Statement of Significance
Poor sleep is pervasive, becoming increasingly prevalent, and has profound personal, social, economic, and public health consequences. Recently, there has been a dramatic increase in the use of app-based audio tools by the public before and during sleeping hours. These interventions are cheap, widely available, easy to use, and unlikely to cause harm, yet there is a lack of evidence regarding their efficacy and underlying mechanisms of action. This study takes the first steps to address this gap in knowledge, and pave the way for further research. We show that two categories of audio tools featured on the Unmind mental health app are both feasible and acceptable, and demonstrate preliminary efficacy across many sleep and mental health outcomes.