What does a recommendation for binaural amplification entail in a patient with bilateral or asymmetrical sensorineural hearing loss?

Binaural Amplification: Definition and Clinical Application

Binaural amplification means fitting hearing aids to both ears simultaneously in patients with bilateral sensorineural hearing loss, which provides superior speech recognition in noise, sound localization, and quality of life compared to amplifying only one ear. 1

What Binaural Amplification Entails

Core Concept

• Binaural amplification involves placing hearing aids on both ears to restore bilateral auditory input and take advantage of the brain's ability to process sound from both sides simultaneously 2
• This approach is distinct from monaural (one ear) amplification and should be the default recommendation for patients with symmetric bilateral hearing loss 3, 4

Clinical Benefits Documented

Speech Understanding:

• Bilateral amplification provides improved speech recognition in background noise through binaural summation and the ability to separate competing sound sources 2, 5
• The binaural advantage for speech-in-noise performance is comparable to the benefit seen in normal-hearing individuals when listening with two ears versus one 5
• Speech reception thresholds improve by approximately 4.4 dB in quiet conditions with binaural versus monaural listening 5

Sound Localization:

• Binaural fitting enables sound localization abilities, which are essentially impossible with monaural amplification 2, 5
• Studies show 53% improvement in correct sound source identification (within 45 degrees) with bilateral versus unilateral bone-anchored hearing aids 5

Quality of Life Impact:

• Amplification reduces psychosocial and emotional manifestations of hearing loss and improves health-related quality of life 1
• Bilateral amplification is preferred by 90% of first-time hearing aid users for consistent reasons related to improved hearing function 4

When to Recommend Binaural Amplification

Primary Indication:

• All patients with bilateral symmetric sensorineural hearing loss should be offered binaural amplification as the initial approach 3, 4
• This applies to both traditional hearing aid candidates and those with asymmetric hearing who may benefit from bimodal stimulation (cochlear implant in one ear, hearing aid in the other) 2

Special Populations:

• Elderly patients with symmetric hearing loss should attempt bilateral amplification unless specific contraindications exist 3
• Children with bilateral hearing loss require binaural fitting to support speech and language development 1

Important Caveats and Contraindications

Binaural Interference:

• A minority of patients may experience binaural interference, where two hearing aids perform worse than one, particularly in background noise 6
• Older patients show greater tendency for bilateral amplification to have deleterious effects in certain noisy environments 6
• When patients report difficulty understanding speech in noise with bilateral aids, removing one hearing aid may paradoxically improve performance 6

Practical Limitations:

• Bilateral fitting involves increased costs, cosmetic concerns, and additional management complexity for patients with limited dexterity 3
• Some patients may prefer unilateral amplification despite objective binaural advantages 3

When NOT to Use Binaural Amplification:

• Unilateral hearing loss (single-sided deafness) requires different solutions such as CROS (Contralateral Routing of Signal) or BiCROS systems, not traditional binaural amplification 1
• Severe asymmetric hearing loss where one ear has profound loss may benefit from CROS/BiCROS rather than conventional bilateral aids 1
• Documented binaural interference after appropriate trial period warrants monaural fitting 3, 6

Clinical Implementation Algorithm

Initial Assessment:

• Verify bilateral symmetric hearing loss through comprehensive audiometry 1
• Use self-assessment tools (Hearing Handicap Inventory) to quantify functional impact 1

Fitting Protocol:

• Fit both ears simultaneously with appropriately programmed digital hearing aids 1
• Provide controlled trial periods (minimum 1 hour, then 2 days, then extended home trial) to assess subjective preference 4
• Monitor for consistency of preference throughout trial period, which predicts successful long-term use 4

Follow-Up Evaluation:

• Test speech-in-noise performance (QuickSIN or similar) with bilateral versus unilateral amplification 6
• If bilateral performance is worse, consider ear-specific testing to identify the better-performing ear 6
• Counsel patients that removing one aid in specific noisy situations may be appropriate even with successful bilateral fitting 6

Long-Term Management:

• Document changes in hearing, quality of life, and device effectiveness at follow-up visits 1
• Adjust amplification as hearing fluctuates or progresses 1
• Consider alternative technologies (CROS, bone-anchored devices, cochlear implants) if conventional binaural amplification provides limited benefit 1