Effects of the visual modality on acoustic reflex magnitude.

Acoustic reflex magnitude for nine normal hearing subjects was measured with eyes opened and closed under three visual modality conditions: (1) in darkness; (2) in light without the ability to focus; and (3) in light with the ability to focus. Reflex magnitude decreased with eyes open for all three visual modality conditions; however, greater magnitude reduction occurred when the eyes were able to focus. Magnitude reduction for the three visual conditions was: 7% in darkness; 11% without visual focusing; and 20% with visual focusing. Additional data presented suggests reflex magnitude changes occur when eyes are held open with visual stimulation as a variable.