LAUSR

With the growth of interest in using music to treat insomnia, there is a need to collect and evaluate the literature. This paper reviews disparate literature and assesses the various kinds of assertions and hypotheses made by researchers about music's efficacy in assisting sleep. Six main researcher proposed reasons (RPR) for how music aids sleep were identified in the literature: (1) relaxation, where music encourages physiological or psychological relaxation; (2) distraction, where music acts as a focal point to distract from inner stressful thoughts; (3) entrainment, synchronization of biological rhythms to beat structures in music; (4) masking, obscuring noxious background noise with music; (5) enjoyment, listening to preferred, emotionally relatable or pleasant music; and (6) expectation, individuals cultural beliefs around music. We evaluated each RPR in terms of the evidence available in the extant literature. Masking RPR was identified as having support for improving sleep. Relaxation, distraction and enjoyment RPR had mixed levels of support. Expectation RPR had possible support. Entrainment had mixed possible support. The paper discusses interactions between RPRs, and a call is made to turn research attention to sequencing the RPRs and possible RPR mediators, with relaxation being a likely mediator of several RPRs.