Quantification of the relationship between crossed and uncrossed acoustic reflex amplitudes.

Acoustic reflex amplitude data were obtained for 92 subjects. Uncrossed (ipsilateral) and crossed (contralateral) acoustic reflex activity was measured simultaneously and computer averaged with specially constructed apparatus. For all subjects, amplitude was greater for uncrossed than crossed acoustic reflexes. The ratio of maximum uncrossed versus crossed reflex amplitude for young normal-hearing subjects ranged from 1.06 to 2.38, with an average of 1.50. This relationship was not significantly influenced by subject age, sensorineural hearing impairment, or mild abnormalities in acoustic immittance. Clinical investigation of the diagnostic application of the uncrossed versus crossed reflex amplitude ratio in central auditory nervous system pathology is suggested.