The effect of bone vibrator coupling method on the neonate auditory brainstem response

Abstract

Objective: The purpose of this study was to examine the effect of three bone vibrator coupling methods on the neonate auditory brainstem response (ABR).

Design: A repeated measures design was employed. Three coupling techniques were utilised (i.e. hand-held, hand-held applied force gauge and elastic band). ABRs were evoked with a bone-conducted 30 dB nHL 4000 Hz CE-Chirp octave band stimulus. A temporal bone area supero-posterior auricular position for bone vibrator placement was utilised.

Study Sample: Twenty-six healthy full-term neonates participated.

Results: Replicated ABRs were recorded from all neonates for each coupling method. There was a statistically significant effect of coupling on wave V latency (p < 0.001) and amplitude (p < 0.001). There was no statistical difference between the elastic band and the hand-held force gauge coupling for wave V latency and amplitude (p > 0.05). However, the hand-held coupling method produced significantly longer wave V latency and smaller amplitude versus the elastic band and hand-held force gauge (p < 0.001).

Conclusions: Bone vibrator coupling method affects the neonate ABR. Clinicians should be consistent with the choice of coupling while delivering controlled bone-conducted stimuli in ABR assessments in neonates and infants.

Keywords:

• Electrophysiology
• instrumentation
• pediatric
• auditory brainstem response
• bone conduction
• chirp

Declaration of interest

Etymōtic Research, Inc. (Elk Grove Village, IL) provided the force gauge used in this research. No potential conflict of interest was reported by the authors.

Notes

1 The output of the artificial mastoid was routed to a sound level meter (Type 2231, Brüel and Kjær, Duluth, GA) interfaced with a signal acquisition system (Sound Technology Dynamic Signal Acquisition System, Sound Technology inc., Poulsbo, WA) and personnel laptop computer (ThinkPad X1 Carbon, Lenovo, Morrisville, NC). The stimulus was recorded and analyzed using SpectraPlus-SC FFT Spectral Analysis System (Version 5.1.0.33, Pioneer Hill Software LLC, Poulsbo, WA) with a sampling rate of 22,050 Hz with 16-bit sampling. Fast Fourier Transforms (FFTs) were performed with an FFT size of 512 samples, decimation ratio of 1 and a Hanning smoothing window generating an effective resolution of 43.07 Hz.