DPOAEs and contralateral acoustic stimulation and their link to sound hypersensitivity in children with autism.

OBJECTIVE

The hypersensitivity of children with autism to sound is a relatively unexplained behavior. The goal of the current study was to investigate the DPOAE characteristics of children with autism compared to a control group.

DESIGN

DPOAEs with and without contralateral stimuli were measured in two groups in three different conditions.

STUDY SAMPLE

The study employed 14 children with autism and a control group with 28 age-matched participants.

RESULTS

In the without-contralateral stimulus condition, the overall S/N of DPOAEs was greater for the control group compared to the autism group (p < 0.0005). For both groups, the DPOAE S/N increased as a function of frequency in both ears. In the with contralateral stimulus condition, group and ear effects were noticed, however, no age, frequency, or contralateral stimulus type (BBN vs. 1000 Hz) effect could be detected.

CONCLUSIONS

Presence of reduced DPOAEs in the autism group does not support the hypothesis that sound hypersensitivity in children with autism may be related to overactive outer hair cells function; rather it may be due to early cochlear dysfunction. Also, sound hypersensitivity in the autism group may be due to abnormality of the efferent auditory pathway as shown by lack of sufficient contralateral suppression.