Cognitive load in noise: Neural signatures of speech recognition challenges in children with hearing aids

Despite theoretical models implicating cognitive factors in speech-in-noise (SiN) perception deficits, direct and consistent neurophysiological evidence in children with hearing loss remains scarce. To address this gap, the present study employed a multifaceted electroencephalography approach (ERP, spectral analysis, microstates) to delineate the neurophysiological signatures of Mandarin tone recognition in noise among 20 pediatric hearing aid users. Participants performed a tone identification task under both quiet and noisy (SNR = 10 dB) conditions. Behavioral results revealed a significant decline in accuracy under noise, particularly for perceptually similar tones T2 and T3. Neurophysiological findings demonstrated that noise induced a prolonged P300 latency, which was negatively correlated with behavioral accuracy, constituting a temporal marker of delayed central auditory classification under heightened processing demand. While oscillatory power was predominantly shaped by tone identity, the neural distinction between the challenging T2/T3 pair narrowed to alpha and beta bands under demanding conditions, indicating a constrained spectral mechanism for resolving fine-grained contrasts. Microstate analysis further revealed that noise selectively attenuated the duration and coverage of Microstate 4-a topography spatially consistent with fronto-parietal networks-within the critical 300-600 ms post-stimulus window. These convergent neurophysiological findings indicate that SiN deficits in children with hearing loss may stem not only from peripheral signal degradation but also from a multifaceted bottleneck in central auditory processing efficiency. The study underscores the necessity of ecologically valid assessment paradigms and supports the development of targeted cognitive-auditory training to enhance neural processing efficiency in challenging listening environments.