Bimodal Electrical-Sound Stimulation and Auditory Training for Chronic Tonal Tinnitus
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-80
SponsorUniversity of Dublin, Trinity College
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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
Trial design
Design model
Factorial
Treatments tested in this trial
Real NITESGON
DeviceReal 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
DeviceSham 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
BehavioralADT 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.
Passive Listening (Control)
BehavioralVisDT 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.
Treatment groups
100 Participants
are divided into 4 treatment groupsGroup A: Real Stimulation + Active Listening (ADT)Experimental treatment 2 interventions
Group B: Real Stimulation + Passive ListeningActive comparator 2 interventions
Group C: Sham Stimulation + Active Listening (ADT)Sham comparator 2 interventions
Group D: Sham Stimulation + Passive ListeningSham comparator 2 interventions
Trial outcomes
Primary outcomes
1
Tinnitus Loudness (Visual Analogue Scale, VAS 0-100)
0-100 mm VAS anchored from "not audible" to "extremely loud"; higher scores indicate greater perceived tinnitus loudness.
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.2
Tinnitus Functional Index (TFI, 0-100)
25-item self-report measure of tinnitus-related functional impact; total score 0-100, higher scores indicate greater impairment.
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.3
Tinnitus Handicap Inventory (THI, 0-100)
25-item measure of tinnitus-related handicap; total score 0-100, higher scores indicate greater handicap.
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.Secondary outcomes
1
Audiometry (Extended High-Frequency Thresholds up to 13 kHz)
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.
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.2
Speech-in-Noise Performance (e.g., QuickSIN)
Speech perception in noise will be assessed using a standardised speech-in-noise test administered in a controlled environment.
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.3
Patient Global Impression of Change (PGIC)
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).
Time frame
End of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.4
Quality of Life (World Health Organization Quality of Life-BREF questionnaire)
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).
Time frame
Baseline visit, end of treatment at 4 weeks, 28 days post-treatment, and 6 months post-treatment.Sponsors and contacts
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Source ClinicalTrials.gov