Most advice about alarm sounds mixes up two different problems. If you sleep straight through your alarm, you need a sound that wakes you. If you wake fine but feel foggy for the next half hour, you want a sound that leaves you clearer. The studies on these are separate, and their answers are not the same.
This summary is written by the developer of Wakr, a mission alarm app. It is not medical advice, and every finding below links to its source at the end.
The short answer
To wake a deep sleeper, a low-pitched, harsh tone beat the usual high-pitched beep by a wide margin in fire-safety research. To feel less groggy, two small studies favour a melodic tone over a plain beat, but the researchers themselves call the evidence preliminary. A gradually louder alarm improved mood in the one direct test, not sleepiness.
Melodic alarms and grogginess
The best-known work comes from a team at RMIT University in Melbourne. In a 2020 survey, 50 people described the alarm sound they had woken to that morning and how groggy they felt. The type of sound, whether beeps, music, or nature sounds, made no measurable difference. How melodic people rated it did: more melodic sounds went with less reported grogginess.
A follow-up the same year split 20 people into two groups of 10 who woke at home to either a melodic alarm or a rhythm-only one, then took a three-minute reaction test. The melodic group had fewer lapses and a better overall score. Their reaction time itself did not change, and neither group felt less sleepy.
Later that year, the team reviewed every adult study they could find on alarm sounds and sleep inertia, the foggy state just after waking. There were 12, and they concluded that the best volume and pitch for an alarm are yet to be determined. A melodic alarm is a reasonable thing to try. It is not a proven fix.
Low tones wake deep sleepers
The strongest evidence about waking people at all comes from smoke-alarm research, which tests whether a sound wakes someone from deep sleep. Researchers at Victoria University in Australia ran a series of experiments with children, deep-sleeping young adults, older adults, adults with hearing loss, and adults who had been drinking. Across them, a 520 Hz square-wave tone, lower and harsher than a standard alarm beep, was at least 4 to 12 times more effective than the usual high-pitched smoke alarm.
Some of the individual results are striking. Among 38 adults with mild to moderately severe hearing loss, the 520 Hz tone woke 92% at 75 decibels, against 56% for the standard 3,100 Hz alarm. A separate US study of 176 children aged 5 to 12 found a similar low tone woke 88% of them, against 49% for the standard high tone.
Keep the limits in mind. These studies measured whether people woke in an emergency, not how groggy they felt, and none tested a phone alarm. Still, if you sleep through high-pitched beeps, a lower, rougher sound is the best-supported thing to try.
Gradually louder alarms
Many apps offer an alarm that starts quietly and grows louder. A 2026 study from KTH Royal Institute of Technology in Stockholm tested one at home: 18 people each spent a week with a gradually rising alarm and a week with a steady version of the same sound. The rising alarm left people in a better mood. It made no clear difference to how sleepy they felt or how well they slept. People took longer to stop it, but they did not snooze more or get up later.
Most of the participants were good sleepers in their twenties, and the rising sound had a standard backup alarm behind it. If you already sleep through alarms, keep a backup when you try a gentle one.
If you do not hear alarms at all
In the hearing-loss study above, bed and pillow shakers woke 80 to 84% of people at their standard setting, and strobe lights woke 27%. If hearing is the issue, vibration under the pillow or mattress is the better-supported option, and a hearing professional can advise on alerting devices.
If you hear the alarm but switch it off without remembering, no sound will fix that, because you already heard it. The guide to sleeping through your alarm covers that case.
Claims you may have read
“Alarms raise your blood pressure by 74%.” This comes from a University of Virginia pilot study of 32 people that has not been published in a journal. The absolute difference was 2.38 mmHg, which the researcher called small, and the alarm nights were also the short-sleep nights, so the two cannot be separated.
“Melodic alarms cure grogginess.” The evidence is one 50-person survey and one 20-person study, and the researchers’ own review says more work is needed.
How to choose your alarm sound
- 1
Work out which problem you have.
Not hearing it, feeling foggy after it, or switching it off without waking. Each needs a different fix.
- 2
If you sleep through it, go lower and rougher.
Pick the lowest, harshest tone you have rather than a bright beep, check the volume, and consider a vibrating pad if hearing is a factor.
- 3
If you wake groggy, try something melodic for two weeks.
It is cheap to test, and the early evidence leans that way. Judge it on how you feel 15 minutes after waking, not on the first morning.
- 4
If you switch it off in your sleep, change what stopping it takes.
Put the phone out of reach, or use an alarm that keeps ringing until you have done something that needs you awake.
Alarm sounds in Wakr
Wakr has 15 alarm tones, from melodic ones such as Soft piano, Marimba, and Gentle bells to plain beeps such as Retro beeper and Digital buzzer. Rising pulse gets louder across each loop. You can also use your own audio file. Whatever you choose, the sound does not stop until you finish a wake-up mission, such as walking 100 steps, so the tone only has to wake you, not keep you up. On iOS 26 and later, the alarm rings as a real system alarm through Apple’s AlarmKit.
To change the sound in the iPhone Clock app, edit the alarm and tap Sound. The iPhone alarm guide covers volume and snooze settings.
Quick answers
What is the best alarm sound to wake up to? To wake at all, a low-pitched, harsh tone has the strongest evidence. To feel less groggy, a melodic tone is worth trying, though the evidence is early.
What alarm sound wakes heavy sleepers? In fire-safety studies, a 520 Hz square-wave tone woke deep sleepers far more reliably than standard high-pitched beeps.
Is a gradual alarm better? In the one direct study, it improved mood but not sleepiness, and people did not get up any later.
Should I use a song as my alarm? If you like it and it wakes you, yes. The research looked at how melodic a sound is, not at particular songs.
This is a summary, not medical advice.
If you regularly sleep through loud alarms despite enough sleep, or you are worried about your hearing, talk to a qualified health professional. Wakr does not diagnose or treat sleep or hearing conditions.
Sources
- Alarm tones, music and their elements: Analysis of reported waking sounds to counteract sleep inertia, McFarlane, Garcia, Verhagen & Dyer, PLOS ONE, January 28, 2020.
- Auditory Countermeasures for Sleep Inertia: Exploring the Effect of Melody and Rhythm in an Ecological Context, McFarlane et al., Clocks & Sleep, May 29, 2020.
- Alarm Tones, Voice Warnings, and Musical Treatments: A Systematic Review of Auditory Countermeasures for Sleep Inertia in Abrupt and Casual Awakenings, McFarlane et al., Clocks & Sleep, October 20, 2020.
- Smoke Alarms for Sleeping Adults Who are Hard-of-Hearing: Comparison of Auditory, Visual, and Tactile Signals, Bruck & Thomas, Ear and Hearing, February 2009.
- Towards a better smoke alarm signal: an evidence based approach, Bruck & Thomas, Fire Safety Science, 2008.
- Do Sleeping Children Respond Better to a Smoke Alarm That Uses Their Mother’s Voice?, Smith, Chounthirath & Splaingard, Academic Pediatrics, April 2020.
- The SoundRise Alarm: The Impact of a Gradually Rising Alarm on Morning Mood and Waking-Up Behavior, Yang, Cera & Pauletto, Forum Acusticum, September 2026.
- Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood, Sundelin, Landry & Axelsson, Journal of Sleep Research, October 17, 2023.
