Effects of early childhood otitis media-related conductive hearing loss on speech perception, neural processing, and...

Otitis media with effusion (OME) is a common childhood ear disease that can cause temporary conductive hearing loss during a critical period of auditory development. This condition is hypothesized to be related to deficits in neural, perceptual, and cognitive abilities. This study examined the relation between conductive hearing loss due to OME in early childhood and its effects on neural and perceptual speech processing, as well as working memory (WM) function in early school-aged children. A total of 21 children aged 6-8 years with normal hearing who had a history of OME in early childhood were included in the OME group. In addition, a matched control group of 34 children with no history of ear disease was used for comparison. Perceptual and neural speech-in-noise (SiN) processing were evaluated and compared between the two groups using both electrophysiological and behavioral measures. Specifically, frequency-following responses (FFRs) to the speech syllable /da/ were recorded in quiet and in noise conditions, and latency and amplitude components analyzed. For the perceptual assessment, participants completed a sentence-perception task at three signal-to-noise ratios: +3 dB, 0 dB, and -3 dB. In addition, all participants completed forward and backward digit-span WM tasks. In the quiet condition, the OME group exhibited lower peak amplitudes compared to the control group, whereas in the noise condition, they showed earlier peak latencies, indicating a more resilient neural response to noise. Perceptually, both groups performed similarly on the SiN perception and WM tasks. However, within the OME group, better SiN perception was associated with stronger performance on both forward and backward WM tasks, while in the control group this association was observed only for the forward WM task. School-age children with a history of early OME may exhibit neural and cognitive adaptations that support speech perception in noise. Specifically, enhanced neural encoding and increased reliance on WM may serve as compensatory mechanisms, helping these children maintain performance levels comparable to peers without a history of OME.