The impact of noise on auditory processing in children and adults: A time-frequency analysis perspective

The current study investigated the impact of listening conditions on cortical oscillatory activities in adults and children.

Fifteen adults and 15 children participated in this study. Electrophysiological measures were recorded with 64 electrodes. Stimulation was presented binaurally with parameters modulation: stimuli, listening conditions, noise and SNR. Intertrial phase clustering (ITPC) and power values were computed using spatially filtered data and complex Morlet wavelets. Data were statistically analyzed with mixed factorial ANOVAs.

In quiet, children exhibited stronger theta-alpha (ta-) ITPC than adults, especially for verbal stimuli, in bilateral temporal regions, while adults showed no regional differences. Beta-gamma (bg-) ITPC responses revealed that tonal stimuli only elicited stronger right temporal responses in children. Theta-alpha power was greater for tonal stimuli in children, while adults showed stronger right temporal responses. In noise, ta-ITPC reductions were more pronounced in children, especially in babble noise. In white noise, unlike babble noise, there was a systematic reduction of the ta-ITPC values as a function of the SNR level. The bg-ITPC responses were also weaker at lower than higher SNRs. Ta-Power was lower for tonal than verbal stimuli at the right electrode, with greater reductions in babble than in white noise. Bg-Power differences were observed only at the central electrode, where adults showed smaller reductions than children.

Results indicated that phase and power measures are sensitive to parameter modulation and could be used to understand auditory processing in noise, as they revealed increased susceptibility to noise in children compared to adults.