Air and Bone Conduction Click and Tone-Burst Auditory Brainstem Thresholds Using Kalman Adaptive Processing in Nonsedated Normal-Hearing Infants

Abstract

Objective To study normative thresholds and latencies for click and tone-burst auditory brainstem response (TB-ABR) for air and bone conduction in normal infants and those discharged from neonatal intensive care units (NICU), who passed newborn hearing screening and follow-up DPOAE. An evoked potential system (Vivosonic Integrity™) that incorporates Bluetooth electrical isolation and Kalman-weighted adaptive processing to improve signal to noise ratios was employed for this study. Results were compared with other published data. Research Design One hundred forty-five infants who passed two-stage hearing screening with transient-evoked otoacoustic emission (OAE) or automated ABR were assessed with clicks at 70 dB nHL and threshold TB-ABR. Tone-bursts at frequencies between 500 to 4000 Hz were employed for air and bone conduction ABR testing using a specified staircase threshold search to establish threshold levels and Wave V peak latencies. Results Median air conduction hearing thresholds using TB-ABR ranged from 0-20 dB nHL, depending on stimulus frequency. Median bone conduction thresholds were 10 dB nHL across all frequencies, and median air-bone gaps were 0 dB across all frequencies. There was no significant threshold difference between left and right ears and no significant relationship between thresholds and hearing loss risk factors, ethnicity or gender. Older age was related to decreased latency for air conduction. Compared to previous studies, mean air conduction thresholds were found at slightly lower (better) levels, while bone conduction levels were better at 2000 Hz and higher at 500 Hz. Latency values were longer at 500 Hz than previous studies using other instrumentation. Sleep state did not affect air or bone conduction thresholds. Conclusions This study demonstrated slightly better Wave V thresholds for air conduction than previous infant studies. The differences found in the current study, while statistically significant, were within the test step size of 10 dB. This suggests that threshold responses obtained using the Kalman weighting software were within the range of other published studies using traditional signal averaging, given step-size limitations. Thresholds were not adversely affected by variable sleep states.

Longitudinal development of wideband reflectance tympanometry in normal and at-risk infants

“…Stimuli for AC were presented via insert earphones (Etymotic Research ER-3A) using pediatric ear foam tips, and stimuli for bone conduction were presented via a B-71 bone oscillator, hand-held at the temporal bone above the pinna. Recording methods and analysis were described by Elsayed, Hunter, Keefe, Feeney, Brown, Meinzen-Derr, Baroch, Sullivan-Mahoney, Francis & Schaid (2015). VRA was completed using the Intelligent Hearing Systems Smart VRA device with insert earphones.…”

Aural Acoustic Stapedius-Muscle Reflex Threshold Procedures to Test Human Infants and Adults

“…All infants were tested at 0.5 and 4 kHz, and data were additionally collected whenever possible at 1 and 2 kHz. Tone-burst ABR procedures are described in Elsayed et al (2015). The inclusion criteria for the normal-hearing infants was also based on a pass on visual reinforcement audiometry (VRA) testing (Widen et al 2000) at a typical age of 9 months.…”

Procedures for ambient-pressure and tympanometric tests of aural acoustic reflectance and admittance in human infants and adults

“…Infants participated in a follow-up diagnostic hearing exam that was performed on average at a corrected age of one month at Cincinnati Children's Hospital Medical Center. The clinical tests included otoscopy, distortion-product otoacoustic emissions (DPOAE, Vivosonic Integrity), and a tone-burst air and bone conduction auditory brainstem response (ABR) test (Vivosonic Integrity) with two to four test frequencies selected at octave frequencies between 0.5 and 4 kHz (Elsayed et al, 2015).…”