hearing aids improve spatial awareness by providing sound input from both sides, allowing users to better navigate their surroundings and detect potential hazards.

4. Increased confidence in social situations: By improving speech understanding and spatial awareness, CROS and BiCROS hearing aids can boost users' confidence in social situations, making it easier to engage in conversations and enjoy group activities.

5. Greater comfort in noisy environments: CROS and BiCROS hearing aids can help users distinguish speech from background noise, making it easier to communicate in noisy environments like restaurants or busy streets.

While CROS and BiCROS hearing aids offer numerous benefits, there are some limitations to consider:

Difficulty localising sounds: Although CROS and BiCROS hearing aids can improve spatial awareness, users may still have difficulty determining the precise location of sounds due to the nature of the microphone's sound pickup.
Limited battery life: As with all hearing aids, CROS and BiCROS hearing aids require regular battery replacement or recharging, which can be inconvenient for some users.
Potential discomfort: Although modern hearing aids are designed for comfort, some users may find certain styles uncomfortable, especially if they are not accustomed to wearing hearing aids.
Cost: Private CROS and BiCROS hearing aids can be expensive, especially for custom-made devices like ITE, and CIC models. However, BTE versions are usually provided by the NHS.

When you start using CROS or BiCROS hearing aids, it's essential to give yourself time to adjust. Here are some tips to help you adapt to your new hearing aids:

1. Start slowly: Begin by wearing your hearing aids for short periods, gradually increasing the duration as you become more comfortable.

2. Practice in different environments: Use your hearing aids in various settings, from quiet rooms to noisy public spaces, to help you become accustomed to different sound levels.

3. Engage in conversation: Practice having conversations with friends and family members to help you adjust to the improved sound quality and clarity provided by your CROS or BiCROS hearing aids.

4. Seek support: Stay in close contact with your audiologist to address any concerns or difficulties you may encounter while adjusting to your hearing aids.

5. Environment Specific: Unlike classic hearing aids, which we would encourage you to wear all day, every day, patients may find that CROS or BiCROS aids are not beneficial in every environment. Pick and choose the environments where they support your hearing needs and eliminate difficulties in comprehension.

6. Be patient: Remember that it takes time to adapt to new hearing aids, so be patient with yourself as you adjust to the changes in your hearing experience.

Conclusion

CROS and BiCROS hearing aids provide a significant improvement in the quality of life for individuals with single-sided hearing loss, particularly those affected by acoustic neuromas. These innovative devices enable users to enjoy a more balanced and natural listening experience, ensuring they remain connected and engaged in their daily lives. If you or a loved one is experiencing SSHL, consult with an audiologist at Pocket Hearing to explore whether CROS or BiCROS hearing aids are the right solution for you.

Frequently Asked Questions about Single-sided Deafness, Acoustic Neuroma, and CROS Hearing Aids

What is Single-sided Deafness (SSD)?

Single-sided Deafness (SSD) refers to a condition where there is significant or total hearing loss in one ear, while the hearing in the other ear remains normal or near-normal. It can result from various causes, including acoustic neuroma, sudden sensorineural hearing loss, or physical trauma.

What is an Acoustic Neuroma?

An Acoustic Neuroma, also known as Vestibular Schwannoma, is a non-cancerous tumour that develops on the vestibulocochlear nerve, which connects the ear to the brain. This tumour can lead to hearing loss, tinnitus, and balance issues, often resulting in Single-sided Deafness (SSD) if it affects the auditory nerve.

How does Single-sided Deafness affect daily life?

Single-sided Deafness can impact a person's ability to localise sound, hear in noisy environments, and maintain balance. It often makes it difficult to determine the direction of sounds, which can be challenging in conversations, group settings, and situations that require spatial awareness.

What are CROS Hearing Aids?

CROS (Contralateral Routing of Signal) hearing aids are designed for people with Single-sided Deafness. They work by capturing sound from the deaf ear and transmitting it to the hearing ear, allowing the user to perceive sounds from both sides. This can improve spatial awareness and the ability to hear in various environments.

Who is a candidate for CROS Hearing Aids?

CROS hearing aids are suitable for individuals with Single-sided Deafness who have little to no hearing ability in one ear but have normal or near-normal hearing in the other ear. A hearing specialist can help determine if CROS hearing aids are the right option based on the individual’s specific condition.

Can CROS Hearing Aids be used after Acoustic Neuroma treatment?

Yes, CROS hearing aids are often recommended for patients who have undergone treatment for Acoustic Neuroma and have resulting Single-sided Deafness. These hearing aids can help improve hearing in situations where traditional hearing aids would not be effective due to the nerve damage caused by the tumour or its treatment.

Understanding CROS and BiCROS Hearing Aids for Single-Sided Hearing Loss