Early identification of hearing loss in high-risk newborns and young children in Thailand by using transient otoacoustic emissions (TEOAEs)

Abstract

Hearing impairment in prelingual children affects their speech and language development leading to poor educational outcome and results in more effort in habilitation from all levels of related professionals. Many known risk factors have been reported as a possible cause of hearing impairment in newborn and young children. High-risk registration that aimed to search early for newborns at risk of hearing loss was introduced in 1970 in the USA. In the 1980s, ABR became a standard test for hearing screening in young children and TEOAEs screening has - become a standard test since 1990. In Thailand, only ABR was used as a standard test in hearing evaluation in newborn and young children; however, the TEOAEs test has not been tested for its sensitivity and specificity nor for its use in hearing screening in our clinic. This study tried to establish the sensitivity and specificity of TEOAEs for early identification of hearing impairment in newborn and young children compared with conventional ABR. During January 1997 to December 1998, all infants and young children with a high-risk history were included. TEOAEs and conventional ABR were examined in 23 females and 58 males, whose ages ranged from 6 days to 7 years, using the standard protocol for hearing screening. All subjects were tested twice at 3 to 12 months' interval. All medical and family histories were reviewed. Subjects who failed the first screening should be tested by tympanometry to rule out coexisting middle-ear disorders. Of all 81 newborns and young children tested, 28 failed TEOAEs screening (34.5%). Twenty-seven children showed cochlear hearing loss; 20 had bilateral impairment (25%). One had bilateral conductive hearing loss (CHL) due to serous otitis media. Only one who passed the TEOAEs but failed the ABR test was suspected of having retrocochlear hearing impairment in both ears. Twenty of 81 subjects had been diagnosed before the age of 6 months. Five children (25%) had severe SNHL; one (5%) was bilateral. Overall very high sensitivity (>96%) and specificity (>98%) of TEOAEs when compared with ABR were found in this hearing screening. It is recommended that a TEOAEs test should be performed as screening for hearing impairment in newborns and young children at risk of having hearing loss. In complement with a tympanogram and ABR, a diagnosis of CHL and retrocochlear hearing impairment could be disclosed.