Low-intensity noise therapy shows how tuning sound to the brain can ease tinnitus

By Tarun Sai LomteReviewed by Susha Cheriyedath, M.Sc.Nov 16 2025

A tailored low-intensity noise stimulus alleviated tinnitus symptoms in a Phase II trial, demonstrating promise for a non-masking, precision-based sound therapy that quiets the brain’s internal noise.

Study: Phase II Clinical Study on Low-Intensity-Noise Tinnitus Suppression (LINTS) for Tinnitus Treatment. Image Credit: l i g h t p o e t / Shutterstock

In a recent study published in the journal Brain Sciences, researchers investigated the effects of low-intensity noise tinnitus suppression in a phase II clinical trial of tinnitus treatment. Hearing loss is believed to cause subjective tinnitus, meaning sound perception occurs without an external source.

In Germany, the estimated socioeconomic burden of tinnitus and its related comorbidities has been modelled at approximately €22 billion per year, largely driven by productivity losses and mental-health impacts. Tinnitus treatment is typically limited to counseling and coping strategies, as its neurophysiological mechanisms remain poorly defined.

The authors previously proposed a novel therapeutic strategy, low-intensity noise tinnitus suppression, and demonstrated its potential in proof-of-concept studies. In this approach, internal neuronal noise that is perceived as tinnitus is replaced with an external low-intensity acoustic noise matched to the patient’s hearing threshold and tinnitus frequency.

The stimulus is non-masking, delivered at threshold-level intensity, and often barely audible or not consciously perceived. This design distinguishes low-intensity noise tinnitus suppression from conventional masking, which employs louder noise to mask tinnitus rather than modulate neural activity.

Participant Selection and Eligibility Criteria

In the present study, researchers evaluated the effects of continuous low-intensity noise tinnitus suppression in a placebo-controlled Phase II clinical trial. The study included 84 adults with tinnitus; eligible participants were those with narrowband or tonal tinnitus perception and sufficient proficiency in the German language.

Individuals using hearing aids, with a mini-tinnitus questionnaire severity index greater than three, tinnitus frequency above 10 kHz, or hearing loss greater than 40 dB below 8 kHz were excluded. Patients with extremely severe tinnitus were also not enrolled, resulting in a cohort with mild to moderate symptom severity.

The authors note that this intentionally restricted population may not reflect outcomes in individuals with more severe tinnitus or more pronounced hearing loss.

Randomization and Treatment Protocol Design

Participants were divided into two groups: the low-intensity noise treatment-only group and the placebo plus treatment group. The treatment-only group received immediate low-intensity noise stimulation for four weeks. The placebo plus treatment group received white noise stimulation for two weeks before switching to low-intensity noise stimulation for four additional weeks.

The tinnitus health and tinnitus sample case history questionnaires were administered before treatment. Air conductance hearing thresholds, tinnitus loudness, and tinnitus frequency were measured. Optimal low-intensity noise was identified by presenting narrowband noise around the perceived tinnitus frequency; the noise producing the greatest soothing effect was chosen.

Fitting was technically challenging, and narrowband tuning was not always achievable due to the limitations of the hearing aids. Some patients received wideband noise because of device constraints, while others received more precise narrowband noise, contributing to variable responses.

Device Use and Stimulation Delivery Methods

Hearing aids were applied only to ears affected by tinnitus, and their amplification function was not activated. Low-intensity noise was delivered using the device’s internal noise generator or a Bluetooth-coupled iPod. An in-house computer program generated the appropriate stimulation for both treatment groups.

Patients were asked to wear the hearing aids for at least four hours per day, five days a week. The Tinnitus Health Questionnaire was administered during treatment and four weeks after treatment cessation.

Because this instrument measures longer-term burden, it may be less sensitive to short-term changes; however, repeated assessments every two weeks help mitigate this limitation. Initial hearing loss profiles of the groups were compared using analysis of variance. Changes in tinnitus loudness and tinnitus frequency over time were analyzed using the Wilcoxon and Mann-Whitney U tests, and non-parametric approaches were employed to assess tinnitus health questionnaire scores and sub-scores.

Treatment Outcomes in Tinnitus Severity Measures

In total, 72 of 84 patients completed the study. Of these, 24 were in the placebo plus treatment group and 48 were in the treatment-only group. Hearing aid wearing time was high and comparable between groups. Age, gender, and tinnitus characteristics were not significantly different.

The median baseline tinnitus health questionnaire score was 28 in the treatment-only group and 21.5 in the placebo plus treatment group. There was a slight but significant difference in average hearing loss, with the placebo plus treatment group and treatment-only group showing a 17.9 dB and 14.6 dB deficit, respectively.

Clinically relevant hearing loss greater than 20 dB was observed at frequencies above or equal to 3 kHz. Tinnitus frequency distributions did not differ between groups. A significant temporal reduction in Tinnitus Health Questionnaire scores was observed only in the treatment-only group.

Temporal Patterns of Symptom Improvement

This temporal effect appeared two weeks after treatment, peaked at four weeks, and remained significantly lower for up to four weeks after treatment cessation. Improvements were statistically significant but modest, with wide inter-individual variation.

For patients receiving placebo plus treatment, the two-week exposure to white noise appeared to mitigate the effect of low-intensity noise. The authors suggest that this exposure may have been maladaptive rather than neutral. Consistent with this interpretation, no placebo effect was observed in the placebo plus treatment group, and improvements emerged only after switching to low-intensity noise.

One treatment-only patient, a 52-year-old male who initially experienced mild tinnitus, reported complete silencing of his tinnitus while wearing the hearing aid. The individual was more aware of tinnitus when not wearing the device and reported sleep difficulties.

Tinnitus health questionnaire scores decreased by 11.8% and 17.6% at two and four weeks, respectively. Notably, four weeks after treatment cessation, this patient exhibited a 47.1% reduction compared to baseline. Another treatment-only patient, a 42-year-old male with severe tinnitus, experienced marked improvements in tinnitus loudness and used the hearing aids even at night to facilitate sleep.

Clinical Interpretation of Low-Intensity Noise Suppression

The study demonstrated that low-intensity noise tinnitus suppression can significantly reduce tinnitus health questionnaire scores in patients with subjective tinnitus. However, the 12-point improvement considered clinically relevant was not achieved in most individuals.

Most effects were confined to the treatment-only group, reflecting the exploratory nature of the trial and substantial response variability. The authors highlight that therapeutic success depends heavily on the precision of low-intensity noise fitting and the technical capabilities of current devices.

Overall, low-intensity noise tinnitus suppression appears promising for partial or subjectively complete tinnitus suppression. Nevertheless, it requires further optimization and validation before it can be integrated into clinical practice. Future research will require improved precision fitting, enhanced noise-generation hardware, and larger cohorts including individuals with broader tinnitus severity profiles.