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Updated: Aug 8, 2026
10:53
Optogenetic Stimulation of the Auditory Nerve
Published on: October 8, 2014
Transcranial conduction of acoustic-reflex-eliciting signals
Summary
Broad-band signals transmitted to the contralateral ear can be detected by acoustic-immittance instruments. These signals mimic acoustic reflexes but can be differentiated and prevented using high-pass filtering.
Area of Science:
- Audiology
- Acoustics
- Bioacoustics
Background:
- Acoustic immittance measures are crucial for assessing middle ear function.
- Understanding signal transmission to the contralateral ear is important for accurate audiological testing.
Purpose of the Study:
- To investigate the conduction of broad-band signals from supra-aural earphones to contralateral acoustic immittance instruments.
- To determine the sound pressure levels (SPL) at which contralateral signal detection occurs.
- To identify potential artifacts in acoustic immittance measurements caused by signal bleed-through.
Main Methods:
- Three commercial acoustic immittance instruments were used.
- Broad-band signals were presented via supra-aural earphones.
- Signal detection and artifact generation in the contralateral ear canal were analyzed.
Main Results:
- Broad-band signals reached the contralateral ear canal at presentation levels of 100-110 dB SPL.
- Signal detection by acoustic immittance instruments occurred as low as 100 dB SPL.
- Transmitted signals created artifacts resembling acoustic reflex responses at higher SPLs.
Conclusions:
- Signal bleed-through to the contralateral ear can occur during supra-aural earphone use.
- Artifacts from signal transmission can be distinguished from true acoustic reflexes.
- High-pass filtering of the test signal effectively prevents these artifacts.
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