Most noises people make during sleep come from air vibrating soft tissue in the throat as it squeezes through a partially narrowed airway. That basic mechanism accounts for snoring, which is by far the most common sleep sound. But snoring is only one item on a surprisingly long list. Groaning, talking, screaming, grinding teeth, and even high-pitched whistling breaths can all emerge from a sleeping person, each with its own cause, its own sleep stage, and its own level of medical concern.
Snoring and the Physics of a Floppy Airway
When you fall asleep, the muscles that hold your upper airway open relax. If the airway narrows enough, the tissues around it start to flutter as air passes through, the same way a flag flaps in the wind. The soft palate is the main culprit for the harsh, rattling quality most people associate with snoring. Studies of snoring acoustics show that the pitch and character of the sound depend on which structure is vibrating: palatal snoring produces a lower, more tonal sound, while snoring originating from other parts of the pharynx scatters energy into higher-pitched, noisier frequencies.1PubMed. The acoustics of snoring
Plenty of factors determine whether your airway narrows in the first place. A thick soft palate, enlarged tonsils, a tongue that sits far back, a recessed jaw, or extra fat around the neck all reduce the space available for air.2PubMed Central. Implications of Obstructive Sleep-related Breathing Disorder in Dentistry: Focus on Snoring and Obstructive Sleep Apnea Sleep position matters too. Lying on your back lets gravity pull the tongue and soft palate backward, which is why some people snore loudly in supine sleep and barely at all on their side.3PubMed Central. Continuous and Loud Snoring Only in the Supine Posture
Occasional, quiet snoring with no breathing pauses and no daytime sleepiness is usually called primary snoring. It can be annoying, but on its own it is not considered dangerous. The trouble starts when the airway does not just narrow but collapses completely.
When Snoring Points to Obstructive Sleep Apnea
In obstructive sleep apnea, the airway seals shut repeatedly during the night. Each closure chokes off airflow until the brain rouses you just enough to reopen the passage, usually with a gasp or a loud snort. Most people with sleep apnea never fully wake during these episodes and have no memory of them.
Acoustic research reveals something interesting about these events. When the airway reopens after a complete collapse, the sudden rush of air through a still-narrow gap produces snoring sounds at extremely high frequencies, including ranges above what humans can hear. The frequency content of the snoring sound correlates strongly with how many obstruction events a person has per hour of sleep, meaning the character of your snoring actually carries information about severity that a clinician can measure.4Elsevier. Characterisation of upper airway obstructions using wide-band snoring sounds
If a bed partner notices that your snoring is punctuated by silences followed by choking or gasping, or if you wake up feeling exhausted despite sleeping a full night, those are classic red flags for obstructive sleep apnea and worth bringing up with a doctor. Untreated, the repeated oxygen dips and sleep fragmentation raise risks for cardiovascular disease, metabolic problems, and daytime impairment.
Catathrenia, the Mysterious Sleep Groan
Catathrenia sounds nothing like snoring. It is a drawn-out groaning or moaning noise that happens during exhalation, often with a pitch and tone that can sound unsettlingly human and intentional. Bed partners sometimes describe it as a prolonged “eee” or “mmm.” Unlike snoring, which involves passive tissue vibration, catathrenia involves the vocal cords actively coming together and vibrating during a long breath out.5PubMed Central. Catathrenia (Nocturnal Groaning): A Social Media Survey and State-of-the-Art Review
Acoustic analysis of these groaning episodes finds they have clear harmonic structure and a measurable fundamental frequency, averaging around 195 Hz, roughly the pitch of a low singing note. Episodes last about 11 seconds on average but can stretch well past a minute. Some people produce thousands of groaning events in a single night. In one detailed study, researchers documented over 3,700 groaning episodes across 23 patients.6Physiological Measurement. Polysomnographic characteristics and acoustic analysis of catathrenia (nocturnal groaning)
Catathrenia happens most densely during REM sleep, the dream-heavy stage. About 70% of patients in that same study showed a REM-predominant pattern, even though individual groaning events could turn up in any sleep stage.6Physiological Measurement. Polysomnographic characteristics and acoustic analysis of catathrenia (nocturnal groaning) Research into the brain activity behind it suggests that most groaning clusters are preceded by a brief cortical arousal, a mini-awakening the person does not remember.7PubMed Central. Catathrenia as a REM predominant disorder of arousal
Catathrenia is not associated with breathing obstruction or oxygen drops, which makes it medically benign in most cases. Its main problem is social: the noise can be loud, sometimes reaching about 66 decibels, which is roughly conversational volume, and it can seriously disturb a partner’s sleep. Treatment is limited; CPAP machines, the standard device for sleep apnea, have been tried with mixed results, and no medication reliably eliminates the groaning.
Sleep Talking
Sleep talking, or somniloquy, ranges from mumbled gibberish to full, grammatically correct sentences. Research on the content of sleep speech shows that it mirrors waking language in surprising ways, preserving normal syntax, meaning, and even conversational turn-taking, as if the sleeping brain were holding up its end of a dialogue.8Sleep. What Does the Sleeping Brain Say? Syntax and Semantics of Sleep Talking in Healthy Subjects and in Parasomnia Patients
Electroencephalography studies have looked at what happens in the brain just before a person starts talking in their sleep versus making a wordless vocalization like a moan or grunt. Verbal sleep talking is preceded by a distinctive drop in certain brainwave frequencies, particularly over the left parietal region, an area involved in language processing. This pattern does not appear before nonverbal sounds, suggesting the brain is selectively “switching on” language circuits while the rest of the person stays asleep.9Sleep. Sleep talking versus sleep moaning: electrophysiological patterns preceding linguistic vocalizations during sleep
Sleep talking is extremely common in children and generally harmless. In adults, frequent sleep talking sometimes clusters with stress, sleep deprivation, or fever, but it rarely signals a serious disorder on its own. The main exception is when talking accompanies violent movements during dreams, which points toward a different condition entirely.
REM Sleep Behavior Disorder
During normal REM sleep, the brain essentially paralyzes the body’s voluntary muscles so that you do not physically act out your dreams. In REM sleep behavior disorder, that paralysis fails. People with this condition may shout, swear, kick, punch, or leap out of bed while dreaming, often with no awareness of what they are doing. The vocalizations can be intense: yelling, screaming, or carrying on one side of a heated argument.10PubMed. The REM sleep circuit and how its impairment leads to REM sleep behavior disorder
This is one sleep noise that genuinely warrants medical attention, for two reasons. First, the physical acting-out can injure the person or their bed partner. Second, in people over 50, isolated REM sleep behavior disorder is now recognized as one of the strongest early markers for neurodegenerative diseases like Parkinson’s disease and a related condition called dementia with Lewy bodies. Not everyone who develops it will go on to develop neurodegeneration, but the association is strong enough that specialists track these patients closely over time. Diagnosis requires a sleep study that confirms the loss of normal muscle paralysis during REM sleep.11Sleep. The Clinical Phenotype of Idiopathic Rapid Eye Movement Sleep Behavior Disorder at Presentation: A Study in 203 Consecutive Patients
Sleep Terrors and Screaming in Deep Sleep
Sleep terrors are entirely different from nightmares, even though both can make a person scream. Nightmares happen in REM sleep, and the person usually wakes up remembering a vivid, frightening dream. Sleep terrors erupt out of deep non-REM sleep, usually within the first three hours of the night. The person bolts upright, screams, looks terrified, and may thrash around, but they are not truly awake and usually have no memory of the event afterward.12PubMed Central. Sleep Terrors: An Updated Review
The physical signs are dramatic: racing heart, rapid breathing, sweating, flushed skin, dilated pupils. Trying to comfort or restrain the person during an episode tends to make things worse. Sleep terrors are far more common in children and most kids grow out of them without treatment. In adults, persistent sleep terrors are less common and can be linked to sleep deprivation, stress, fever, or certain medications that deepen non-REM sleep.
Teeth Grinding
Sleep bruxism produces a grinding, clenching, or rhythmic crunching noise that comes from the jaw muscles contracting involuntarily. The characteristic pattern involves rhythmic or sustained contractions of the masseter and temporalis muscles, the main chewing muscles on either side of your head.13British Dental Journal. Sleep bruxism: an overview for clinicians
At low frequency and force, these jaw movements are considered a normal part of sleep and do not necessarily cause problems. They become pathological when they increase in frequency and intensity and start producing symptoms: worn-down teeth, jaw pain, headaches, or damage to dental work.14Sleep Medicine Clinics. Sleep Bruxism A dentist spotting unusual tooth wear is often the first person to flag the issue. Night guards can protect the teeth but do not stop the underlying muscle activity. Stress reduction and treating any coexisting sleep apnea sometimes reduce the severity.
Nocturnal Stridor
Stridor is a high-pitched, strained sound caused by air forcing its way through a narrowed larynx. Unlike snoring, which originates in the floppy tissues of the throat, stridor comes from the vocal cord area itself. In adults, sleep-related stridor can be a warning sign of a neurological condition called multiple system atrophy, in which the vocal cords involuntarily draw together during sleep, narrowing the airway.15PubMed. Sleep-related stridor due to dystonic vocal cord motion and neurogenic tachypnea/tachycardia in multiple system atrophy A consensus statement defines it as a harsh, primarily inspiratory sound caused by laryngeal dysfunction during sleep.16PubMed. Stridor in multiple system atrophy: Consensus statement on diagnosis, prognosis, and treatment
In infants, the picture is different. The most common cause of stridor in babies is laryngomalacia, a condition where the tissue above the vocal cords is floppy and collapses inward with each breath. It usually resolves as the child grows, though it can sometimes overlap with obstructive sleep apnea.17PubMed. Prevalence and natural history of obstructive sleep apnea in pediatric patients with laryngomalacia Any new stridor in an adult, especially one that only appears during sleep, should be evaluated by a physician, because the neurological conditions behind it benefit from early identification.
Allergies, Congestion, and Mouth Breathing
You do not need a structural abnormality to make noise during sleep. Sometimes the culprit is temporary: a stuffy nose from a cold, seasonal allergies, or chronic rhinitis. Allergic rhinitis increases the risk of sleep-disordered breathing through two routes: it raises resistance to airflow in the nose, and the resulting switch to mouth breathing shifts the jaw downward, narrowing the space behind the tongue.18PubMed. The linkage of allergic rhinitis and obstructive sleep apnea
The shift to oronasal breathing when the nose is blocked is thought to be a common pathway toward sleep-disordered breathing, regardless of the original cause of the congestion.19Chest. The Nose and Sleep-Disordered Breathing: What We Know and What We Not Know In children, this effect is especially pronounced. A study comparing children with and without allergic rhinitis found that those with allergies were about three times as likely to snore and nearly three times as likely to breathe through their mouths during sleep. They also showed higher rates of sleep talking and restless sleep.20PubMed. Effect of allergic rhinitis on sleep in children and the risk factors of an indoor environment
If your sleep noises are worse in allergy season or when you have a cold, the cause is likely transient. Treating the nasal congestion with saline rinses, nasal corticosteroid sprays, or antihistamines can often quiet things down. In children with chronic nasal obstruction, long-term mouth breathing can actually reshape facial growth in ways that predispose them to airway problems later, so addressing the congestion early has lasting benefits.21PubMed Central. Craniofacial anatomical determinants of pediatric sleep-disordered breathing: A comprehensive review
Alcohol, Reflux, and Other Nighttime Triggers
Alcohol is one of the most reliable ways to make sleep noises worse. It relaxes the muscles of the upper airway in a dose-dependent manner, meaning the more you drink, the floppier the airway becomes.22PubMed. Upper airway closing pressures in snorers People who do not normally snore may start after a few drinks, and those who already snore tend to snore louder and with more obstruction. Sedative medications, including some sleep aids and muscle relaxants, work through a similar mechanism.
Gastroesophageal reflux is a less obvious contributor to nighttime sounds. When stomach acid reaches the upper airway during sleep, it can trigger coughing, throat clearing, and a sensation of choking. Two mechanisms are at play: acid can make direct contact with the larynx (sometimes through micro-aspiration), and acidification of the lower esophagus can trigger reflex responses through the vagus nerve that affect the throat and lungs.23PubMed. Review article: supra-oesophageal manifestations of gastro-oesophageal reflux disease and the role of night-time gastro-oesophageal reflux If you regularly wake with a sore throat, hoarseness, or a chronic cough and your sleep partner hears you clearing your throat or coughing through the night, reflux is worth considering, especially since it worsens in the lying-down position.
What Your Bed Partner Goes Through
Sleep noises rarely bother the person producing them, but the person sleeping next to them is another story. Research on the bed partners of people with obstructive sleep apnea has documented measurably lower sleep quality, more time spent in light sleep, and higher rates of pain and emotional distress compared to partners of non-snoring controls.24PubMed. Disturbed sleep and musculoskeletal pain in the bed partner of patients with obstructive sleep apnea These partners spent more time awake during the night and showed more alpha brainwave intrusion during deep sleep, a pattern associated with non-restorative rest. The effects were not just subjective complaints: they correlated with measured changes in pain sensitivity and fatigue.
This means that the motivation to address sleep noises is often as much about the other person in the bed as about the sleeper. Many couples arrive at a sleep clinic because the partner pushed for it, not because the snorer noticed a problem. And sometimes the right first step is simply recording the sounds at home. Smartphone apps and recording devices can capture what happens during the night in a way that helps both the person and their doctor understand the pattern, whether it sounds like rhythmic snoring, sudden gasps, long groans, or something else entirely.
Treating the Noise
Treatment depends entirely on which noise you are making and what is behind it. For straightforward snoring, the first-line conservative approaches are positional therapy (training yourself to stay off your back) and weight loss if excess weight is a factor.25PubMed Central. The Diagnosis and Treatment of Snoring in Adults Mandibular advancement splints, which are custom dental devices that hold the lower jaw slightly forward to widen the airway, can meaningfully reduce snoring. In comparative studies, these oral appliances reduced the frequency of breathing disturbances by about 42%, while CPAP reduced them by about 75% and a common surgical procedure called UPPP reduced them by about 30%.26PubMed Central. Review of oral appliances for treatment of sleep-disordered breathing CPAP remains the gold standard for obstructive sleep apnea, but oral appliances serve an important role for people who cannot tolerate the mask.
For teeth grinding, a night guard protects against dental damage while behavioral strategies like stress reduction and sleep hygiene address contributing factors. REM sleep behavior disorder is typically managed with medications under close neurological follow-up. Sleep terrors in children usually resolve on their own; in adults, improving sleep consistency and reducing known triggers helps. Catathrenia remains one of the more frustrating conditions to treat, with no reliable solution beyond reassurance that it is not harming the groaner’s health.
How Children Differ
Children make a wider range of sleep noises than adults, partly because their airways are structurally different and partly because parasomnias like sleep terrors and sleep talking are more common in younger brains that are still maturing. The most common cause of significant snoring in children is enlarged adenoids and tonsils, not the tissue laxity and weight-related narrowing that drives most adult snoring.21PubMed Central. Craniofacial anatomical determinants of pediatric sleep-disordered breathing: A comprehensive review Adenotonsillectomy is the standard first-line treatment for pediatric obstructive sleep apnea, though some children have residual breathing issues afterward if craniofacial factors are also at play.
Parents sometimes worry about every sound a baby or toddler makes at night. Grunting in newborns is common and usually related to immature breathing patterns or digestive activity. Stridor in an infant, as noted earlier, most often comes from laryngomalacia and tends to improve with growth. The sounds that warrant a pediatrician’s attention are loud, habitual snoring (most nights, not just during a cold), pauses in breathing, and any high-pitched inspiratory noise that persists beyond the first year of life.
When a Sleep Study Is Worth Pursuing
Not every sleep noise needs a formal evaluation, but certain patterns should lower your threshold for seeking one. Witnessed apneas, where a bed partner sees you stop breathing, are the clearest signal. Excessive daytime sleepiness that persists despite seemingly adequate sleep time is another. Morning headaches, waking with a dry mouth or sore throat every day, and unexplained difficulty concentrating can all point toward fragmented sleep you are not aware of.
For less common sounds like groaning or stridor, a polysomnography study (an overnight recording in a sleep lab) is often the only way to pin down what is happening. The study tracks brainwaves, muscle activity, airflow, breathing effort, and oxygen levels simultaneously, which lets clinicians distinguish between conditions that sound similar but have very different implications. A person who shouts during REM sleep and a person who screams during deep non-REM sleep may sound identical to a bed partner, but the underlying disorders, their prognoses, and their treatments have almost nothing in common. The recording makes the difference.