The best — and worst — iPhone alarm sounds to wake up to

Certain tones and frequencies can cause sleep inertia, or the groggy feeling that can follow you all morning.

Turns out your relationship to your morning alarm doesn’t have to be so fraught — certain tunes and frequencies can even help start the day on an easier note.

A new analysis from audiovisual agency Startle reveals the best and worst options for a smooth transition into waking.

After sampling 140 smartphone alarms, the researchers found that over half of the iPhone’s default options could be wreaking havoc on your nervous system, making it harder to get out of bed in the morning.

Certain high-pitched, abrupt alarm tones can send the body into a state of fight or flight. Jo Panuwat D – stock.adobe.com

That groggy feeling actually has a name, according to psychologist and Panda London sleep expert Ritz Birah. It’s called sleep inertia.

And it can last anywhere from a few minutes to more than an hour, depending on factors like how sleep-deprived you are, where in your sleep cycle you were when you were jolted awake and how you were woken up, including the sound of your alarm.

Biologically speaking, those aggressive, frantic, high-pitched alarm tones can literally launch the body into a state of fight or flight — the last thing you want upon waking.

“Sudden alarms can trigger a short stress response,” Birah told The Post. “Loud, jarring sounds activate the sympathetic nervous system, leading to a spike in heart rate, blood pressure and cortisol. While this reaction is brief, starting the day in that stressed state can leave people feeling groggy, irritable and mentally foggy.”

If those abrupt awakenings become a habit, the sleep inertia can get worse over time, “making it harder for the brain to fully transition into alertness.”

Conversely, a good alarm won’t try to shock you awake. Instead, it will have a melodic, rhythmic cadence that “works with the brain’s natural waking process” by gradually increasing the volume.