Reliability and Accuracy of Chirp Based Multiple Auditory Steady State Response (MSSR) and Auditory Brainstem Response (ABR) in Children.

OBJECTIVE: The purpose of this study was to compare the reliability and accuracy of chirp-based Multiple Auditory Steady State Response (MSSR) and Auditory Brainstem Response (ABR) in children. METHODS: The prospective clinical study was conducted at Selayang Hospital (SH) and Hospital Canselor Tuanku Muhriz (HCTM) within one year. A total of 38 children ranging from 3 to 18 years old underwent hearing evaluation using ABR tests and MSSR under sedation. The duration of both tests were then compared. RESULTS: The estimated hearing threshold of frequency specific chirp MSSR showed good correlation with ABR especially in higher frequencies such as 2000 Hz and 4000Hz with the value of cronbach alpha of 0.890, 0.933, 0.970 and 0.969 on 500Hz, 1000Hz, 2000Hz and 4000Hz. The sensitivity of MSSR is 0.786, 0.75, 0.957 and 0.889 and specificity is 0.85, 0.882, 0.979 and 0.966 over 500Hz, 1000Hz, 2000Hz and 4000Hz. The duration of MSSR tests were shorter than ABR tests in normal hearing children with an average of 35.3 minutes for MSSR tests and 46.4 minutes for ABR tests. This can also be seen in children with hearing loss where the average duration for MSSR tests is 40.0 minutes and 52.0 minutes for ABR tests. CONCLUSION: MSSR showed good correlation and reliability in comparison with ABR especially on higher frequencies. Hence, MSSR is a good clinical test to diagnose children with hearing loss.

Age and Gender Effects on Wideband Absorbance in Adults With Normal Outer and Middle Ear Function.

PURPOSE: This study examined the effects of age and gender on wideband energy absorbance in adults with normal middle ear function. METHOD: Forty young adults (14 men, 26 women, aged 20-38 years), 31 middle-aged adults (16 men, 15 women, aged 42-64 years), and 30 older adults (20 men, 10 women, aged 65-82 years) were assessed. Energy absorbance (EA) data were collected at 30 frequencies using a prototype commercial instrument developed by Interacoustics. RESULTS: Results showed that the young adult group had significantly lower EA (between 400 and 560 Hz) than the middle-aged group. However, the middle-aged group showed significantly lower EA (between 2240 and 5040 Hz) than the young adult group. In addition, the older adult group had significantly lower EA than the young adult group (between 2520 and 5040 Hz). No significant difference in EA was found at any frequency between middle-aged and older adults. Across age groups, gender differences were found with men having significantly higher EA values than women at lower frequencies, whereas women had significantly higher EA at higher frequencies. CONCLUSIONS: This study provides evidence of the influence of gender and age on EA in adults with normal outer and middle ear function. These findings support the importance of establishing age- and gender-specific EA norms for the adult population.

High frequency tympanometry findings in neonates: does it depend on head position?

OBJECTIVE: The purpose of this study was to investigate the effect of head positions on high frequency tympanometry (HFT) results obtained from neonates. DESIGN: A cross-sectional study to compare HFT results obtained from neonates in two head positions (face sideways and face up). STUDY SAMPLE: One hundred and fifty-seven neonates (80 female, 77 male; mean age = 48.3 ± 26.7 hours) participated. RESULTS: The mean uncompensated admittance at 200 daPa obtained in the face sideways position was significantly greater than that obtained in the face up position (1.02 versus 0.96 mmho). A significant ear effect for baseline compensated admittance was found (right/left = 0.64/0.53 mmho). However, there were no significant main effects for head positions for the tympanometric peak pressure, baseline compensated static admittance, and component compensated static admittance measures, indicating that these measures are resilient to head positions. CONCLUSION: These findings support the use of HFT normative values regardless of the two head positions investigated in the present study.

Test-retest reliability of the acoustic stapedial reflex test in healthy neonates.

OBJECTIVE: The acoustic stapedial reflex (ASR) test has been shown to provide useful information about the function of the auditory system. However, the reliability of this test when applied to healthy neonates has not been systematically studied. This study aimed to evaluate the test-retest reliability of the ASR test in newborn babies shortly after birth. DESIGN: Using a cross-sectional design, 219 healthy neonates, aged between 24 and 192 hr, who passed an automated auditory brain stem response screening test, were recruited and assessed using transient-evoked otoacoustic emissions (TEOAEs), high-frequency (1000 Hz) tympanometry, and ASR tests. One randomly selected ear from each neonate was tested. ASRs were elicited by presenting a 2 kHz pure tone and broadband noise (BBN) separately to the test ear in an ipsilateral stimulation mode using a Madsen Otoflex diagnostic immittance meter. A total of 194 (86/108 males/females; 115/79 left/right) ears, which met a set of inclusion criteria, were included in the test-retest reliability analysis for the 2-kHz tone stimulus. In addition, 123 (62/61 males/females; 77/46 left/right) ears were included in the test-retest reliability analysis for the BBN stimulus. The ASR threshold (ASRT) for each stimulus was measured. The ASR procedure was then repeated to acquire retest data. RESULTS: Ipsilateral ASRs were elicited in 91.3% (200/219) of neonates, whereas the remaining 8.7% (19/219) exhibited flat tympanograms (no identifiable peak) and absent reflexes with a "refer" outcome in the TEOAE test. The mean ASRT (76.2 dB HL averaged over 194 ears) for the 2 kHz pure tone was higher than that for the BBN (64.9 dB HL averaged over 123 ears). The findings, based on the results of an analysis of variance with repeated measure, showed that the ASRTs for the retest condition did not differ significantly from those of the first test for both stimuli (p > 0.05). The ASR test also showed high test-retest reliability as demonstrated by intracorrelation coefficients across the test-retest conditions of 0.83 for the 2 kHz pure tone and 0.76 for the BBN stimulus. CONCLUSION: This study demonstrated that ASRs could be consistently elicited from healthy neonates who showed a single-peaked configuration in the high-frequency tympanometry test and passed the automated auditory brain stem response and TEOAE tests. The findings showed that the ASRTs did not vary significantly across the test-retest conditions, and the high intracorrelation coefficients illustrate the reliability of the ASR test. Given the high test-retest reliability, the ASR test holds promise as a useful diagnostic/screening instrument in ascertaining the hearing status in neonates.

High frequency immittance findings: newborn versus six-week-old infants.

This study aimed to compare the high frequency (1 kHz) tympanometry (HFT) and acoustic reflex (AR) measures obtained from infants at birth and at 6-7 weeks of age. HFT results and AR thresholds using a 2-kHz tone and broadband noise activators were obtained from 42 healthy full-term neonates (15 boys and 27 girls) at both test sessions, separated by six weeks. The results showed that the mean values of HFT test parameters and AR thresholds obtained at 6-7 weeks were generally greater than those obtained at birth. In particular, the differences in mean values of uncompensated admittance at 200 daPa, uncompensated peak admittance, uncompensated peak susceptance, peak-compensated static admittance, and AR thresholds with a 2 kHz tone and broadband noise were found to be statistically significant. The findings from this study suggest the need to have separate sets of normative HFT and AR data for infants at birth and 6-7 weeks.