Tinnitus
Conditions
Keywords
Tinnitus, 40 Hz stimulation, Acoustic therapy, Residual inhibition, Personalized medicine
Brief summary
Tinnitus affects 10-15% of adults and is frequently associated with impaired quality of life, anxiety, and sleep disturbance. Conventional sound therapies based on continuous masking provide inconsistent and short-lived relief, and the neural mechanisms underlying residual inhibition (RI) remain unclear. This study aims to determine whether 40 Hz burst stimulation with high-frequency carriers can achieve longer-lasting RI than continuous sound, and to explore its underlying neural mechanisms using EEG.
Detailed description
Residual inhibition (RI) refers to the temporary reduction or disappearance of tinnitus following sound stimulation and provides an important clue for identifying patients who may benefit from acoustic therapy. However, the effects of different sound stimulation strategies on RI remain poorly understood. This study evaluates whether 40 Hz burst-modulated sound achieves stronger and longer RI compared with conventional continuous stimulation. The trial follows a four-phase design: Phase 1: Exploratory testing of burst versus continuous tones at different frequencies. Phase 2: Large-scale validation in 265 patients. Phase 3: Development of a personalized stimulation protocol using adaptive spectral optimization. Phase 4: EEG investigation of neural mechanisms, focusing on gamma oscillations and functional connectivity changes. The primary outcomes are the strength and duration of tinnitus suppression. Secondary outcomes include EEG markers such as γ-band power spectral density and phase-locking value. By combining behavioral and neurophysiological measures, this study aims to establish 40 Hz burst stimulation as a novel rhythm-based sound therapy and to provide mechanistic insights that may enable more effective, personalized tinnitus management.
Interventions
OTHERPersonalized 40 Hz Broadband Stimulation
Broadband acoustic stimulus (125 Hz-12 kHz) amplitude-modulated at 40 Hz with a 50% duty cycle. A polynomial regression and FFT-based algorithm applies individualized frequency weighting, combining population data (70%) and patient-specific responses (30%). Delivered for 60 seconds at 10 dB above the individual minimum masking level (MML).
OTHER40 Hz Pure Tone Stimulation
Pure tone stimulus at the optimized frequency (matched to tinnitus characteristics or high-frequency carrier), amplitude-modulated at 40 Hz with a 50% duty cycle. Delivered for 60 seconds at 10 dB above MML.
OTHERContinuous Broadband Noise
Continuous broadband noise spanning 125 Hz-12 kHz without 40 Hz modulation. Delivered for 60 seconds at 10 dB above MML as an active control condition.
Sponsors
Eye & ENT Hospital of Fudan University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
1. Diagnosed with subjective tinnitus; 2. Chronic tinnitus: tinnitus course ≥ 1 month; 3. Normal middle ear function; 4. The average hearing threshold (defined as mean of 0.5, 1, 2, and 4 kHz) of the unaffected ear \< 60 dB; 5. Tinnitus can be heard under normal circumstances. 6. Subjects are able to understand the purpose of the study, volunteer to participate and cooperate with the instructors to complete the experiment, and be willing to sign the informed consent.
Exclusion criteria
1. Acute phase tinnitus; 2. Fluctuating tinnitus loudness; 3. Severe psychiatric disorders; 4. Inability to complete tinnitus testing; 5. Fluctuating or retrocochlear hearing loss; 6. Conductive hearing loss; 7. Currently participating in other research projects that may affect tinnitus; 8. Subjects who are not considered suitable for this clinical trial by the researchers.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Tinnitus suppression strength | Immediately after the sound stimulation session. | Residual inhibition depth, 0-100% reduction |
| Residual inhibition duration | Immediately after the sound stimulation session. | Time in seconds until tinnitus returns to baseline after stimulation |
Secondary
| Measure | Time frame |
|---|---|
| EEG spectral power changes | measured across the entire 10-minute EEG recording session (baseline, during stimulation, and post-stimulation) |
| EEG functional connectivity changes | measured across the entire 10-minute EEG recording session (baseline, during stimulation, and post-stimulation) |
Countries
China
Outcome results
None listed