Between sound and sleep: a perspective on Sonic Sleep Aids.

Sleep disturbances are prevalent in the general population, coinciding with a surge in the availability and use of digital sleep aids. Among these, standalone audio-based tools, termed Sonic Sleep Aids (SSA), such as sleep music, ambient sounds, bedtime stories, and sleep skills (e.g. guided meditation, positive psychology techniques), have gained popularity. This perspective piece examines the phenomenon of SSA by discussing the existing evidence and highlighting the different levels of empirical support across SSA types. Music-based relaxation has demonstrated efficacy in improving sleep quality, whereas findings on ambient sounds (e.g. white, pink noise) are inconclusive. Empirical support for narrated content as a sleep aid remains limited. Guided practices like mindfulness and self-compassion show potential, yet further research is needed to support their effectiveness, particularly when limited to bedtime practice. In the broader context, the widespread use of app-based SSA raises questions about their alignment with sleep hygiene recommendations, which typically discourage bedtime screen use. This concern is compounded by a paucity of randomized controlled trials testing their effectiveness against well-matched controls, alongside the risk of increased dependency on technology and altered relationships with rest and introspection. Against these concerns, potential benefits include accessibility and reduced reliance on pharmacological aids. A research agenda is proposed to investigate the efficacy of digitally delivered SSA in naturalistic settings, their mechanisms of action, and their impact across different populations. Understanding these factors is crucial to determine whether SSA serve as beneficial tools or divert individuals from more effective, evidence-based approaches to sleep.