Sources & how to read the evidence

This guide was built from the primary literature — clinical guidelines, Cochrane reviews, randomised trials, and regulatory documents — and graded by how strong the evidence actually is. Where a field is thin or a product is hyped (nattokinase-style supplement claims, 'cure' devices), it says so and shows both sides rather than picking one.

How it was built

The approach: Every load-bearing claim comes from a named guideline, trial, Cochrane review, or regulatory document, with the evidence dots (●●●●● = strong and replicated, down to ○○○○○ = essentially unproven) reflecting study design, size, and replication. Figures are group averages; individuals vary widely. This is educational, not a diagnosis or a prescription.
The key sources: Diagnosis, what-to-do and what-not-to-do: the AAO-HNS Clinical Practice Guideline (Tinnitus, 2014) and NICE NG155 (2020). The emergency: the AAO-HNS Sudden Hearing Loss guideline (2019). Mechanisms & burden: the central-gain and Jastreboff neurophysiological models, and the global prevalence meta-analysis (Jarach et al., JAMA Neurology 2022). Best-evidenced treatment: the Cochrane review of CBT (Fuller et al. 2020), the TRTT trial for TRT, and the Cochrane sound-therapy review. Drugs: the Cochrane reviews of betahistine, antidepressants, and anticonvulsants. Neuromodulation: Lenire's FDA De Novo authorization (2023) and the TENT-A trials, and the Shore/Michigan bimodal trial (2023). Supplements: the Cochrane reviews of ginkgo and zinc, and the AAO-HNS recommendation against supplements.

Educational reference — not medical advice

This guide summarises published research for general education. It is not a diagnosis, a prescription, or a substitute for care. Act on the red flags urgently — sudden hearing loss is an emergency — get properly assessed with a hearing test, and never start, stop, or change any medication on your own. Decide anything here with a qualified clinician who knows your history.

The Tinnitus Guide