Measurement of acoustic reflexes is an objective (physiological) test as distinct from behavioural tests used for diagnosing APD. Reduced amplitude acoustic reflex functions in children suspected of having APD provide objective evidence of atypical function in the central auditory nervous system in these children.
Saxena, U., Allan, C., & Allen, P. (2015). Crossed and uncrossed acoustic reflex growth functions in normal-hearing adults, typically developing children, and children with suspected auditory processing disorder. International journal of audiology, 54(9), 620-626.