Hearing LossoCINCT05110183
Opto-electrical Cochlear Implants
A study testing electrical stimulation, optical stimulation and combined optical and electrical stimulation in people with Hearing Loss, run by Northwestern University at 2 sites in United States.
Trial summary
Neural stimulation with photons has been proposed for a next generation of cochlear implants (CIs). The potential benefit of photonic over electrical stimulation is its spatially selective activation of small populations of spiral ganglion neurons (SGNs). Read more about this study
- Who is it for?
- Ages 18 to 89 years
- Conditions the study is for
- Hearing Loss
- What is being tested?
- electrical stimulation, optical stimulation and combined optical and electrical stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 2 sitesUnited States
- Study dates
- 20 Apr 2025to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 89 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Criterion for inclusion of a patient is the requirement of the translabyrinthine approach for tumor removal. The surgical approach is determined by the tumor size, the tumor location and the remaining hearing of the patient. Criteria for a translabyrinthine approach are:
- the tumor grows in the pontine angle and the facial nerve is at risk for damage during the surgery because the tumor is already large and in close proximity of the facial nerve AND
- the tumor is larger than 2.5 cm AND
- Pure tone hearing thresholds are elevated by at least 50 dB AND
- Speech discrimination scores are 50% or less
Who cannot join
- adults unable to consent.
- individuals who are not yet adults (infants, children, teenagers).
- pregnant women.
- prisoners.
- vulnerable populations
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites
University of Missouri
Columbia, Missouri, 65212
University of Miami
Coral Gables, Florida, 33146
About this study
Official title: Opto-Electrical Cochlear Implants
Neural stimulation with photons has been proposed for a next generation of cochlear implants (CIs). The potential benefit of photonic over electrical stimulation is its spatially selective activation of small populations of spiral ganglion neurons (SGNs). Stimulating smaller neuron populations along the cochlea provides a larger number of independent channels to encode acoustic information. Hearing could therefore be restored at a higher fidelity and performance in noisy listening environments as well as music appreciation are likely to improve .
While it has been demonstrated that optical radiation evokes auditory responses in animal models, it is not clear whether the radiant exposures used in the animal experiments are sufficient to stimulate the auditory system of humans. The proposed tests are:
Read more
- to demonstrate that light delivery systems (LDSs) can be inserted and oriented optimally in the human cochlea.
- to show that the LDSs are able to deliver sufficient amount of energy to evoke a compound action potential of the auditory nerve.
- to validate that the fluence rate (energy / target area) required for stimulation is below the maximal fluence rate, which damaged the cochlea in animal experiments.
- to show that combined optical and electrical stimulation is able to significantly lower the threshold required for optical stimulation in humans.
The endpoints for the study are either the completion of the experiments proposed or the demonstration that not sufficient energy can be delivered safely in the human cochlea to develop an action potential.
Read the detailed description
The patient is admitted to one of the participating clinical centers because of a brain tumor, which requires surgery to be removed. As discussed in detail with the treating surgeon, the tumor is large, and an approach will be used that accesses the tumor from the side through the temporal bone. This approach passes by the balance and hearing organ, and the partial or complete removal of the organ responsible for balance and hearing on this side is necessary. Participation in the study will extend the time of surgery by 30 minutes. There is no special preparation and no follow-up required for the study.
In this study, a cochlear implant system that uses light to stimulate the cochlea will be tested. It is a small light delivery system consisting of optical fibers and light sources the size of a human hair. This light delivery system will be inserted into the hearing organ, the cochlea before it is damaged or removed during the tumor surgery. After insertion into the cochlea, pulses of infrared light will be delivered to the cochlea, and auditory responses will be measured with a small electrode placed at the cochlea.
If possible, after completion of the measurements and during the continuation of the tumor surgery, the tissue of the hearing organ, which is typically destroyed through the drilling, will be harvested for histological evaluation.
- Conditions
- Hearing Loss
- Being tested
- electrical stimulation, optical stimulation, combined optical and electrical stimulation
- Keywords
- deaf, neural stimulation with light, cochlear implant
- Medical subject headings
- Hearing Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
electrical stimulationDevice
A cochlear implant electrode will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Custom software on a laptop computer will be used to control the delivery of a sequence of charge balanced current pules.
optical stimulationOther
Optical fibers will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Custom software will be used to control the delivery of a sequence of charge balanced current pules.
combined optical and electrical stimulationOther
A short hybrid array consisting of optical sources and electrical contacts will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Biphasic electrical current pulse and optical pulse delivery will be controlled in amplitude and timing by a computer.
| Study group | Role | What they receive |
|---|---|---|
| electrical and optical hybrid stimulation stimulation | Experimental | Patients with large tumors of the skull base, requiring a translabyrinthine craniotomy with sacrifice of their cochlea and vestibular system during the tumor resection may participate. A recording electrode will be placed on the round window, a cochleostomy will be created, and different Light delivery systems (LDSs) will be inserted into the cochlea. LDSs include angle polished optical fibers to determine the accuracy of the orientation of the radiation beam, and hybrid arrays of small optical sources and electrical contacts to evaluate electric-alone stimulation as a reference, and compare it to optic-alone and combined electrical and optical stimulation. Compound action potentials (CAPs) of the auditory nerve will be recorded. Receives: Device: electrical stimulation; Other: optical stimulation; Other: combined optical and electrical stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Compound Action Potential (CAP)
Compound action potentials (CAPs) of the auditory nerve in response to electrical stimulation, optical stimulation, and combined optical and electrical stimulation will be recorded. Electrical stimulation alone is used to determine baseline cochlear function. Optical stimulation alone will then be used to determine a similar baseline for optical stimulation and test parameters such as optical pulse rate, pulse duration and radiant exposure.
Measured: 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Nov 2021
- Study start20 Apr 2025
- Primary completion1 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hearing LossStudies of the same condition, open and under way.
- More trials run by Northwestern UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Device feasibility
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Northwestern University
- Sponsor type
- University, hospital or other
- Collaborators
- University of Miami, University of Missouri-Columbia, National Institute on Deafness and Other Communication Disorders (NIDCD)
- Responsible party
- Sponsor
- Investigators
- Claus-Peter Richter, MD, PhD, Principal investigator, Northwestern University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05110183
- Sponsor's protocol ID
- STU00209027
- Other IDs
- R01DC018666
- Acronym
- oCI
- Status last verified
- May 2026
- First submitted
- 26 Oct 2021
- Last updated
- 6 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: all IPD that underlie results in a publication
Study at a glance
From the registry record, last updated by the sponsor on 6 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Opto-Electrical Cochlear Implants
- ClinicalTrials.gov ID
- NCT05110183
- Acronym / sponsor ID
- oCI / STU00209027
- Conditions
- Hearing Loss
- Keywords
- deaf, neural stimulation with light, cochlear implant
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Northwestern UniversityUniversity, hospital or other
- Collaborators
- University of Miami, University of Missouri-Columbia, National Institute on Deafness and Other Communication Disorders (NIDCD)
- Study start
- 20 Apr 2025 (actual)
- Primary completion
- 1 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 5 Nov 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Neural stimulation with photons has been proposed for a next generation of cochlear implants (CIs). The potential benefit of photonic over electrical stimulation is its spatially selective activation of small populations of spiral ganglion neurons (SGNs). Stimulating smaller neuron populations along the cochlea provides a larger number of independent channels to encode acoustic information. Hearing could therefore be restored at a higher fidelity and performance in noisy listening environments as well as music appreciation are likely to improve .
While it has been demonstrated that optical radiation evokes auditory responses in animal models, it is not clear whether the radiant exposures used in the animal experiments are sufficient to stimulate the auditory system of humans. The proposed tests are:
- to demonstrate that light delivery systems (LDSs) can be inserted and oriented optimally in the human cochlea.
- to show that the LDSs are able to deliver sufficient amount of energy to evoke a compound action potential of the auditory nerve.
- to validate that the fluence rate (energy / target area) required for stimulation is below the maximal fluence rate, which damaged the cochlea in animal experiments.
- to show that combined optical and electrical stimulation is able to significantly lower the threshold required for optical stimulation in humans.
The endpoints for the study are either the completion of the experiments proposed or the demonstration that not sufficient energy can be delivered safely in the human cochlea to develop an action potential.
Detailed description
The patient is admitted to one of the participating clinical centers because of a brain tumor, which requires surgery to be removed. As discussed in detail with the treating surgeon, the tumor is large, and an approach will be used that accesses the tumor from the side through the temporal bone. This approach passes by the balance and hearing organ, and the partial or complete removal of the organ responsible for balance and hearing on this side is necessary. Participation in the study will extend the time of surgery by 30 minutes. There is no special preparation and no follow-up required for the study.
In this study, a cochlear implant system that uses light to stimulate the cochlea will be tested. It is a small light delivery system consisting of optical fibers and light sources the size of a human hair. This light delivery system will be inserted into the hearing organ, the cochlea before it is damaged or removed during the tumor surgery. After insertion into the cochlea, pulses of infrared light will be delivered to the cochlea, and auditory responses will be measured with a small electrode placed at the cochlea.
If possible, after completion of the measurements and during the continuation of the tumor surgery, the tissue of the hearing organ, which is typically destroyed through the drilling, will be harvested for histological evaluation.
Study design
- Primary purpose
- Device feasibility
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| electrical and optical hybrid stimulation stimulation | Experimental | Device: electrical stimulation, Other: optical stimulation, Other: combined optical and electrical stimulationPatients with large tumors of the skull base, requiring a translabyrinthine craniotomy with sacrifice of their cochlea and vestibular system during the tumor resection may participate. A recording electrode will be placed on the round window, a cochleostomy will be created, and different Light delivery systems (LDSs) will be inserted into the cochlea. LDSs include angle polished optical fibers to determine the accuracy of the orientation of the radiation beam, and hybrid arrays of small optical sources and electrical contacts to evaluate electric-alone stimulation as a reference, and compare it to optic-alone and combined electrical and optical stimulation. Compound action potentials (CAPs) of the auditory nerve will be recorded. |
Who may qualify
- Ages
- 18 to 89 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Criterion for inclusion of a patient is the requirement of the translabyrinthine approach for tumor removal. The surgical approach is determined by the tumor size, the tumor location and the remaining hearing of the patient. Criteria for a translabyrinthine approach are:
- the tumor grows in the pontine angle and the facial nerve is at risk for damage during the surgery because the tumor is already large and in close proximity of the facial nerve AND
- the tumor is larger than 2.5 cm AND
- Pure tone hearing thresholds are elevated by at least 50 dB AND
- Speech discrimination scores are 50% or less
Key exclusion criteria (5 listed)
- adults unable to consent.
- individuals who are not yet adults (infants, children, teenagers).
- pregnant women.
- prisoners.
- vulnerable populations
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| electrical stimulationA cochlear implant electrode will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Custom software on a laptop computer will be used to control the delivery of a sequence of charge balanced current pules. | Device | electrical and optical hybrid stimulation stimulation |
| optical stimulationOptical fibers will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Custom software will be used to control the delivery of a sequence of charge balanced current pules. | Other | electrical and optical hybrid stimulation stimulation |
| combined optical and electrical stimulationA short hybrid array consisting of optical sources and electrical contacts will be inserted through a cochleostomy into scala tympani of the cochlear basal turn. Biphasic electrical current pulse and optical pulse delivery will be controlled in amplitude and timing by a computer. | Other | electrical and optical hybrid stimulation stimulation |
Primary outcome
Compound Action Potential (CAP)
Time frame: 30 minutes
Compound action potentials (CAPs) of the auditory nerve in response to electrical stimulation, optical stimulation, and combined optical and electrical stimulation will be recorded. Electrical stimulation alone is used to determine baseline cochlear function. Optical stimulation alone will then be used to determine a similar baseline for optical stimulation and test parameters such as optical pulse rate, pulse duration and radiant exposure.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 May 2026.
- Individual participant dataSharing planned: Yes. all IPD that underlie results in a publication
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Claus-Peter Richter, MD, PhD principal investigator
Northwestern University
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing electrical stimulation, optical stimulation and combined optical and electrical stimulation in people with Hearing Loss, run by Northwestern University at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Compound Action Potential (CAP) (time frame: 30 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 May 2026; AzTrials last refreshed its copy on 27 Oct 2026.