Reliable identification of click-evoked otoacoustic emissions using signal-processing techniques.
As neonatal hearing screening programmes based on click-evolved otoacoustic emissions (CEOAEs) become more common, there is a need for automatic scoring methods to classify responses systematically. Such methods must guard rigorously against errors that would pass a baby who would otherwise fail and be referred for further diagnostic testing. Preliminary analysis of a wide range of CEOAE waveform characteristics from adult and neonatal ears suggested that the most reliable measure on which to base an automatic method was the cross-correlation coefficient between replicate non-linear components. Further analysis of recordings from 2049 ears of 1102 neonates in neonatal intensive care units indicated that a cross-correlation coefficient greater than 0.5 was an appropriate criterion to distinguish a pass from a fail, with the following two provisos. The waveforms should be high-pass filtered to remove random low-frequency components before calculating the cross-correlation coefficient. The cross-correlation coefficient should relate to the time period from 6-16 ms after click onset. Using this method, 90% of recordings were automatically classified in agreement with a proven method of visual scoring. Only one ear without evidence of otoacoustic emission was passed by the automatic scoring method.
Lutman
M E
ME
MRC Institute of Hearing Research, Nottingham, UK.
D000161:Acoustic Stimulation; D000465:Algorithms; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology*; D004432:Ear, Middle / Q000502:physiology; D005260:Female; D006309:Hearing / Q000502:physiology; D006311:Hearing Disorders / Q000175:diagnosis; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening