Normal development and ear effect for contralateral acoustic reflex in children six to twelve years old

This study investigated the acoustic reflex, which uses the ventro-medial brain-stem system, to determine laterality superiority with respect to age, sex, dominance for handedness, and their various interactions, 54 normal children and 21 normal adults were evaluated. No major effects for age, sex or handedness for the reflex were found, but the right ear appeared slightly more sensitive to broad-band white noise stimuli than the left, regardless of handedness. An age-handedness effect was also present which suggested that left-handed children mature differently from right-handed children in the acoustic reflex. Data on adults were inconclusive as to whether this maturity effect carried over into adulthood. The findings suggest that there was a laterality effect for the acoustic reflex using the ventro-medial brain-stem, which was thus brain-stem related rather than cortex-level related.