---

Background and purpose: Coma results from brain damage and patients in intensive care units (ICU) are often more at risk for sensory deprivation. This study compares the effects of familiar and unfamiliar voices on recovering the consciousness level in comatose patients. Materials and methods: This double blind clinical trial (patient and assessor) was performed in 45 traumatic comatose patients with Glasgow Coma Scale (GCS) ≤8 within the age range of 15-75 years, admitted to ICU training centers affiliated to Mazandaran University of Medical Sciences. The subjects were randomly allocated into three groups. Group A was stimulated with a familiar voice, group B’s auditory stimulation was done by the researcher introduced as a nurse) and no intervention was done for group C (control group). The interventions were conducted twice a day for 1-5 minutes. The level of consciousness was measured using the GCS scale. To analyze the data descriptive and inferential statistics (Logrank Test) were used. Results: In the day before the intervention the mean levels of GCS in groups A, B, and C were 6.40, 5.66, and 5.53, respectively. Logrank test revealed significant differences between the groups in the time to reach CGS= 15 which happened sooner in group A (P<0.0001). Conclusion: Familiar voice could highly influence the auditory level of patients in ICU. Therefore, auditory stimulation programs are recommended for comatose patients.