Songbird Alarm — how the waking works
Why does it begin at a volume you can barely hear? Here is the thinking behind it, and the research it came from.
The idea behind this alarm
When a loud sound drags you out of deep sleep, your head can stay foggy for a long time afterwards — what is called sleep inertia.
This app starts the birdsong of the forest at your wake-up time, at a volume you can barely hear, and raises it a little at a time over about 15 minutes. The moment your sleep grows light, even a quiet sound reaches you and you wake by yourself. The design is built around waiting for that moment.
At the end, a Japanese bush warbler calls clearly, so that you do wake.
How deeply you sleep changes what you can hear
Sleep research has confirmed, again and again since the 1960s, that the quietest sound able to wake you — the auditory awakening threshold — differs greatly between the stages of sleep.
In deep sleep (slow-wave sleep), the brain does not respond unless the sound is quite loud. In light sleep and REM sleep, a quiet sound is enough.
Across a night, sleep moves between deeper and lighter, in cycles of roughly 90 minutes. So the thinking is this: play a quiet sound and raise it slowly, and you are likely to wake when your sleep has turned light, and to sleep on while it is deep.
The kind of sound matters too
A study published in 2020 (RMIT University, Australia) reported that people woken by a sound with a melody had less grogginess just after waking than people woken by a flat, repeating beep.
Birdsong has pitch and rise and fall, and it is a sound we have heard all our lives in connection with morning. That is one reason this app chose it.
Getting the most out of it
- Set your iPhone’s device volume to 70–80%. The beginning stays faint, and the warbler at the end comes through clearly
- Set the wake-up time to 15 minutes before the time you want to be up (the warbler calls about 15 minutes in)
- For the night sounds — the forest at midnight, a night of rain, bell crickets — the right volume is one where, while you are still awake, you can only just hear it in the room
What we want to say plainly
The research above is research on sleep and sound.
It did not test this app’s way of waking you. There is, at present, no study proving that this method will always wake you pleasantly. We built this shape from what is generally established, and no more.
This app is not a medical device, and it does not promise to improve your sleep or your health. If you have concerns about your sleep, please speak to a doctor.
References
- Williams HL, Hammack JT, Daly RL, Dement WC, Lubin A. Responses to auditory stimulation, sleep loss and the EEG stages of sleep. Electroencephalography and Clinical Neurophysiology. 1964;16:269–279.
- Rechtschaffen A, Hauri P, Zeitlin M. Auditory awakening thresholds in REM and NREM sleep stages. Perceptual and Motor Skills. 1966;22:927–942.
- Bonnet MH, et al. Sleep stages, auditory arousal threshold, and body temperature as predictors of behavior upon awakening. International Journal of Neuroscience. 1985;27:19–29.
- McFarlane SJ, Garcia JE, Verhagen DS, Dyer AG. Alarm tones, music and their elements: Analysis of reported waking sounds to counteract sleep inertia. PLOS ONE. 2020;15(1):e0215788.