Preliminary results and considerations in hearing screening of newborns based on otoacoustic emissions.

Many factors may determine the success of a screening programme based on the presence of evoked otoacoustic emissions (EOAEs), including age at test, stimulus used, examiner experience and method of data evaluation. This short report summarizes our experience based on pilot trials of a screen in the whole population of newborns using EOAEs. Optimal test time is when babies are at least 24 h old. Meticulous training of examiners and ultimately automatic evaluation of recordings is essential. Based on visual evaluation of responses to click stimuli at peak-equivalent sound pressure levels of 72.5 and 60.5 dB, 95.5% of babies passed the screen on at least one ear. However, we could only identify an EOAE in 81% of the waveforms for the 60.5 dB stimulus, and only 73% of the non-linear components derived by combining responses to the two stimuli contained an identifiable EOAE. At the present time, examination of both linear and non-linear components is indicated.