The Efficacy of Automated Distortion Product Otoacoustic Emission and Automated Auditory Brainstem Response in Universal Hearing Screening

Choi, Byung Yoon; Lee, Myung Chul; Oh, Seung Ha; Kim, Chong Sun; Choi, Jung Hwan; Chang, Sun O

Abstract

BACKGROUND AND OBJECTIVES
Automated auditory brainstem response (AABR) and automated distortion product otoacoustic emission (ADPOAE) are being used in newborn hearing screening in our country nowadays. This study investigates the efficacy of automated tests in newborn hearing screening never disclosed before in our country and establishes the proper newborn screening protocol using two automated hearing screening tools. MATERIALS AND METHOD: 75 normal neonates (150 ears) and 28 high risk neonates (56 ears) have been screened using two automated screening tools from Nov.2002 through Mar.2003. Normal neonates showing "Refer" in any of the two tests and all high risk neonates undertook the conventional ABR (c-ABR), the results of which were considered to be the gold standard reflecting the real hearing threshold, 1 month after the two automated screening tests. The sensitivity and specificity of two automated tests were calculated in neonates who undertook c-ABR and the refer rate of each test was also investigated. Based upon these data, several screening protocols using AABR and ADPOAE were suggested and compared in terms of sensitivity, specificity and refer rate, retrospectively. RESULTS: Sensitivity and specificity of ADPOAE were 100% and 78.5%, with those of AABR being 71.4% and 89.4%, respectively. The refer rates of two tests were 9.7% and 5.33%, respectively. Of 64 ears, which undertook both AABR and c-ABR, 53 ears passed the AABR test. Of those 53 ears that passed AABR, 2 ears showed the hearing threshold of worse than 60dB in c-ABR, with their sweeps being statistically much higher than the means of sweeps of other 51 ears. Of various suggested protocols, the one-step protocol using ABBR alone while taking sweep into consideration, and in which "pass" with high sweep was regarded as "refer, " and the two-step protocol that uses AABR first and ABR next while also taking sweep into consideration, commonly showed the highest efficacy with relatively high sensitivity (100%), and specificity (89.4%), with low refer rate (6.7%). CONCLUSION: The newborn hearing screening protocol using ADPOAE and AABR is less time consuming, efficient, and reliable, especially when we consider the "sweep" in AABR and adopt the two-step screening protocol. This can also serve well to keep pace with the current trend of JCK which recommends neonatal hearing screening in all neonates.