Background: Hospital in-patients need sleep so that restorative process and healing can take place. However, over one third of in-patients experience sleep disturbance, often caused by noise. This can compromise patients’ perceptions of care quality and cause physical and psychological ill health. Aims: To assess 1) in-patients sleep quality, quantity, reported sources of sleep disturbance and their suggestions for improvement 2) objectively measure decibel levels recorded at night. Methods: This descriptive study conducted in a Medical Assessment Unit used multi-methods; a semi-structured ‘sleep experience’ questionnaire administered to a purposive sample of in-patients; recording of night-time noise levels, on 52 consecutive nights, using two calibrated Casella sound level meters. Results: Patient ratings of ‘in-hospital’ sleep quantity (3.25; 2.72 SD) and quality (2.91; 2.56 SD) was poorer compared to ‘home’ sleep quantity (5.07; 2.81 SD) and quality (5.52; 2.79 SD). The difference in sleep quality (p<0.001) and quantity (p<0.001) ratings whilst in hospital, compared to at home, was statistically significant. Care processes, noise from other patients and the built environment were common sources of sleep disturbance. Participants’ suggestions for improvement were similar to interventions identified in current research. The constant noise level ranged from 38-57 decibels (equivalent to an office environment), whilst peak levels reached a maximum of 116 decibels, (equivalent to banging a car door one metre away). Conclusion: The self-rated patient sleep experience was significantly poorer in hospital, compared to home. Noise at night contributed to sleep disturbance. Decibel levels were equivalent to those reported in other international studies. Data informed the development of a ‘Sleep Smart’ toolkit designed to improve the in-patient sleep experience.