Abstract Background Auditory neuropathy spectrum disorder (ANSD) is characterized by normal OHCs function as shown intact cochlear microphonics (CMs) and/or otoacoustic emissions (OAEs); absent or grossly abnormal auditory brainstem responses (ABRs) and middle ear muscle reflexes. This study designed to address whether the input/output of distortion product OAEs (DPOAEs I/O) in ANSD patients si...