What is a BiCROS Hearing Aid? A Comprehensive Guide

Introduction

Hearing technology has evolved dramatically to address specific hearing loss configurations. Among these specialised solutions, BiCROS hearing aids represent a significant advancement for individuals with asymmetric hearing loss—those who have profound hearing loss in one ear and some degree of hearing loss in their better ear. Unlike conventional hearing aids designed for symmetrical hearing loss, BiCROS systems offer a unique approach to managing this complex hearing profile.

This comprehensive guide explores what BiCROS hearing aids are, their technological components, how they differ from other hearing solutions, and what makes them uniquely valuable for specific types of hearing loss.

Understanding BiCROS Hearing Aids: The Fundamentals

What BiCROS Stands For

BiCROS is an acronym that stands for "Bilateral Contralateral Routing of Signals." This technical term encapsulates the device's core function:

• Bilateral: Involving both ears

• Contralateral: Crossing from one side to the opposite side

• Routing of Signals: Transmitting sound information from one location to another

This name reflects exactly what the system does—routes sound signals from the poorer-hearing ear to the better-hearing ear while also amplifying sounds at the better-hearing ear.

The BiCROS Configuration

A BiCROS hearing aid system is specifically designed for people with:

1. Profound hearing loss or unaidable hearing in one ear (where traditional amplification provides no benefit)

2. Mild to moderate hearing loss in the other "better" ear (which can still benefit from amplification)

This asymmetric hearing loss pattern creates unique challenges that conventional hearing aids cannot adequately address, making BiCROS technology an important specialised solution.

The Two-Part BiCROS System

A complete BiCROS hearing aid system consists of two essential components that work together:

The Transmitter Unit

The transmitter is worn on the ear with profound or unaidable hearing loss and serves to:

• Capture environmental sounds, speech, and noise from the side with severe hearing loss

• Process these sound signals using digital technology

• Wirelessly transmit the processed signals to the receiver unit on the opposite ear

The transmitter doesn't attempt to make the profoundly deaf ear hear again. Instead, it serves as a sound-gathering device that compensates for that ear's inability to process sound.

The Receiver/Amplifier Unit

The receiver unit, worn on the better-hearing ear (the ear with mild to moderate hearing loss), performs a dual function:

• Receives the wireless signals from the transmitter on the opposite side

• Captures sounds directly from its own side

• Amplifies both sound streams appropriately for the level of hearing loss in that ear

• Delivers the combined, amplified sounds to the better-hearing ear

This integrated approach allows the better ear to receive sound information from both sides of the head, overcoming the "head shadow effect" that would otherwise block sounds from the profoundly deaf side.

The Distinction: BiCROS vs. Other Hearing Solutions

BiCROS vs. Standard Hearing Aids

Standard hearing aids are designed to amplify sounds for ears that have some degree of usable hearing. They assume that:

• The auditory pathway from the ear to the brain is functional

• Amplification can make sounds audible enough to be processed by that pathway

• The ear has enough residual hearing to benefit from amplification

In contrast, BiCROS systems acknowledge that one ear has such profound hearing loss that no amount of conventional amplification will help. Instead of attempting to make that ear hear, BiCROS reroutes sounds to the ear that can still process them.

The "Bi" in BiCROS: What Makes It Different

The "Bi" in BiCROS indicates the bilateral nature of the system's amplification. This is a crucial distinction:

• The system not only routes sounds from the poor ear to the better ear

• It also amplifies sounds at the better ear to compensate for the hearing loss present there

This dual functionality makes BiCROS different from other routing systems that don't provide amplification for the receiving ear. The BiCROS approach recognises that the better ear itself has hearing loss that needs addressing.

Technical Advancements in Modern BiCROS Systems

Wireless Technology Evolution

Modern BiCROS systems have benefited from significant technological advancements:

• From Wired to Wireless: Early BiCROS systems used physical wires to connect the two sides. Contemporary models utilise sophisticated wireless technology for seamless sound transmission.

• Digital Signal Processing: Advanced algorithms process sound before transmission, enhancing speech clarity and reducing unwanted noise.

• Near-Field Magnetic Induction (NFMI): Many systems use this technology for communication between the two devices, providing reliable transmission with low power consumption.

• Bluetooth Connectivity: Latest generation BiCROS systems can connect directly to smartphones and other devices, enabling direct audio streaming to both components of the system.

Form Factor and Design

BiCROS systems are available in various styles to suit different preferences and needs:

• Behind-the-Ear (BTE): The most common configuration, providing powerful processing capabilities

• Receiver-in-Canal (RIC): Offering a smaller behind-the-ear component with a thin wire to a speaker in the ear canal

• In-the-Ear (ITE): More discreet options with components that fit within the ear

Most major hearing aid manufacturers—including Phonak, Signia, Oticon, ReSound, and Widex—offer BiCROS solutions with their own proprietary features and connectivity options.

The Technical Process: How BiCROS Creates a Unified Hearing Experience

The technical functioning of a BiCROS system involves several sophisticated processes:

1. Dual Sound Capture

The system simultaneously:

• Captures sounds from the environment around the profoundly deaf ear via the transmitter unit

• Captures sounds from the environment around the better ear via the receiver unit

2. Sound Processing

Both sound streams undergo digital processing to:

• Enhance speech frequencies

• Reduce background noise

• Balance the sound spectrum for optimal clarity

• Apply user preferences for volume and tone

3. Wireless Transmission

The processed sound from the transmitter is wirelessly sent to the receiver unit using:

• Encrypted digital signals to prevent interference

• Low-latency transmission to ensure sounds stay synchronised

• Energy-efficient protocols to preserve battery life

4. Signal Integration

The receiver unit integrates:

• The wirelessly received sounds from the deaf side

• The directly captured sounds from its own side

• Applying appropriate amplification to both streams based on the hearing loss in the better ear

5. Unified Delivery

The combined, processed, and amplified sound is delivered to the better-hearing ear, creating the perception of hearing from both sides despite using only one functioning auditory pathway.

The BiCROS Fitting and Adjustment Process

Obtaining and optimising a BiCROS system involves a specialised process:

Audiological Assessment

A comprehensive evaluation determines:

• The severity and configuration of hearing loss in both ears

• Whether one ear is truly unaidable

• The degree of amplification needed for the better ear

• Candidacy for BiCROS technology versus other options

Selection and Customisation

The hearing care professional will:

• Select the appropriate BiCROS system based on hearing needs, dexterity, and lifestyle

• Choose the right style and power level for both components

• Programme the system to address the specific hearing loss characteristics

• Customise features like directional microphones and noise reduction

Fitting and Fine-tuning

The initial fitting involves:

• Physical fitting of both components for comfort

• Balancing the sound between the transmitted signals and direct amplification

• Adjusting overall amplification levels

• Setting appropriate compression and output limits

Adaptation Support

Because BiCROS creates a new listening experience, support typically includes:

• Gradual adaptation schedules

• Multiple follow-up appointments for adjustments

• Training in device use, care, and maintenance

• Counselling on realistic expectations and communication strategies

Real-World Applications: When BiCROS Makes a Difference

BiCROS technology proves particularly valuable in specific listening situations:

Group Conversations

Without BiCROS, individuals with profound unilateral hearing loss and some hearing loss in the better ear would miss:

• Speakers positioned on their deaf side

• Comments from across a meeting table

• Participation in dynamic group discussions

BiCROS systems allow awareness of speakers from all directions, integrated into a single hearing experience.

Travelling in Vehicles

In cars and other vehicles:

• Conversation often comes from various positions

• Road noise can make hearing particularly challenging

• People can't easily reposition themselves

BiCROS allows passengers to hear other occupants regardless of seating arrangements, enhancing safety and social connection during travel.

Walking with Companions

When walking side-by-side:

• Without BiCROS, companions would need to stay on the "good" side

• Awareness of environmental sounds from both sides is important for safety

• BiCROS enables flexible positioning and better environmental awareness

In the Workplace

Professional environments often require:

• Awareness of colleagues approaching from any direction

• Participation in meetings without strategic seating

• Overhearing important information from various locations

BiCROS technology helps maintain professional effectiveness by providing comprehensive sound awareness.

Advanced Features in Contemporary BiCROS Systems

Modern BiCROS hearing aids incorporate sophisticated features that enhance their performance:

Directional Microphone Systems

Advanced directional microphones can:

• Focus on speech coming from specific directions

• Adapt automatically to changing sound environments

• Provide better speech understanding in noise

Environmental Classification

AI-powered systems can:

• Identify different listening environments (conversation, music, outdoors)

• Automatically adjust settings for optimal performance in each environment

• Learn user preferences over time

Feedback Cancellation

Sophisticated algorithms eliminate whistling or squealing by:

• Detecting potential feedback paths

• Generating anti-phase signals to cancel feedback

• Maintaining appropriate amplification without compromising sound quality

Connectivity Options

Modern BiCROS systems offer:

• Direct streaming from smartphones and other Bluetooth devices

• Compatibility with remote microphone accessories

• Connectivity to television adapters and other assistive listening devices

• Smartphone apps for discreet control and personalisation

Conclusion: BiCROS as a Specialised Solution

BiCROS hearing aids represent a sophisticated approach to a specific hearing configuration—profound loss in one ear combined with some degree of hearing loss in the other. Rather than attempting the impossible task of restoring hearing to an unaidable ear, BiCROS technology takes a different approach, rerouting sound information while also addressing the hearing needs of the better ear.

For individuals with asymmetric hearing loss configurations, BiCROS technology offers a pathway to improved communication, greater environmental awareness, and enhanced quality of life. As with all hearing technologies, the best outcomes come from professional assessment, appropriate device selection, expert fitting, and ongoing support from qualified hearing healthcare providers.

Understanding what BiCROS technology is—and the specific hearing profile it addresses—is the first step in determining whether this specialised hearing solution might be appropriate for an individual's unique hearing needs.