Who Needs a CROS/BiCROS Hearing Aid? A Complete Guide

Introduction

Managing hearing loss presents unique challenges, particularly when it affects one ear more significantly than the other. For individuals with single-sided deafness or asymmetric hearing profiles, standard hearing aids often fall short of addressing their specific needs. This is where specialised solutions like CROS and BiCROS hearing systems become invaluable.

This comprehensive guide explores who can benefit most from these innovative hearing solutions, what conditions they address, and how to determine if they might be right for you or a loved one.

Understanding Asymmetric Hearing Profiles

Before determining who needs a CROS or BiCROS system, it's important to understand the specific hearing profiles these devices are designed to address:

Single-Sided Deafness (SSD)

Single-sided deafness describes a condition where an individual has:

• Normal or near-normal hearing in one ear (thresholds better than 25 dB HL)

• Severe to profound hearing loss in the other ear (thresholds worse than 70 dB HL)

This condition affects approximately 1 in 1,000 adults in the UK, with roughly 9,000 new cases occurring annually. SSD can result from a variety of causes, including sudden sensorineural hearing loss, acoustic neuroma removal, or congenital factors.

Asymmetric Hearing Loss

Asymmetric hearing loss describes a condition where:

• One ear has significantly poorer hearing than the other

• The better ear may also have some degree of hearing impairment

• The difference between ears creates unique listening challenges

This profile is relatively common, with an estimated 15-20% of people with hearing loss experiencing significant asymmetry between their ears.

Candidates for CROS Hearing Systems

CROS hearing systems are specifically designed for individuals who meet particular hearing criteria and experience specific listening challenges.

Audiological Profile for CROS Candidates

You may be a candidate for a CROS hearing system if you have:

• Complete or profound hearing loss in one ear (typically worse than 80-90 dB HL)

• Normal or near-normal hearing in the other ear (typically better than 25 dB HL)

• A non-aidable ear, where traditional amplification provides no meaningful benefit

• Permanent hearing loss that cannot be addressed through medical or surgical intervention

This hearing configuration creates a "dead ear" situation where one side of the head essentially receives no useful auditory information.

Functional Challenges Indicating CROS Need

Beyond the audiometric criteria, functional listening challenges often indicate a need for CROS technology. You might benefit from a CROS system if you regularly experience:

• Difficulty localising sounds in your environment (determining where sounds originate)

• Missing conversations that occur on your impaired side

• Struggling in restaurants, meetings, or social gatherings to follow discussions

• Feeling unsafe due to reduced awareness of environmental sounds from your deaf side

• Constantly repositioning yourself to place your good ear toward the sound source

• Avoiding certain social situations due to communication difficulties

• Experiencing fatigue from the increased concentration required to hear

• Frustration from missed information when someone speaks from your impaired side

Medical Conditions Often Leading to CROS Candidacy

Several medical conditions frequently result in the hearing profile that makes someone a candidate for CROS technology:

• Acoustic neuroma removal (surgical removal of a benign tumour on the hearing nerve)

• Sudden sensorineural hearing loss (SSHL) that did not recover with treatment

• Vestibular schwannoma or other tumours affecting the auditory pathway

• Ménière's disease (in advanced cases where one ear has lost functional hearing)

• Temporal bone fractures or severe head trauma affecting one ear

• Congenital unilateral hearing loss (born with deafness in one ear)

• Viral infections (mumps, measles, or other viral causes of unilateral hearing loss)

• Autoimmune inner ear disease (when affecting one ear significantly more than the other)

Candidates for BiCROS Hearing Systems

BiCROS systems address a more complex hearing profile where both ears have impairment, but to significantly different degrees.

Audiological Profile for BiCROS Candidates

You may be a candidate for a BiCROS hearing system if you have:

• Profound or complete hearing loss in one ear (typically poorer than 80-90 dB HL)

• Mild to moderate hearing loss in the better ear (typically between 25-70 dB HL)

• An unaidable poorer ear that cannot benefit from conventional amplification

• An aidable better ear that can benefit from amplification

• A significant asymmetry between your two ears (typically greater than 40 dB difference)

This profile creates a situation where the better ear needs direct amplification while also needing to receive sound information from the poorer side.

Functional Challenges Indicating BiCROS Need

Individuals who would benefit from BiCROS technology typically experience:

• Difficulty hearing even when sounds are directed toward the better ear

• Problems understanding speech even in relatively quiet environments

• Extreme difficulty in background noise even when positioned strategically

• Increased listening effort leading to fatigue even in one-on-one conversations

• Inability to use a telephone effectively even with the better ear

• Spatial distortion in how sounds are perceived

• Frustration with standard hearing aids that don't address the single-sided component

• Safety concerns due to limited awareness of environmental sounds

Medical Conditions Often Leading to BiCROS Candidacy

BiCROS candidates often develop their hearing profile through:

• Age-related hearing loss (presbycusis) occurring on top of pre-existing single-sided deafness

• Progressive sensorineural hearing loss affecting both ears at different rates

• Bilateral Ménière's disease with asymmetric progression

• Genetic hearing loss with asymmetric expression

• Noise-induced hearing loss affecting one ear more severely than the already-compromised ear

• Ototoxic medication effects causing further decline in a partially-hearing ear

• Auto-immune inner ear disease with bilateral but asymmetric impact

Special Populations Who Benefit from CROS/BiCROS Technology

Certain populations face unique challenges that make CROS or BiCROS technology particularly beneficial:

Children with Unilateral Hearing Loss

Children with single-sided deafness or asymmetric hearing loss face significant educational and developmental challenges:

• Research shows they are 10 times more likely to fail a school year compared to normal-hearing peers

• They experience greater difficulty developing speech and language skills

• They often struggle with attention in classroom environments

• They may develop behavioural issues related to communication frustration

CROS/BiCROS technology can be fitted to children as young as 5-6 years old, providing crucial support during key developmental years.

Working Professionals

Professionals in demanding listening environments often find CROS/BiCROS technology essential for workplace success:

• Teachers who need to hear students from all directions in a classroom

• Business professionals participating in meetings with multiple speakers

• Customer service representatives who interact with the public in noisy environments

• Healthcare workers who must catch critical information in fast-paced settings

• Legal professionals who cannot miss details in courtroom or consultation settings

Active Seniors

Older adults with single-sided or asymmetric hearing loss face particular challenges:

• Increased risk of social isolation and associated cognitive decline

• Safety concerns related to diminished awareness of environmental sounds

• Balance issues that can be exacerbated by asymmetric hearing

• Interaction difficulties in group settings common in retirement communities

CROS/BiCROS technology can help maintain social connections and quality of life for this population.

When CROS/BiCROS May Not Be Appropriate

Despite their benefits, CROS and BiCROS systems are not the right solution for everyone with asymmetric hearing. These systems may not be appropriate for:

• Individuals with significant cognitive impairment who may struggle with the concept of sound redirection

• Those with severe manual dexterity issues who cannot manage two devices

• People with profound tinnitus in their better ear that might be exacerbated by added stimulation

• Individuals whose primary concern is sound localisation, as this remains a limitation even with CROS technology

• Those whose hearing loss in the better ear exceeds the fitting range of available BiCROS receivers

• People who cannot adjust to the sensation of hearing sounds from their deaf side in their better ear

Alternative Solutions to Consider

If CROS/BiCROS technology isn't suitable, several alternatives might be considered:

• Bone conduction devices: Transmit sound through the skull bone to the functioning cochlea

• Cochlear implants: Now increasingly used for single-sided deafness in appropriate candidates

• Contralateral microphone systems: External microphones that transmit to the better ear

• Remote microphone technologies: For specific challenging listening situations

• Communication strategies: Practical approaches to positioning and environment management

The Assessment Process

Determining candidacy for CROS or BiCROS technology involves a comprehensive assessment process:

Audiological Evaluation

A thorough hearing assessment should include:

• Pure-tone audiometry to establish precise hearing thresholds in both ears

• Speech recognition testing in quiet and noise

• Word recognition scores to determine speech understanding

• Functional gain measurements if applicable

• Assessment of dynamic range in the better ear

Lifestyle Assessment

Understanding real-world needs through:

• Detailed case history and lifestyle questionnaire

• Communication demands assessment

• Occupational requirements evaluation

• Social and recreational activity review

Trial Period Importance

Most hearing care professionals recommend a trial period with CROS/BiCROS technology because:

• The experience of hearing from the dead side takes adaptation

• Real-world performance may differ from expectations

• Individual benefit varies significantly between users

• Different models and settings can be evaluated

Typically, a 30-60 day trial provides sufficient experience to determine if the technology meets the individual's needs.

Measuring Success with CROS/BiCROS Systems

How do we know if a CROS or BiCROS system is working effectively? Success can be measured through:

Objective Measures

• Improved speech recognition scores when speech is presented from the impaired side

• Reduced head shadow effect as measured through directional testing

• Lower speech reception thresholds in specific spatial configurations

Subjective Measures

• Self-reported improvement in daily communication situations

• Reduced listening effort and fatigue

• Increased social participation

• Greater confidence in communication

• Improved quality of life scores on validated assessment tools

Conclusion: Is a CROS/BiCROS System Right for You?

CROS and BiCROS hearing systems provide specialised solutions for specific hearing profiles. You might be a candidate for these technologies if you:

• Have profound hearing loss in one ear with better hearing in the other

• Struggle to hear people speaking from your deaf side

• Find yourself constantly repositioning to hear better

• Experience listening fatigue from the effort of compensating for your hearing loss

• Feel excluded in group conversations or noisy environments

• Have safety concerns due to reduced awareness of sounds

The best way to determine if CROS/BiCROS technology is right for you is to consult with an audiologist who specialises in these systems. They can conduct a comprehensive assessment, explain your options, and often arrange a trial period to experience the technology in your daily life.

Remember that adapting to CROS/BiCROS technology takes time as your brain adjusts to the new way of processing sound information. Most users report a period of adjustment followed by significant improvement in their communication ability and quality of life.