Biology subjects

Dieudonne, B.

Publications and source records attributed to Dieudonne, B..

5 recordsLinked to original sources

bioRxiv2026

Neural Tracking of Speech Envelope as an Index of Spatial Release from Masking

Understanding speech in noisy environments relies strongly on binaural cues such as interaural time and level differences (ITDs and ILDs), which support spatial hearing and the segregation of competing sound sources. When these cues are degraded, listeners experience substantial difficulty in complex acoustic environments. Behavioural measures of binaural benefit, such as binaural masking level differences, binaural intelligibility level differences, and spatial release from masking (SRM), are well established in normal-hearing (NH) listeners, but they require an active behavioural response. Neural speech tracking using electroencephalography (EEG) has emerged as a promising approach for quantifying neural processing of continuous speech, yet its sensitivity to spatial hearing cues remains insufficiently characterised. We investigated the neural correlates of spatial release from masking in NH listeners using EEG-based neural speech tracking. Nineteen participants listened to continuous Dutch speech stories presented with masking noise under two spatial configurations, collocated (S0N0) and spatially separated (S0N90), across multiple signal-to-noise ratios (SNRs). Neural tracking of the speech envelope was quantified using both envelope reconstruction and temporal response function (TRF) analyses. Spatial separation enhanced neural tracking of the target speech envelope, particularly at challenging SNRs where behavioural SRM was also observed. TRF analysis further revealed increased amplitudes and decreased latencies of late cortical components consistent with spatial unmasking effects. These findings demonstrate that neural speech tracking captures cortical signatures of spatial unmasking and closely reflects behavioural improvements in speech understanding. Establishing these relationships in NH listeners supports the development of objective neural measures for evaluating binaural benefit in difficult-to-test populations.

neuroscience↗

bioRxiv2024

Neural tracking of the speech envelope predicts binaural unmasking

Binaural unmasking is the remarkable phenomenon that it is substantially easier to detect a signal in noise, when the interaural parameters of the signal are different from those of the noise - a mechanism that comes in handy in so-called cocktail party scenarios. In this study, we investigated the effect of binaural unmasking on neural tracking of the speech envelope. We measured EEG in 8 participants who listened to speech in noise at a fixed signal-to-noise ratio (-12 dB or -9 dB, depending on the speech material), in two conditions: one where speech and noise had the same interaural phase difference (both speech and noise having an opposite waveform across ears, S{pi}N{pi}), and one where the interaural phase difference of the speech was different from that of the noise (only the speech having an opposite waveform across ears, S{pi}N0). We measured a clear benefit of binaural unmasking in behavioral speech understanding scores, accompanied with increased neural tracking of the speech envelope. Moreover, analyzing the temporal response functions revealed that binaural unmasking also resulted in decreased peak latencies and increased peak amplitudes. Our results are consistent with previous research using auditory evoked potentials and steady-state responses to quantify binaural unmasking at cortical levels. Moreover, they confirm that neural tracking of speech is modulated by speech understanding, even if the acoustic signal-to-noise ratio is kept constant. Significance StatementBinaural unmasking in an important contributing factor to speech understanding in noisy environments. This is the first time that this benefit in speech understanding is measured objectively with EEG. From a clinical perspective, these results could enable the evalu-ation of binaural speech understanding mechanisms in populations for whom behavioral measures are difficult to obtain, such as young children or people with cognitive impair-ment. Moreover, behavioral research has shown that many pathologies (e.g., asymmetric hearing loss, auditory neuropathy, and age-related deficits) are more sensitive to tests that contain a binaural processing component. Our paradigm could enable the detection of such pathologies with an objective approach using neural tracking of speech.

neuroscience↗

bioRxiv2023

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.

neuroscience↗

bioRxiv2023

Delta-band neural envelope tracking predicts speech intelligibility in noise in preschoolers

Behavioral tests are currently the gold standard in measuring speech intelligibility. However, these tests can be difficult to administer in young children due to factors such as motivation, linguistic knowledge and cognitive skills. It has been shown that measures of neural envelope tracking can be used to predict speech intelligibility and overcome these issues. However, its potential as an objective measure for speech intelligibility in noise remains to be investigated in preschool children. Here, we evaluated neural envelope tracking as a function of signal-to-noise ratio (SNR) in 14 5-year-old children. We examined EEG responses to natural, continuous speech presented at different SNRs ranging from -8 (very difficult) to 8 dB SNR (very easy). As expected delta band (0.5-4 Hz) tracking increased with increasing stimulus SNR. However, this increase was not strictly monotonic as neural tracking reached a plateau between 0 and 4 dB SNR, similarly to the behavioral speech intelligibility outcomes. These findings indicate that neural tracking in the delta band remains stable, as long as the acoustical degradation of the speech signal does not reflect significant changes in speech intelligibility. Theta band tracking (4-8 Hz), on the other hand, was found to be drastically reduced and more easily affected by noise in children, making it less reliable as a measure of speech intelligibility. By contrast, neural envelope tracking in the delta band was directly associated with behavioral measures of speech intelligibility. This suggests that neural envelope tracking in the delta band is a valuable tool for evaluating speech-in-noise intelligibility in preschoolers, highlighting its potential as an objective measure of speech in difficult-to-test populations.

neuroscience↗

bioRxiv2021

Ahead of Maturation: Enhanced Speech Envelope Training Boosts Rise Time Discrimination in Pre-Readers at Cognitive Risk for Dyslexia

Dyslexia has frequently been related to atypical auditory temporal processing and speech perception. Results of studies emphasizing speech onset cues and reinforcing the temporal structure of the speech envelope, i.e. envelope enhancement, demonstrated reduced speech perception deficits in individuals with dyslexia. The use of this strategy as an auditory intervention might thus reduce some of the deficits related to dyslexia. Importantly, interventions are most effective when they are provided during kindergarten and first grade. Hence, we provided a tablet-based 12-week preventive auditory and phonics-based intervention to pre-readers at cognitive risk for dyslexia and investigated the effect on auditory temporal processing with a rise time discrimination task. Ninety-one pre-readers at cognitive risk for dyslexia (aged 5-6) were assigned to two groups receiving a phonics-based intervention and playing a story listening game either with (n = 31) or without (n = 31) envelope enhancement or a third group playing control games and listening to non-enhanced stories (n = 29). Rise time discrimination was measured directly before, directly after and one year after the intervention. While the groups listening to non-enhanced stories mainly improved after the intervention during first grade, the group listening to enhanced stories improved during the intervention in kindergarten and subsequently remained stable during first grade. Hence, an envelope enhancement intervention improves auditory processing skills important for the development of phonological skills. This occurred before the onset of reading instruction, preceding the maturational improvement of these skills, hence giving at risk children a head start when learning to read. Research highlightsO_LIThe first investigation of speech envelope enhancement as a potential preventive intervention strategy in pre-readers at cognitive risk for dyslexia C_LIO_LISpeech envelope enhancement increases the rise time sensitivity of children at cognitive risk for dyslexia C_LIO_LIRise time discrimination can be enhanced before formal reading instruction, a crucial period in development C_LI

neuroscience↗