Authors: Paula GarcÃa Zaballos¹, Enrique A. Lopez-Poveda¹, Almudena Eustaquio-MartÃn¹, Milagros J. Fumero¹
¹University of Salamanca
Background: Hearing aid (HA) users frequently struggle in “cocktail-party” environments. While previous research has shown that contralateral sound attenuation (CSA) improves speech recognition in free-field conditions, this study evaluates the benefits of CSA in more realistic, reverberant, and spatially dynamic listening environments.
Method: Eighteen bilateral HA users and ten normal-hearing (NH) listeners performed a keyword recognition task. Stimuli were delivered via a loudspeaker ring (T60 ~ 0.2 s) with a target female voice at 0° and four fluctuating female maskers at ±45° and ±135°. A fifth speech-shaped noise (SSN) masker was placed at random positions (±120°) to prevent spatial predictability. Sounds were captured via an acoustic manikin and presented either unprocessed or processed with the CSA algorithm and individualized nonlinear amplification. Performance was assessed in monaural and bilateral listening conditions.
Results: CSA significantly improved speech recognition for HA users across all conditions: bilateral, left-ear, and right-ear listening (all p ≤ 0.001). NH listeners also demonstrated significant benefits (p < 0.05). Notably, the advantage provided by CSA increased as the unpredictable SSN masker was located further away from the target speech.
Conclusion: Contralateral sound attenuation effectively enhances speech intelligibility for both HA users and NH listeners in complex, multitalker environments. These findings suggest that CSA is a robust strategy for improving communication in realistic, dynamically changing acoustic scenes.
