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Updated: Jun 6, 2026
06:54
Performing Repeated Intraoperative Impedance Telemetry Measurements during Cochlear Implantation
Published on: August 4, 2023
Implications for contralateral bone-conducted transmission as measured by cochlear vibrations
Måns Eeg-Olofsson1, Stefan Stenfelt, Gösta Granström
1ENT Department, Sahlgrenska University Hospital, Göteborg, Sweden. mans.eeg-olofsson@vgregion.se
Summary
Bone-conducted (BC) stimulation position slightly impacts contralateral cochlear response. Optimal placement near the cochlea may benefit users of bilateral BC hearing aids for improved sound transmission.
Area of Science:
- Auditory neurophysiology
- Biomedical engineering
- Skull mechanics
Background:
- Bone-conducted (BC) sound transmission through the human skull is complex and distinct from air-conducted sound.
- BC sound stimulates both cochleae, influencing hearing perception through amplitude and time delays, which are not fully understood.
- Stimulation position on the skull is a key parameter affecting BC sound transmission.
Purpose of the Study:
- To investigate the velocity response of the contralateral cochlea from BC stimulation at various skull positions.
- To quantify transcranial transmission (TT) and the effects of bilateral stimulation.
- To determine the optimal stimulation position for BC hearing aid applications.
Main Methods:
- BC stimulation was applied at 8 positions on 7 human cadaver skulls.
- Contralateral cochlear promontory velocity response was measured from 0.1 to 10 kHz.
- TT and bilateral stimulation effects were calculated using ipsilateral stimulation data.
Main Results:
- Contralateral transmission showed minor differences across 8 stimulation positions.
- Transcranical transmission (TT) indicated increased cochlear separation when stimulation approached the cochlea.
- Bilateral stimulation effects varied: low-frequency correlated signals had negative effects, uncorrelated signals yielded 3-dB gain; higher frequencies showed less interaction.
Conclusions:
- Stimulation position has a minimal effect on contralateral cochlear velocity response amplitude and phase.
- Ipsilateral transmission significantly influences the response.
- Positioning BC hearing aids close to the cochlea may enhance benefits for patients with bilateral hearing loss.
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