Auditory Stimulation May Aid Consciousness Recovery, Evidence Remains Weak

A pooled analysis of fifteen randomized controlled trials suggests that auditory sensory stimulation was associated with higher Glasgow Coma Scale scores and a lower postintervention pulse rate than control conditions in patients with disorders of consciousness. The systematic review and meta-analysis, published in Frontiers in Neuroscience, pooled postintervention data from 713 patients and expressed effects as mean differences with 95 percent confidence intervals. However, the authors caution that the certainty of this evidence, graded with the GRADE framework, was low for consciousness outcomes and very low for every physiological measure examined.

The reviewers searched six databases from inception to April 25, 2026 and followed PRISMA reporting guidelines.

The pooled estimates showed no statistically significant between-group differences in systolic blood pressure, diastolic blood pressure, respiratory rate, oxygen saturation, or body temperature. Only the pulse rate differed, and the authors emphasize that confidence in all physiological findings is very low.

To probe why trials disagree, the team organized subgroup comparisons around the FITT framework, which describes interventions by frequency, intensity, time, and type of stimulation. The exploratory analyses revealed numerical differences in effect estimates across some intervention categories, but the authors explicitly state that these patterns did not establish an optimal intervention protocol. Univariable random-effects meta-regression analyses likewise identified no statistically significant study-level moderators, meaning no measured characteristic of the trials reliably explained the heterogeneity in results.

The authors' conclusion is cautious. Auditory sensory stimulation may have potential as an adjunctive rehabilitation intervention for patients with disorders of consciousness, but confidence in its effect on Glasgow Coma Scale scores is limited by the low certainty of the evidence, and its effects on physiological outcomes remain highly uncertain. The available data are insufficient to prescribe how often, how loudly, how long, or in what form stimulation should be delivered.

The authors point to specific gaps that future trials should close. The authors conclude that future high-quality randomized controlled trials using standardized auditory SS protocols, comprehensive reporting of stimulation parameters (particularly stimulation intensity), and consistent outcome measures are needed to establish the optimal FITT prescription for auditory sensory stimulation.

Subject of Research: A systematic review and meta-analysis of auditory sensory stimulation for patients with disorders of consciousness

Article Title: Effects of auditory sensory stimulation on consciousness and physiological parameters among individuals with disorders of consciousness: a systematic review and meta-analysis

Article References: Zhang, J., Yan, X., Huang, F., Huang, Y., Wang, J., Zhang, Y., & Taniguchi, T. (2026). Effects of auditory sensory stimulation on consciousness and physiological parameters among individuals with disorders of consciousness: a systematic review and meta-analysis. Frontiers in Neuroscience, 20, Article 1879145. https://doi.org/10.3389/fnins.2026.1879145

Image Credits: AI Generated

DOI: 10.3389/fnins.2026.1879145

Keywords: auditory sensory stimulation, disorders of consciousness, meta-analysis, Glasgow Coma Scale, physiological parameters, FITT framework, GRADE certainty, randomized controlled trials, rehabilitation, PRISMA, Effects, auditory