DESIGN: Quasi-experimental and repeated measure study designs were applied in this study. Two different stopping criteria were used, (1) a fixed-signal averaging 4000 sweeps and, (2) a minimum quality indicator of Fmp = 3.1 with a minimum of 800 sweeps.
STUDY SAMPLE: Twenty-nine normally hearing adults (18 females, 11 male) participated.
RESULTS: Wave V amplitudes were significantly larger in the LS CE-Chirp® recorded from the vertical montage than the ipsilateral montage. Waves I and III amplitudes were significantly larger from the ipsilateral LS CE-Chirp® than from the other montages and stimulus combinations. The differences in the quality of the ABR recording between the vertical and ipsilateral montages were marginal.
CONCLUSIONS: Overall, the result suggested that the vertical LS CE-Chirp® ABR had a high potential for a threshold-seeking application, because it produced a higher wave V amplitude. The Ipsilateral LS CE-Chirp® ABR, on the other hand, might also have a high potential for the site of lesion application, because it produced larger waves I and III amplitudes.
Method: Quasi-experimental and repeated-measures study designs were used in this study. Twenty-six adults with normal hearing (17 females, 9 males) participated. ABRs were acquired from the study participants at 3 intensity levels (80, 60, and 40 dB nHL), 3 frequencies (500, 1000, and 2000 Hz), 2 electrode montages (ipsilateral and vertical), and 2 stimuli (NB LS CE-Chirp and tone-burst) using 2 stopping criteria (fixed averages at 4,000 sweeps and F test at multiple points = 3.1).
Results: Wave V amplitudes were only 19%-26% larger for the vertical recordings than the ipsilateral recordings in both the ABRs obtained from the NB LS CE-Chirp and tone-burst stimuli. The mean differences in the F test at multiple points values and the residual noise levels between the ABRs obtained from the vertical and ipsilateral montages were statistically not significant. In addition, the ABR elicited from the NB LS CE-Chirp was significantly larger (up to 69%) than those from the tone-burst, except at the lower intensity level.
Conclusion: Both the ipsilateral and vertical montages can be used to record ABR to the NB LS CE-Chirp because of the small enhancement in the wave V amplitude provided by the vertical montage.
OBJECTIVE: To study the effectiveness of distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (AABR) as first screening tool among non-risk newborns in a hospital with high delivery rate.
METHOD: A total of 722 non-risk newborns (1444 ears) were screened with both DPOAE and AABR prior to discharge within one month. Babies who failed AABR were rescreened with AABR ± diagnostic auditory brainstem response tests within one month of age.
RESULTS: The pass rate for AABR (67.9%) was higher than DPOAE (50.1%). Both DPOAE and AABR pass rates improved significantly with increasing age (p-value<0.001). The highest pass rate for both DPOAE and AABR were between the age of 36-48 h, 73.1% and 84.2% respectively. The mean testing time for AABR (13.54 min ± 7.47) was significantly longer than DPOAE (3.52 min ± 1.87), with a p-value of <0.001.
CONCLUSIONS: OAE test is faster and easier than AABR, but with higher false positive rate. The most ideal hearing screening protocol should be tailored according to different centre.
Methods: This cohort study was designed to screen the hearing of newborns using transiently evoked otoacoustic emission and auditory brain stem response, and to determine the risk factors associated with hearing loss of newborns in 3 tertiary hospitals in Northern Thailand. Data were prospectively collected from November 1, 2010 to May 31, 2012. To develop the risk score, clinical-risk indicators were measured by Poisson risk regression. The regression coefficients were transformed into item scores dividing each regression-coefficient with the smallest coefficient in the model, rounding the number to its nearest integer, and adding up to a total score.
Results: Five clinical risk factors (Craniofacial anomaly, Ototoxicity, Birth weight, family history [Relative] of congenital sensorineural hearing loss, and Apgar score) were included in our COBRA score. The screening tool detected, by area under the receiver operating characteristic curve, more than 80% of existing hearing loss. The positive-likelihood ratio of hearing loss in patients with scores of 4, 6, and 8 were 25.21 (95% confidence interval [CI], 14.69-43.26), 58.52 (95% CI, 36.26-94.44), and 51.56 (95% CI, 33.74-78.82), respectively. This result was similar to the standard tool (The Joint Committee on Infant Hearing) of 26.72 (95% CI, 20.59-34.66).
Conclusion: A simple screening tool of five predictors provides good prediction indices for newborn hearing loss, which may motivate parents to bring children for further appropriate testing and investigations.
METHODS: A retrospective descriptive cohort study on the audiological findings detected during the first hearing assessment done on a child with craniosynostosis using otoacoustic emissions, pure tone audiometry or auditory brainstem response examination. The main aim of this study was to evaluate the type and severity of hearing loss when compared between syndromic and non-sydromic craniosynostosis, and other associated contributory factors.
RESULTS: A total of 31 patients with 62 ears consisting of 14 male patients and 17 female patients were evaluated. Twenty two patients (71%) were syndromic and 9 (29%) were non-syndromic craniosynostosis. Amongst the syndromic craniosynostosis, 9 (41%) had Apert syndrome, 7 (32%) had Crouzon syndrome, 5 (23%) had Pfieffer syndrome and 1 (4%) had Shaethre Chotzen syndrome. Patients with syndromic craniosynostosis were more likely to present with all types and severity of hearing loss, including severe to profound sensorineural hearing loss while children with non-syndromic craniosynostosis were likely to present with normal hearing (p
METHOD: A prospective analysis was conducted on 173 patients (346 ears) with cleft lip and palate (CL/P) who presented to the combined cleft clinic at University Malaya Medical Centre (UMMC) over 12 months. The patients' hearing status was determined using otoacoustic emission (OAE), pure tone audiometry (PTA) and auditory brainstem response (ABR). These results were analysed against several parameters, which included age, gender, race, types of cleft pathology, impact and timing of repair surgery.
RESULTS: The patients' age ranged from 1-26 years old. They comprised 30% with unilateral cleft lip and palate (UCLP), 28% with bilateral cleft lip and palate (BCLP), 28% with isolated cleft palate (ICP) and 14% with isolated cleft lip (ICL). Majority of the patients (68.2%) had normal otoscopic findings. Out of the 346 ears, 241 ears (70%) ears had passed the hearing tests. There was no significant relationship between patients' gender and ethnicity with their hearing status. The types of cleft pathology significantly influenced the outcome of PTA and ABR screening results (p