Introduction: Age-related hearing loss significantly impacts the ability to understand speech, especially in noisy environments. While changes in the peripheral auditory system contribute to this difficulty, increasing evidence indicates that central auditory processing and cognitive functions also play critical roles in speech perception. This study investigates the complex relationship between age-related hearing loss, cognitive function changes, and difficulties in speech perception amidst noise in elderly individuals.

Method: The study used a prospective cross-sectional design with two groups of participants: 20 individuals aged 60 to 80 years with mild to moderately severe sensorineural hearing loss (Group 1) and 20 age- and education-matched controls with normal or near-normal hearing sensitivity (Group 2). Speech-in-noise perception was assessed using the Quick Speech-in-Noise (Quick SIN) test, which evaluated participants' performance across varying signal-to-noise ratios (SNRs) ranging from +20 to -10 dB. Cognitive functions were evaluated through computerized assessments, including attention network tests and N-Back tests, alongside simultaneous 32-channel EEG recordings.

Results and Discussion: The findings revealed significant correlations between central hearing abilities (measured as SNR Loss) and cognitive performance. A moderate to strong correlation was found between SNR Loss and cognitive scores, particularly in executive attention and working memory. A negative correlation was identified between EEG amplitude and hearing abilities, indicating that decreased neural responses were associated with increased central auditory loss. Furthermore, a positive correlation between central hearing abilities and reaction time suggested that individuals with more significant SNR loss needed more time to process information. The significant correlations between executive attention, working memory, and speech-in-noise perception indicate that cognitive processes related to task management (suppressing noise and focusing on speech) and information retention (retaining and recalling spoken information) are crucial for understanding speech in challenging auditory environments. In contrast, the lack of impact from alerting and orienting networks suggests that simply being aware or directing focus does not significantly improve one's ability to perceive speech in noisy conditions.

Conclusion: The results indicate that difficulties in speech perception in noisy environments arise from peripheral hearing loss, changes in central auditory processing, and cognitive decline, particularly in executive functions and working memory. This study provides valuable insights into the intricate relationships between auditory processing and cognitive functions in elderly individuals with hearing loss, emphasizing the need for comprehensive assessment and rehabilitation approaches that address both auditory and cognitive aspects of speech perception in noise.