In medieval Europe, the word “lullaby” emerged from the soothing repetition of “lullen” (to lull) and “bye-bye,” while a more mystical theory links it to the Hebrew phrase “Lilith-Abi”—a protective incantation to keep demons at bay.
Fast-forward to today, and the impulse to use music as a sleep aid has taken on a technological dimension.
Sleep disorders are increasingly present among young people, with recent data highlighting their significance. In 2022, 64% of individuals aged 17 to 23 in England reported experiencing sleep problems on three or more nights in the previous week.
Professor Renee Timmers, a music psychologist at the University of Sheffield, is one of the figures leading this transformation. Her journey into the science of sleep music began through an unexpected collaboration.
“A colleague from the Management School introduced me to Braintrain2020, the company behind SleepCogni,” she explains. “They were interested in integrating music into their sleep technology, and that’s how our research partnership began.”
Together with Dr Rory Kirk, Timmers investigated the effects of bedtime music on sleep quality. Though in the beginning their research didn’t show that music significantly speeds up the process of falling asleep. It did reveal that it can improve how people perceive and experience their sleep.
“The music enhances mood, reduces anxiety, and provides comfort,” she says. “That emotional shift makes a big difference.”
The key lies in both the structure of the music and the listener’s personal response to it. Sleep-inducing tracks often feature slow tempos (60–80 beats per minute), minimal dynamic changes, and simple, repetitive patterns.
Lyrics are generally avoided, as they stimulate cognitive processing that may keep the brain alert. But Timmers’ research suggests that the emotional resonance of music, whether it feels comforting or mind-freeing, is often a stronger indicator of its effectiveness than tempo or physical qualities alone.
This opens the door to a fascinating area of development: personalised sleep music. Technology is stepping in to tailor auditory experiences to the individual. Apps like Endel use artificial intelligence to generate adaptive soundscapes based on physiological data, such as heart rate and circadian rhythms.
These dynamic compositions respond to the user in real time, creating a personalised lullaby that can shift with the listener’s state of mind and body.
If tech takes your fancy:
BrainTrainUK, a neurofeedback therapy provider, is taking a similar approach but from a neurological perspective. By measuring brainwave activity with EEG, they help users learn to regulate their mental states through audio feedback, training the brain into patterns associated with rest and recovery.
SleepCogni, a Sheffield-based company working with Professor Timmers, has created a handheld device designed to help people with insomnia. The device gently uses light, sound, and vibration to interrupt racing thoughts that can keep someone awake at night.
It collects information about the person’s body and surroundings—like their heart rate or room temperature—to make the treatment more personal and effective. SleepCogni is now working with Sheffield Children’s NHS Foundation Trust to test how well the device works, especially for children, where support services are often limited.
As Dr Maan van de Werken, Chief Scientific Officer at SleepCogni, puts it, “Industry-led research in the insomnia space holds great promise to impact many in society. We’re excited to meet the growing sleep challenges facing young people.”
Yet even with all this innovation, one thing hasn’t changed: the emotional power of music. A recent study of Spotify’s most popular sleep playlists showed that, while most feature calming, instrumental tracks, some include surprisingly upbeat pop songs.
The takeaway? Personal association plays a huge role—whether it’s a favourite childhood melody or a relaxing lo-fi beat, what matters most is how the music makes you feel.
For Professor Timmers, that human element is essential. “Music has to strike the right balance,” she says. “It should be emotionally engaging without being mentally demanding. It should draw you in—just enough—and then let you go.”
It seems the future of sleep may not be silent after all. Instead, it might be filled with soft harmonies and precisely engineered lullabies—songs that don’t just help us fall asleep, but help us feel safe doing so.
