The Effects of Familiar Voices on the Level of Consciousness among Comatose Patients: A Single-Blind Randomized Controlled Trial

Background: Brain injury can reduce consciousness and the ability to respond to environmental stimulation. Objectives: The aim of this study was to investigate the effects of familiar voices on the level of consciousness (LOC) among comatose patients with a brain injury hospitalized in the intensive care unit. Methods: In this randomized controlled trial, sixty comatose patients with head trauma were conveniently selected from an intensive care unit of a hospital in Rasht, Iran, and randomly allocated to either a control or an intervention group. Participants in the intervention group received auditory stimulation for three consecutive days and the level of consciousness was compared in two groups. The Glasgow Coma Scale was used to assess the patients' level of consciousness. The data were analyzed through the Chi-square, the paired-samples t, student's t test, and the repeated-measures analysis of variance. Results: A significant increase was found in the mean LOC in the intervention group after every daily auditory stimulation (P<0.05). However, no significant changes were observed in the control group (P>0.05). The repeated-measures analysis of variance revealed that the time and interaction of time and groups were statistically significant (P<0.001). Conclusion: Auditory stimulation with familiar voice was effective in improving levels of consciousness among comatose patients with a brain injury after three days.