Intracochlear pressure in cadaver heads under bone conduction and intracranial fluid stimulation

Dobrev, Ivo; Farahmandi, Tahmine S.; Pfiffner, Flurin; Röösli, Christof

doi:10.1016/j.heares.2022.108506

Cited by 9 publications

(14 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During BC stimulation, sounds reach the inner ear by five pathways: inertia of the cochlear fluids, compression of the cochlear walls, middle ear ossicles inertia, sound radiated in the ear canal, and pressure transmission from the cerebrospinal fluid 3 , 4 . Pressure transmission from the cerebrospinal fluid acts only as the stimulus of bone vibrations, so it does not affect the cochlear fluid directly 5 . Theoretical predictions using the lumped element impedance model of the inner ear indicated that in healthy ears, only the first three pathways played a role in the cochlear excitation 6 .…”

Section: Introductionmentioning

confidence: 99%

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Borkowski

2024

Sci Rep

View full text Add to dashboard Cite

Sound transmission to the human inner ear by bone conduction pathway with an implant attached to the otic capsule is a specific case where the cochlear response depends on the direction of the stimulating force. A finite element model of the temporal bone with the inner ear, no middle and outer ear structures, and an immobilized stapes footplate was used to assess the directional sensitivity of the cochlea. A concentrated mass represented the bone conduction implant. The harmonic analysis included seventeen frequencies within the hearing range and a full range of excitation directions. Two assessment criteria included: (1) bone vibrations of the round window edge in the direction perpendicular to its surface and (2) the fluid volume displacement of the round window membrane. The direction of maximum bone vibration at the round window edge was perpendicular to the round window. The maximum fluid volume displacement direction was nearly perpendicular to the modiolus axis, almost tangent to the stapes footplate, and inclined slightly to the round window. The direction perpendicular to the stapes footplate resulted in small cochlear responses for both criteria. A key factor responsible for directional sensitivity was the small distance of the excitation point from the cochlea.

show abstract

Section: Introductionmentioning

confidence: 99%

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Borkowski

2024

Sci Rep

View full text Add to dashboard Cite

show abstract

“… Inertial effects on the middle ear ossicles causing a relative motion between the stapes footplate and the surrounding bone ( Röösli et al, 2012 ; Stenfelt, 2006 ; Stenfelt et al, 2002 ). Sound pressure created in the cranial cavity that is subsequently transmitted to the inner ear via compliant pathways ( Dobrev et al, 2019 , 2022 ; Sohmer et al, 2000 ; Stenfelt & Prodanovic, 2022 ). Inertial effects of the inner ear fluid causing a fluid motion ( Kim et al, 2011 ; Stenfelt, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

“…Four of the five pathways for BC sound transmission described above depend on the skull bone vibration. The inertial effects of the inner ear and the alteration of the inner ear space correlate to the vibration of the cochlear promontory ( Stenfelt, 2015 ), the contribution of middle ear inertia depends on the vibration of the skull bone encapsulating the middle ear ( Stenfelt et al, 2002 ), and the sound pressure in the cerebrospinal fluid is created by the local skull bone vibration ( Dobrev et al, 2022 ; Stenfelt & Prodanovic, 2022 ). The ear canal sound pressure, as discussed in the previous paragraph, can be partly independent of the skull bone vibration.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hearing Through Bone Conduction Headsets

2023

View full text Add to dashboard Cite

Bone conduction (BC) stimulation has mainly been used for clinical hearing assessment and hearing aids where stimulation is applied at the mastoid behind the ear. Recently, BC has become popular for communication headsets where the stimulation position often is close to the anterior part of the ear canal opening. The BC sound transmission for this stimulation position is here investigated in 21 participants by ear canal sound pressure measurements and hearing threshold assessment as well as simulations in the LiUHead. The results indicated that a stimulation position close to the ear canal opening improves the sensitivity for BC sound by around 20 dB but by up to 40 dB at some frequencies. The transcranial transmission ranges typically between −40 and −25 dB. This decreased transcranial transmission facilitates saliency of binaural cues and implies that BC headsets are suitable for virtual and augmented reality applications. The findings suggest that with BC stimulation close to the ear canal opening, the sound pressure in the ear canal dominates the perception of BC sound. With this stimulation, the ear canal pathway was estimated to be around 25 dB greater than other contributors, like skull bone vibrations, for hearing BC sound in a healthy ear. This increased contribution from the ear canal sound pressure to BC hearing means that a position close to the ear canal is not appropriate for clinical use since, in such case, a conductive hearing loss affects BC and air conduction thresholds by a similar amount.

show abstract

“…There are five different pathways that allow a BC sound to stimulate the cochlea in the inner ear. These are (1) the softtissue vibration that produces the ear-canal sound pressure (ECSP) [11]- [13]; (2) the bone vibration that also produces the ECSP [14]; (3) the inertial movement on the middle ear ossicles [15] and the inertia forces of the inner ear fluid [16]; (4) compressions and expansions of the cochlear space [16]; (5) sound pressure transmission from the intracranial content, such as the cerebrospinal fluid (CSF) [17]. Fig.…”

Section: Introductionmentioning

confidence: 99%

Improved Low-Frequency Crosstalk Cancellation in Bone Conduction Using Bone Transducers and Probe Microphone

2022

View full text Add to dashboard Cite

A bone conduction (BC) sound presented on either side of the head will travel to the cochleae in both ears, and this crosstalk phenomenon is considered one factor limiting the benefits of binaural hearing with BC. Previous studies have demonstrated the feasibility of measuring the phase and level required for crosstalk cancellation at the cochlea; however, given a human subject's inability to consistently detect low frequencies, this method is limited to cancellations at frequencies above 1000 Hz. This study describes an alternative approach for implementing a crosstalk cancellation system for low frequencies by measuring ear-canal sound pressure (ECSP). Since the ear canal is close to the cochlea, we hypothesized that altering ECSP in response to a BC stimulation may be used to achieve crosstalk cancellation at the cochlea. Our approach relies on ECSP measurements to estimate impulse responses (IRs) from bone transducers to a probe microphone in the ear canal. The IRs are then used to predict the phase and level required for crosstalk cancellation at the probe microphone's location. To confirm the hypothesis, we measured tone reception threshold (TRT), the lowest tone level participants could detect, under two conditions: with and without crosstalk cancellation. Although crosstalk cancellation was designed to occur at the probe microphone and not at the cochlea, the TRT results showed that participants were still able to perceive cancellations at frequencies below 1000 Hz.

show abstract

Intracochlear pressure in cadaver heads under bone conduction and intracranial fluid stimulation

Cited by 9 publications

References 45 publications

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Hearing Through Bone Conduction Headsets

Improved Low-Frequency Crosstalk Cancellation in Bone Conduction Using Bone Transducers and Probe Microphone

Contact Info

Product

Resources

About