Auditory event-related potentials index faster processing of natural speech but not synthetic speech over nonspeech analogs in children

• Published in: Brain and language Vol. 207; p. 104825
• Main Authors: Whitten, Allison, Key, Alexandra P., Mefferd, Antje S., Bodfish, James W.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01-08-2020
• Subjects: Attention - physiology; Auditory processing; Child; Child Language; Children; Event-related potential (ERP); Evoked Potentials, Auditory - physiology; Female; Humans; Male; Natural stimuli; Nonspeech; Phonetics; Speech; Speech Perception - physiology; Speech; Natural stimuli; Children; Auditory processing; Event-related potential (ERP); Nonspeech
• ISSN: 0093-934X; 1090-2155
• DOI: 10.1016/j.bandl.2020.104825

•Auditory ERP latencies to natural speech were significantly faster than a natural nonspeech analog in children.•Auditory ERP latencies to synthetic speech were not significantly faster than a synthetic nonspeech analog.•The maturity of auditory ERPs in 8–11-year-old children differed between simple synthetic and complex natural sounds.•Natural speech may be processed more efficiently due to the significance of and greater experience with the human voice.•These results highlight the importance of using ecologically valid speech stimuli in neuroimaging research.
Given the crucial role of speech sounds in human language, it may be beneficial for speech to be supported by more efficient auditory and attentional neural processing mechanisms compared to nonspeech sounds. However, previous event-related potential (ERP) studies have found either no differences or slower auditory processing of speech than nonspeech, as well as inconsistent attentional processing. We hypothesized that this may be due to the use of synthetic stimuli in past experiments. The present study measured ERP responses during passive listening to both synthetic and natural speech and complexity-matched nonspeech analog sounds in 22 8–11-year-old children. We found that although children were more likely to show immature auditory ERP responses to the more complex natural stimuli, ERP latencies were significantly faster to natural speech compared to cow vocalizations, but were significantly slower to synthetic speech compared to tones. The attentional results indicated a P3a orienting response only to the cow sound, and we discuss potential methodological reasons for this. We conclude that our results support more efficient auditory processing of natural speech sounds in children, though more research with a wider array of stimuli will be necessary to confirm these results. Our results also highlight the importance of using natural stimuli in research investigating the neurobiology of language.