A prospective study of the application of click evoked oto-acoustic emissions and brainstem electric response audiometry to detect hearing impairment at birth : J.C. Stevens, H. Webb, J. Hutchinsona, J. Connella, M.F. Smithb and J.T. Buffina Department of Medical Physics and Clinical Engineering Royal Hallamshire Hospital, Sheffield, S10 2JF, aDeparment of Audiology, Sheffield Childrens Hospital and bNeonatal Unit, Jessop Hospital for Women, Sheffield, U.K.