Bilateral amplification and sound localization: then and now.

Area of Science:

• Audiology
• Hearing Science
• Speech and Hearing Sciences

Background:

• The debate on bilateral versus monaural hearing aid fitting has historically slowed the adoption of bilateral amplification.
• Despite slow adoption, bilateral amplification is increasingly recognized for its significant advantages over monaural amplification.
• This study investigates the benefits of bilateral hearing aid use, focusing on sound localization capabilities.

Purpose of the Study:

• To compare the sound localization abilities of individuals using bilateral hearing aids versus those using monaural hearing aids.
• To present new data on sound localization symmetry and accuracy in different hearing aid user groups.
• To establish asymmetry in localization judgments as a key indicator of impaired localization ability.

Main Methods:

• Localization tests were conducted on listeners with bilateral hearing aids, monaural hearing aids, and those with asymmetric hearing loss.
• Unaided localization judgments were compared between groups, including normal-hearing listeners.
• Symmetry in perceived angle judgments was analyzed as a primary outcome measure.

Main Results:

• Listeners with bilateral hearing aids and normal-hearing listeners demonstrated high symmetry in sound localization judgments.
• Listeners using monaural amplification and those with asymmetric hearing loss exhibited significant asymmetries in localization.
• Localization judgment asymmetry proved to be a more sensitive measure of abnormal localization than the magnitude of localization errors.

Conclusions:

• Bilateral hearing aid fittings demonstrate superior sound localization symmetry compared to monaural fittings.
• Asymmetry in sound localization judgments is a critical indicator of impaired auditory spatial perception.
• These findings support the widespread adoption of bilateral amplification for enhanced auditory function.