The objective of this study is to develop an optimized hearing testing method using otoacoustic emissions, that can be used to efficiently assess peripheral neural function (including retrocochlear disorders) using the medial olivocochlear reflex (MOCR). Measuring neural function via the MOCR. This reflex has been shown to be abnormal in patients with neural disorders. The focus of this project will be the development of a screening method that incorporates OAE screening and measurement of the MOCR in the same test procedure. The target population in the proposed research is infants, particularly those in environments where auditory brainstem response (ABR) screening is not performed routinely. Addition of the MOCR to screening where ABR is not performed will address the shortcoming of OAE screening which misses neural forms of hearing loss.