A Flutter Fifty Times a Second
That rumble from across the room is a small physics problem. Scientists have modeled the upper airway as a tube with a soft, collapsible section. When that section narrows, it closes and reopens over and over as air rushes past, about 50 times every second. The airflow turns unstable and turbulent, and that rapid flapping makes the noise.
The main culprit is the soft palate, the soft back part of the roof of your mouth. In one study it vibrated in 100% of snoring cases. The throat walls, the epiglottis and the base of the tongue joined in less often. Snoring mostly happens while breathing in, and it tends to be louder in deep sleep and in REM sleep.
People have been describing snoring since at least the fifteenth century. And the familiar "Zzz" we use to show it may have come from comics.
Blame Your Nose, Your Tongue and Gravity
The nose plays a bigger role than you might guess. It causes over 50% of the total resistance to airflow in the airway. Its narrowest point, the internal nasal valve, sits only about 1.5 cm inside the nostril. Because of how air moves through tubes, even a tiny narrowing there makes a big change in airflow. A stuffy nose from allergies can be enough to tip the balance.
Gravity is the other troublemaker. When you sleep on your back, it pulls your tongue backwards, where it can block the airway. On top of that, the throat muscles relax during sleep.
Body shape matters too. A collar size of more than 42 cm (17 in) means more fat around the throat. In children, the most common cause is enlarged tonsils and adenoids, since tonsils are larger at younger ages. And some people simply inherit a tendency to snore.
Every Snore Has Its Own Pitch
Not all snores sound alike, and the sound gives clues about where it comes from. Snoring from a fluttering soft palate has an average peak frequency of 137 hertz, a low hum. Snoring from the base of the tongue is far higher, at 1243 Hz. Snoring from the epiglottis sits around 490 Hz. That is why an audio recording of a night of snoring can help a doctor.
Volume is measured too. Mild snoring is 40 to 50 decibels, about like quiet conversation. Moderate snoring, 50 to 60 decibels, is like a car driving slowly past. Severe snoring goes above 60 decibels, as loud as busy traffic or a vacuum cleaner. On average, men snore more loudly than women.
To be sure, doctors may order an overnight sleep study called polysomnography, the gold standard for checking sleep disorders. It helps rule out obstructive sleep apnea, where snoring comes with pauses in breathing, gasping or choking.
The Person Next to You Pays the Price
Snoring is sometimes more of a problem for the person sleeping nearby than for the snorer. Snorers are often unaware of their own noise. And because snoring can be irregular, changing in volume and character, it is hard to get used to. It can wake the listener and stop them from falling asleep again. Many try a gentle nudge, which can make the snorer change position and quiet down.
The numbers are striking. In one study, treating men's snoring gave their partners 13% better sleep efficiency and an average of one hour of extra sleep. One hour lost per day adds up to a whole night lost every week. One small study even found partners had measurable hearing loss in the ear that usually faced the snorer, though overall evidence for this is thin.
Snorers feel it too. Snoring has been linked to daytime sleepiness, headaches on waking and trouble focusing. In children, it may affect mood, attention and school performance.
Balloons, Pillows and Boil-and-Bite
The first fixes are often simple. Sleeping on your side stops the tongue from falling back. Losing even 4.5 kg (10 lbs) can improve snoring, and stopping smoking helps too. Special pillows that keep the jaw slightly forward have been shown to reduce how loud snoring is. But be careful: many over-the-counter gadgets, like stop-snoring rings and wrist bands, have no scientific evidence behind them.
There are also workouts for your mouth and throat, called myofunctional therapy. They include saying vowel sounds, moving your tongue in different directions, sucking through a narrow straw and blowing up balloons. One review found it cut snoring intensity by 51%, though other studies found little effect.
Dental devices are another option. Some are "boil and bite": you soften them in boiling water, then bite down with your jaw pushed forward. For sleep apnea, the gold standard is CPAP, a machine that pumps air through a mask to keep the airway open.
