Cochlear Promontory Stimulation for Treatment of Tinnitus

August 20, 2025 updated by: Matthew L. Carlson, M.D., Mayo Clinic

Cochlear Promontory Stimulation for Treatment of Tinnitus: Towards Developing an Implantable Device

Tinnitus is the perception of sound when no external noise is present. The Center for Disease Control (CDC) estimates over 50 million - nearly 15% of the general public -experience some form of tinnitus. Roughly 20 million people struggle with burdensome chronic tinnitus, with 2 million experiencing extreme and debilitating symptoms.

The 2014 Clinical Practice Guideline on tinnitus from the American Academy of Otolaryngology - Head and Neck Surgery summarized the existing state of tinnitus management by stating "A cure for primary tinnitus does not yet exist, and despite claims to the contrary, no method has been proven to provide long-term suppression of tinnitus."

The purpose of this study is to look at the safety and efficacy of cochlear promontory stimulation in the short term relief of tinnitus. The secondary goal of the study is to determine the optimum region(s) of the cochlear promontory in planning for an implantable electrical device for long term tinnitus suppression.

Study Overview

Status

Completed

Conditions

Detailed Description

Candidate subjects will undergo a temporal bone Computed Tomography (CT) scan, contrast enhanced head Magnetic Resonance Imaging (MRI), audiogram with immittance testing, pitch and level matching of tinnitus, Distortion Product Otoacoustic Emissions (DPOAE) and Auditory Brainstem Response (ABR) testing prior to promontory stimulation. Head MRI, DPOAE, audiogram and immittance testing are considered clinically routine for assessment of asymmetric tinnitus. Temporal bone CT, ABR, tinnitus pitch, level matching, masking levels and residual inhibition testing are not standard clinical assessments for asymmetric tinnitus. In addition, subjects will complete the Tinnitus Handicap Inventory (THI), Tinnitus Functional Index (TFI) and Visual Analog Scale (VAS) questionnaires three separate times within the week prior to promontory stimulation testing. Additional testing for comorbid anxiety and depressive conditions will be a screening Generalized Anxiety Disorder (GAD7), Patient Health Questionnaire (PHQ8), and short Health Anxiety Inventory (HAI-S). The NEO Personality Inventory (NEO PI) will be administered to provide baseline information. The initial session of promontory stimulation will define optimal stimulation parameters (i.e., location, current level, pulse-width, phase polarity), where maximal tinnitus suppression occurs with minimal or no auditory percept. After these parameters are established, the patient will complete the THI, TFI, and VAS immediately prior to stimulation, during stimulation, and following completion of stimulation at 10-minutes, 1-hour, 24-hours, 48-hours, and 1-week following completion of stimulation. In addition, pitch and level matching of tinnitus will be completed immediately upon completion of each promontory stimulation session. Each patient will undergo three successive treatments separated by 1-week. Prior to each treatment, the patient will receive an audiogram and DPOAE testing to document interval safety. At the conclusion of the study, subjects will be asked about their willingness to undergo surgical implantation of a device capable of long-term scheduled or on-demand electrical stimulation for tinnitus suppression

Study Type

Interventional

Enrollment (Actual)

25

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic in Rochester

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Normal to moderate sensorineural hearing loss (based on pure tone audiometry (PTA) of 500, 1000 and 2000 Hz) and a word recognition score equal to or greater than 60%
  2. Asymmetric or unilateral subjective tonal tinnitus
  3. Tinnitus that is disruptive

    1. Determined by THI score (in the severe range i.e. ≥56/100)
    2. TFI (in the severe range i.e. ≥52/100)
    3. Tinnitus VAS (≥ 5/10 )
  4. Tinnitus that is intractable, and has not been ameliorated by conventional measures such as a hearing aid or masking
  5. Normal contrast-enhanced MRI of the head

Exclusion Criteria:

  1. Tinnitus present less than 6 months or longer than 12 years; it is permissible to include people who have had intermittent or constant tinnitus longer than 12 years as long as it was not perceived as severe longer than 12 years
  2. History of brain or major ear surgery
  3. Prior major head trauma
  4. Ongoing clinical diagnosis of depression or anxiety; for the purposes of this study, it is permissible to include people who: 1. have a past history of clinically diagnosed depression or anxiety that is no longer currently active; or 2. people who have depressive or anxious symptoms that are thought to primarily result from severe tinnitus

    a. Determined by screening using the GAD 7, PHQ8, and HAI-S

    • GAD7 > 9 (indicates clinically significant anxiety)
    • PHQ > 9 (indicates clinically significant depression)
    • HAI-S > 25 (hypochondriacal level illness anxiety)
  5. Inability to assess, continue or complete trial
  6. Currently on regularly scheduled antidepressants, anxiolytics or antipsychotics; for this study, it is permissible to include people who use such medications at lower doses as a sleep aid or for people who intermittently use such medications for situational anxiety (e.g., Ativan before airplane travel)
  7. Active use of other tinnitus treatments; for the purposes of this study it is permissible to include people who prefer to use a hearing aid to amplify ipsilateral hearing loss
  8. Known pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Testing Arm
There will only be one arm. The patient and investigator will initially be blinded to the "on-off" status of the electrode. The patient will thus serve as an internal control for testing. Once device integrity and possible benefit is confirmed, the patients will undergo non-tactile electrical stimulation to the bone of the inner ear (cochlear promontory) for short term relief of tinnitus via Cochlear promontory stimulation.
Promontory stimulation is an established otologic procedure that was initially developed as a diagnostic tool to assess patient candidacy for cochlear implantation. Promontory stimulation is most commonly performed in the outpatient setting on an awake patient by placing a single insulated probe through a topically anesthetized tympanic membrane and applying monopolar current for several seconds to minutes. The initial session of promontory stimulation will define optimal stimulation parameters (i.e., location, current level, pulse-width, phase polarity), where maximal tinnitus suppression occurs with minimal or no auditory percept. Additional stimulation testing visits will confirm these findings.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Short Term Relief of Tinnitus as Measured by the Tinnitus Handicap Inventory
Time Frame: Baseline to 4 months
The Tinnitus Handicap Inventory (THI) has 25 questions with possible answers of Yes (4 points), Sometimes (2 points), and No (0 points). Scores categories are (1-16: Slight or no handicap - Grade 1), (18-36: Mild handicap - Grade 2), (38-56: Moderate handicap - Grade 3), (58-76: Severe handicap - Grade 4), (78-100: Catastrophic handicap - Grade 5). Total score ranges from 0 to 100 with higher scores indicating a worse outcome.
Baseline to 4 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Optimal Location of Tinnitus Relief
Time Frame: Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
Location on the cochlear promontory where highest perceived benefit from electrical stimulation
Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
Auditory Feedback
Time Frame: Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
The number of subjects that reported hearing the electrical stimulus (if at all)
Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
Tactile Feedback
Time Frame: Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
The number of subjects that reported feeling the electrical stimulus (if at all)
Immediately after electrical stimulation procedure (approximately 1 min after stimulation)
Change in Short Term Relief of Tinnitus as Measured by the Tinnitus Functional Index
Time Frame: Baseline to 4 months
The Tinnitus Functional Index (TFI) contains eight subscales (domains), of which seven contain 3 items and one contains 4. The possible responses for each item range from 0 (did not interfere) to 10 (completely interfered). The total score is transformed to a scale ranging from 0 (no interference) to 100 (completely interfered with activities).
Baseline to 4 months
Change in Short Term Relief of Tinnitus as Measured by the Visual Analog Scale
Time Frame: Baseline to 4 months
The Visual Analog Scale (VAS) for Numeric Pain Distress was used for this outcome. The VAS is a 11-item questionnaire assessing pain. Using a scale of 0 (no pain) and 10 (unbearable pain). Total scores range from 0 - 110, lower scores indicating lower pain and higher scores indicating greater pain.
Baseline to 4 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Matthew L Carlson, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 4, 2018

Primary Completion (Actual)

August 13, 2024

Study Completion (Actual)

August 13, 2024

Study Registration Dates

First Submitted

November 30, 2017

First Submitted That Met QC Criteria

November 28, 2018

First Posted (Actual)

November 30, 2018

Study Record Updates

Last Update Posted (Estimated)

September 10, 2025

Last Update Submitted That Met QC Criteria

August 20, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • 17-004832
  • PR180961 (Other Grant/Funding Number: Department of Defense)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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