Audiometric Estimation Error with the ABR in High Risk Infants

Abstract

Click ABR wave V thresholds in the first year were compared with follow-up behavioural puretone audiometry under earphones at age 3 to 6 years in 713 infants (yielding 1367 ears) at risk for hearing loss. The observed accuracy of the ABR depends strongly on the precise definitions of the target disorder and the test abnormality criteria. For sensorineural hearing loss of more than 20 dB averaged at 2 kHz and 4 kHz, the click ABR provides an accurate test, with both false positive and false negative rates of less than 10%, using an ABR threshold criterion of 30 dB nHL. The false positive error rate can be at least halved by using a simple rule for wave V latency that discriminates conductive and sensorineural ABR threshold abnormalities. False negative errors may be explicable in terms of the lack of frequency specificity of the click stimulus.

Key Words:

• auditory brainstem response (ABR)
• wave V latency
• infant hearing screening