Neural envelope tracking predicts speech intelligibility and hearing aid benefit in children with hearing loss
Early assessment of hearing aid benefit is crucial, as the extent to which hearing aids provide audible speech information predicts speech and language outcomes. A growing body of research has proposed neural envelope tracking as an objective measure of speech, particularly for individuals unable to provide reliable behavioral feedback. However, its potential for evaluating speech intelligibility and hearing aid benefit in hearing-impaired children remains unexplored. This study examined neural envelope tracking in hearing-impaired children through two separate experiments. EEG data was recorded while children listened to age-appropriate stories (experiment 1) or an animated movie (experiment 2) under aided and unaided conditions (using personal hearing aids) at multiple stimulus intensities. Results in the delta band demonstrated that neural tracking increased with increasing stimulus intensity, but only in the unaided condition. In the aided condition, neural tracking remained stable across a wide range of intensities, as long as speech intelligibility was maintained. This suggests that acoustic degradation of the speech signal does not necessarily impact neural tracking. Additionally, the use of personal hearing aids significantly enhanced neural envelope tracking, particularly in challenging speech conditions (which would be inaudible when unaided). Furthermore, neural envelope tracking strongly correlated with behaviorally measured speech intelligibility. Altogether, these findings indicate that neural envelope tracking could be a valuable tool for predicting speech intelligibility benefits derived from personal hearing aids in hearing-impaired children. Incorporating narrated stories or engaging movies expands the accessibility of these methods even in clinical settings, offering new avenues for using objective speech measures to guide pediatric audiology decision-making.