Original Article
INTRODUCTIONHearing impairment is a crucial health problem in childhood. Hearing loss is detected in 1-6 of every 1000 live births [1] . In infants, early detection of hearing impairment is essential because of its detrimental effects on speech and language development [2] . Thereby, language, speech, and cognitive functions can be improved using hearing aids or cochlear or brainstem implants [3] .For children with hearing loss, the period around 6 months of age is critical for therapy using hearing aids in order to maximize speech and language development [4] . Today, various audiological test batteries are used for the detection of hearing impairment. Unfortunately, behavioral hearing testing, also called visual reinforcement audiometry, is not reliable before 6 months of age [5] . In infants, auditory brainstem responses (ABRs) and otoacoustic emissions (OAEs) are the main audiological tests for the detection of hearing impairments worldwide [6] . However, both audiological tests have some advantages and disadvantages. As a matter of fact, OAE is a quick test to determine whether hearing is normal or abnormal, whereas ABR provides an assessment of the level of hearing loss [6] . Auditory steady-state response (ASSR) is an alternative objective audiometric test for the detection of hearing loss in neonates, infants, and adults. It has several advantages: (i) the results at each frequency of stimulation can be automatically detected, (ii) there is no need for audiologists to identify the peaks, and (iii) it is easy to apply [7] . Moreover, unlike screening OAE, ASSR can evaluate the frequency-specific responses [8] .Recently, several clinical studies have evaluated the role of ASSR in for the detection of hearing impairment among infants. The aim of this study was to assess the effectiveness of ASSR, determine the cut-off values for each frequency, and detect the best correlated frequencies when compared with the ABR thresholds.
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A Comparison of Thresholds of Auditory Steady-State Response and Auditory Brainstem Response in Healthy Term Babies
OBJECTIVE:The goal of this study was to assess the effectiveness of auditory steady-state response (ASSR), determine the cut-off values for each frequency, and detect the best correlated frequencies when compared with the auditory brainstem response (ABR) thresholds in term babies under the age of 12 months.
MATERIALS and METHODS:In total, 88 term babies with a mean age of 2.98 (1-11) months (174 ears) underwent ASSR and ABR tests. The ASSR thresholds for the frequencies of 500, 1000, 2000, and 4000 Hz were compared with the hearing level of the ABR thresholds. In the ABR test, a cutoff value of 30 dB nHL was selected for normal hearing. In addition, the best correlation between the ABR and ASSR thresholds and the estimated cut-off thresholds of ASSR for each of the abovementioned frequencies were obtained.
RESULTS:In total, 135 ears had values indicating normal hearing ability and 39 ears had hearing loss according to the ABR thresholds. Although stat...