Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07393880

Bimodal Electrical-Sound Stimulation and Auditory Training for Chronic Tonal Tinnitus

This study tests whether pairing non-invasive stimulation of the greater occipital nerve (NITESGON) with an attentionally demanding auditory frequency discrimination training task reduces tinnitus loudness and tinnitus-related distress. One hundred adults with chronic tonal tinnitus will be randomised to one of four groups in a 2×2 factorial design: real versus sham NITESGON and active versus passive listening during auditory stimulation. Participants complete eight sessions across four weeks, with outcomes assessed at baseline, end of treatment, 28 days post-treatment, and 6 months post-treatment.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Tinnitus, Subjective Chronic Tinnitus Ear Diseases Hearing Disorders Nervous System Diseases Neurologic Manifestations Otorhinolaryngologic Diseases Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Tinnitus

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

This is a single-centre, prospective, double-blind, placebo-controlled, 2×2 factorial randomised controlled trial conducted at Trinity College Dublin. The intervention combines transcutaneous electrical stimulation targeting the greater occipital nerve (NITESGON) with auditory stimulation delivered during a structured training paradigm. The two between-subjects factors are stimulation condition (real NITESGON vs sham NITESGON) and listening condition (active listening: auditory frequency discrimination training vs passive listening: visual distractor task while auditory stimuli are presented). One hundred adults with chronic tonal tinnitus will be randomised 1:1:1:1 to one of four arms. Participants complete eight sessions (two per week for four weeks). Primary outcomes-tinnitus loudness (VAS 0-100), tinnitus-related functional impact (TFI 0-100), and tinnitus handicap (THI 0-100)-and secondary outcomes are assessed at baseline (T0), end of treatment (T1), 28 days after treatment completion (T2), and 6 months after treatment completion (T3). Secondary outcomes include tinnitus psychoacoustics, extended high-frequency audiometry, speech-in-noise performance, EEG (resting-state and auditory oddball), autonomic/biomarker measures (pupillometry, heart rate, saliva), patient global impression of change, quality of life, and safety/blinding assessments.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 18-80 years
  • Continuous subjective tinnitus for >3 months and ≤5 years
  • Predominantly tonal tinnitus (unilateral or bilateral)
  • Screening THI score 28-76
  • Minimum Masking Level (MML) 20-80 dB HL
  • No prior tinnitus neuromodulation treatment
  • Able to comply with eight sessions over four weeks and follow-up assessments

Exclusion criteria

  • Objective tinnitus or predominantly somatic tinnitus
  • Pulsatile tinnitus
  • Evidence of conductive hearing loss (abnormal otoscopy or tympanometry)
  • Pure-tone audiometry exclusions: >40 dB HL at any frequency 250 Hz-1 kHz OR >80 dB HL at any frequency 2-8 kHz in either ear
  • Hearing aid use initiated within the past 90 days
  • Active implantable medical device (e.g., pacemaker, DBS, cochlear implant)
  • LDL <30 dB SL at 500 Hz in either ear
  • Diagnosis of temporomandibular joint disorder or occipital neuralgia
  • Severe anxiety (STAI >120/160)
  • Cognitive impairment (MMSE <25)
  • Severe depressive symptoms (BDI ≥30)
  • Diagnosis of Menière's disease
  • Current pregnancy
  • Involvement in medicolegal cases
  • History of auditory hallucinations
  • Current prescription of central nervous system drugs likely to alter neuromodulatory function (e.g., noradrenergic, dopaminergic, serotonergic, benzodiazepine, cholinergic, or other psychoactive medications)
  • Currently enrolled in another interventional study

Treatment and study plan

Real NITESGON

Device

Real NITESGON is delivered transcutaneously via two saline-soaked sponge electrodes (35 cm² each) positioned bilaterally over the C2 dermatomes to target the greater occipital nerve. Stimulation consists of a 20 Hz sinusoidal current at 1.5 mA peak-to-peak, ramped up over 30 seconds and ramped down over 5 seconds. It is administered concurrently with the task for ~45 minutes per session, across eight sessions (2/week) over 4 weeks.

Sham NITESGON

Device

Sham NITESGON is delivered using two saline-soaked sponge electrodes (35 cm² each) positioned bilaterally over the C2 dermatomes. The sham condition mimics real stimulation sensations via a 30-second ramp-up followed by a brief ramp-down, with no sustained current thereafter. Sham is administered concurrently with the task for ~45 minutes per session, across eight sessions (2/week) over 4 weeks.

Active Listening

Behavioral

ADT is delivered using a three-interval, three-alternative forced-choice (3I-3AFC) frequency discrimination task. Standard tone frequencies are individually selected using ERB/critical-band spacing, centered one octave below each participant's dominant tinnitus pitch and extending to lower frequencies; the highest standard is kept below the tinnitus pitch region. Tones are presented binaurally via headphones, with presentation levels calibrated to individual audiometric thresholds and matched for equal SPL in both ears.

Other names: Auditory frequency discrimination training (ADT)

Passive Listening (Control)

Behavioral

VisDT uses a three-interval, three-alternative forced-choice (3I-3AFC) paradigm with Gabor patches (sinusoidal gratings windowed by a Gaussian envelope) of fixed spatial frequency (6 cycles/degree) and fixed spatial spread; on each trial, one interval contains an orientation deviant relative to the standard. During VisDT, participants attend to the visual task while concurrent binaural tones are presented passively using a predetermined, non-adaptive schedule. Auditory tones are individually calibrated to audiometric thresholds and drawn from ERB-spaced frequencies centered one octave below the dominant tinnitus pitch and extending to lower frequencies, with the highest frequency kept below the tinnitus pitch region.

Other names: Visual distractor task (VisDT)

Primary outcomes

  1. Tinnitus Loudness (Visual Analogue Scale, VAS 0-100)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    0-100 mm VAS anchored from "not audible" to "extremely loud"; higher scores indicate greater perceived tinnitus loudness.

  2. Tinnitus Functional Index (TFI, 0-100)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    25-item self-report measure of tinnitus-related functional impact; total score 0-100, higher scores indicate greater impairment.

  3. Tinnitus Handicap Inventory (THI, 0-100)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    25-item measure of tinnitus-related handicap; total score 0-100, higher scores indicate greater handicap.

Secondary outcomes

  1. Audiometry (Extended High-Frequency Thresholds up to 13 kHz)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Air-conduction pure-tone audiometry thresholds will be measured from 250 Hz up to 13 kHz (extended high-frequency audiometry) to characterise hearing status and support calibration of stimulus sensation levels.

  2. Speech-in-Noise Performance (e.g., QuickSIN)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Speech perception in noise will be assessed using a standardised speech-in-noise test administered in a controlled environment.

  3. Patient Global Impression of Change (PGIC)

    Time frame: End of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Participant-rated global change since baseline using the Patient Global Impression of Change (PGIC) scale (-3 = very much worse to +3 = very much improved; higher scores indicate greater improvement).

  4. Quality of Life (World Health Organization Quality of Life-BREF questionnaire)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Quality of life assessed using the World Health Organization Quality of Life-BREF (WHOQOL-BREF), yielding domain scores and an overall score (0-100; higher scores indicate better quality of life).

  5. Adverse Events (Stimulation Side-Effects Questionnaire)

    Time frame: Up to 4 weeks (Sessions 1-8)

    Stimulation tolerability assessed each visit using a Stimulation Side-Effects Questionnaire recording presence and severity of side effects (e.g., tingling, itching, headache) rated on a numeric severity scale (0-10; higher scores indicate worse side effects), plus event frequency.

  6. Tinnitus Pitch Matching

    Time frame: Baseline, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Dominant tinnitus pitch estimated by psychoacoustic pitch matching and recorded as frequency in hertz (Hz).

  7. Tinnitus Loudness Matching and Discomfort Levels

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Loudness matching and discomfort levels: Tinnitus loudness matching recorded in decibels sensation level (dB SL; dB above audiometric threshold) at the matched frequency, and loudness discomfort levels recorded in decibels sensation level (dB SL; dB above threshold) at tested frequencies.

  8. Minimum Masking Level (MML)

    Time frame: Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.

    Broadband noise level required to fully mask tinnitus, recorded in decibels hearing level (dB HL).

  9. Resting-State EEG Spectral Power (Eyes Closed)

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Resting-state eyes-closed electroencephalography (EEG) spectral power averaged within prespecified frequency bands and electrode/network regions, reported in decibels (dB); higher values indicate greater spectral power.

  10. Resting-State EEG Functional Connectivity (Eyes Closed)

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Resting-state eyes-closed EEG functional connectivity within prespecified networks, quantified as phase-locking value (PLV; unitless, 0-1); higher values indicate stronger phase synchronization.

  11. Auditory Oddball Task-Evoked Response Amplitude

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Auditory oddball event-related potential (ERP) amplitude (e.g., P300) averaged over prespecified electrodes/time windows, reported in microvolts (µV); higher absolute amplitude indicates larger task-evoked response.

  12. Auditory Oddball Task-Evoked Response Latency

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Auditory oddball ERP component latency (e.g., P300 peak latency) within prespecified time windows, reported in milliseconds (ms); lower values indicate faster evoked responses.

  13. Pupillometry

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Task-related pupil diameter during pupillometry, summarized as mean (or peak) pupil size change from baseline, reported in millimeters (mm); larger values indicate greater pupil dilation.

  14. Heart Rate

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Electrocardiography (ECG)-derived heart rate, reported in beats per minute (bpm); higher values indicate faster heart rate.

  15. Saliva Biomarkers

    Time frame: Baseline visit, end of treatment (4 weeks), 28 days post-treatment, and 6 months post-treatment.

    Concentration of prespecified salivary biomarkers of arousal/neuromodulatory engagement, reported in nanograms per milliliter (ng/mL) (or assay-specific units); higher values indicate higher biomarker concentration.

Study contacts

Contact information is provided by the study sponsor or research team.

Anusha Mohan, PhD

CONTACT

[email protected]

Sven Vanneste, PhD

CONTACT

[email protected]

+353 87 470 2835.

Sponsors and collaborators

Lead sponsor

University of Dublin, Trinity College

Other

Registry information

Official study title

Non-Invasively Re-Training the Tinnitus Brain Using Bimodal Electrical-Sound Stimulation (NITESGON-ADT): Protocol for a Prospective, Double-Blind, Randomised Controlled Trial

Acronym: NITESGON-ADT

Important dates

Study start
2026
Primary completion
2028
Study completion
2029
First posted
Feb 6, 2026
Registry last updated
Apr 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.