[P1-17] Developmental trajectories of auditory sensitivity to human voice in children with and without autism spectrum disorder
Children with autism spectrum disorder (ASD) often exhibit weaker orientation toward social signals, such as human faces. However, it is unclear whether children with ASD are less sensitive to human voices, as well as the developmental trajectory of the social orientation towards them. Therefore, we developed a new audiometric test to evaluate the sensitivity to human voices and aimed to reveal its typical and atypical developmental trajectories. 1835 normal children (3 - 13 years old) were examined individually for their auditory threshold of detecting human voices and environmental sounds (i.e., non-voice) in noise. As a result, the detection threshold for human voices was lower than that of non-voices in all age groups (p < .000). The sensitivity to human voices improved gradually over age (p < .000). Moreover, it was correlated with the social awareness score (p < .01), which indicated that children with lower social awareness tended to have reduced sensitivity to human voices. Subsequently, we compared 21 children with ASD (9 - 15 years old) with 448 age-matched normal children. As a result, children with ASD were overall better at detecting non-voices than human voices and were less sensitive to human voices than normal children (p < .000). These results indicate that children with ASD have deficits in orientation toward human voices and were suggested to follow atypical developmental trajectory of the social orientation. In addition, the present result showed the availability of this newly-invented audiometric test as a screening tool to identify children with ASD.