5TRT — The Sound Therapy Component

FSound enrichment, not masking

The most common misunderstanding about TRT is that the sound is there to hide the tinnitus. It is not. The aim is the opposite: the patient should still be able to hear their tinnitus alongside the added sound, because habituation can only happen to a signal the brain is still receiving [1993].

Low-level neutral sound — typically broadband noise — reduces the perceptual contrast between the tinnitus and a silent background. In silence, the brain turns up its internal gain and the phantom signal becomes prominent; gentle background sound prevents that and lets tinnitus blend into the soundscape [2013].

TThe mixing point

The key clinical setting is the ‘mixing point’: the sound level at which the external noise and the tinnitus just begin to blend together, so that the patient perceives them as merging without the noise covering the tinnitus completely. The device is deliberately set below the level that would mask the tinnitus [1990].

Why partial rather than total? Total masking removes the signal the brain is supposed to be learning to ignore, so habituation stalls. Partial enrichment keeps the tinnitus audible but no longer dominant, giving the auditory and limbic networks repeated, low-stakes exposure that drives neuroplastic adaptation [2014].

CDoes total masking matter? The evidence

The mixing-point doctrine has been tested directly. A randomised comparison by Tyler and colleagues found that, in practice, setting wearable sound generators to the mixing point versus to total masking produced equivalent outcomes — suggesting the precise level is less critical than consistent daily sound enrichment combined with counselling [2012].

This nuance matters clinically: rather than agonising over an exact decibel setting, the clinician should ensure the patient finds the sound comfortable enough to wear for many hours a day, which is the true rate-limiting step for habituation [2014].

TWearable sound generators

Dedicated wearable sound generators are small ear-level devices, resembling hearing aids, that emit steady low-intensity broadband noise — often white, pink, or filtered noise shaped to the patient. They suit patients with normal or near-normal hearing in whom amplification is unnecessary [1993].

The sound must be calibrated individually: comfortable, non-intrusive, and emotionally neutral, because any sound the patient finds irritating defeats the purpose by adding a second aversive signal. For patients with hearing loss, hearing aids or combination devices deliver the same enrichment while also restoring useful sound — covered in later modules [2013].

CDaily wear and the time course

Sound therapy works through accumulated exposure, so adherence is everything. The conventional target is several hours of daily use — commonly cited as on the order of six to eight hours — sustained across many months, with environmental sound enrichment filling the gaps so the patient is rarely exposed to true silence [2006].

Because the benefit is gradual and unfolds over roughly 12–24 months, counselling and sound therapy are inseparable: the patient must understand why they are wearing a device that does not silence their tinnitus, or they will stop wearing it [2019].