Plasticity Changes in Central Auditory Systems of School-Age Children Following a Brief Training With a Remote Microphone System

Abstract

Objectives:The objective of this study was to investigate whether a brief speech-in-noise training with a remote microphone (RM) system (favorable listening condition) would contribute to enhanced post-training plasticity changes in the auditory system of school-age children. Design:Before training, event-related potentials (ERPs) were recorded from 49 typically developing children, who actively identified two syllables in quiet and in noise (+5 dB signal-to-noise ratio [SNR]). During training, children completed the same syllable identification task as in the pre-training noise condition, but received feedback on their performance. Following random assignment, half of the sample used an RM system during training (experimental group), while the other half did not (control group). That is, during training‚ children in the experimental group listened to a more favorable speech signal (+15 dB SNR) than children from the control group (+5 dB SNR). ERPs were collected after training at +5 dB SNR to evaluate the effects of training with and without the RM system. Electrical neuroimaging analyses quantified the effects of training in each group on ERP global field power (GFP) and topography, indexing response strength and network changes, respectively. Behavioral speech-perception-in-noise skills of children were also evaluated and compared before and after training. We hypothesized that training with the RM system (experimental group) would lead to greater enhancement of GFP and greater topographical changes post-training than training without the RM system (control group). We also expected greater behavioral improvement on the speech-perception-in-noise task when training with than without the RM system.Results: GFP was enhanced after training only in the experimental group. These effects were observed on early time-windows corresponding to traditional P1-N1 (100 to 200 msec) and P2-N2 (200 to 400 msec) ERP components. No training effects were observed on response topography. Finally, both groups increased their speech-perception-in-noise skills post-training.Conclusions: Enhanced GFP after training with the RM system indicates plasticity changes in the neural representation of sound resulting from listening to an enriched auditory signal. Further investigation of longer training or auditory experiences with favorable listening conditions is needed to determine if that results in long-term speech-perception-innoise benefits.

Electrophysiological Measures of Listening-in-Noise With and Without Remote Microphone System Use in Autistic and Non-Autistic Youth

“…It is also possible that SNRs greater than +15 dB might be more effective for facilitating the use of higher-order perceptual strategies (i.e., categorical perception) when listening-in-noise. In addition, previous studies in non-autistic participants have suggested that RM system use might elicit neural plasticity changes in a developing auditory system (Hornickel et al 2012; Smart et al 2018; Benítez-Barrera et al 2023). Thus, we might expect RM systems to improve listening-in-noise performance at both the behavioral and neural levels in younger children.…”

“…This finding is consistent with prior reports of better accuracy observed on a variety of behavioral listening-in-noise tasks performed with versus without RM systems (Rance et al 2014; Schafer et al 2016; Feldman et al 2022). Furthermore, a study examining the effects of RM on speech sound processing in noise in non-autistic participants noted that even a brief exposure (10 min) to better SNRs can lead to immediate improvement in behavioral performance on listening-in-noise tasks, including after the RM is removed (Benítez-Barrera et al 2023). Although it is yet to be determined how long such beneficial effects of an RM system last, these findings lend strength to the argument that regular RM use might lead to an improvement in listening-in-noise performance even when not using this technology.…”

“…RA0401; GRAS Sound and Vibration, Holte, Denmark) mounted bilaterally in an acoustic mannequin (Knowles Electronics Manikin for Acoustic Research). The same configuration has been previously used to investigate the effects of RM on CAEPs of non-autistic children (Benítez-Barrera et al 2023).…”

“…1). This configuration resembled realistic listening situations in a classroom environment and reduced the likelihood of the RM microphone picking up the multi-talker babble signal from the two front noise speakers (Benítez-Barrera et al 2023).…”