Hearing a mysterious humming or droning noise at night can be alarming and confusing. While there are several possible explanations for these auditory experiences, the most common causes are tinnitus, electrical devices, neighbors, and animals/insects.
Tinnitus
Tinnitus is the medical term for hearing noises that come from inside your body, rather than from an outside source. It’s commonly described as a ringing, buzzing, roaring, clicking, or hissing sound that only you can hear. Tinnitus affects roughly 10-15% of adults and is often noticed most at night when your surroundings are quiet.
The specific cause of tinnitus is not always known, but it can stem from age-related hearing loss, earwax buildup, inner ear damage, migraine headaches, TMJ disorders, blood vessel disorders, medication side effects, and other health conditions. If you only hear the noise at night, it may simply be easier to detect when your environment is quieter.
Tinnitus often worsens with age, so adults 40 years or older are more likely to experience it. The sound in both ears or inside your head is a key indicator that tinnitus may be the source of nighttime humming or buzzing noises.
Electrical devices
Many electrical devices and appliances emit low hums or buzzes that are hard to notice during the day but become audible at night when your home is still. Items like refrigerators, computers, TVs, chargers, heaters, and air conditioners all contain motors, transformers, and coils that can produce constant background noises.
Fluorescent light bulbs also buzz slightly from the vibration of gas ions inside the tube. You may only hear appliance and light bulb sounds at night when household activities calm down. Turning off major devices or listening closely near each one can help pinpoint the electrical culprit.
Common electrical culprits:
- Refrigerators
- Furnaces and air conditioners
- Computers and servers
- Televisions and monitors
- Chargers and transformers
- Fluorescent lights
Neighbors
In apartments, condos, dorms and other shared living spaces, nighttime noises from neighbors can be audible through walls, ceilings, vents and pipes. Conversations, music, televisions, snoring, and fans can all produce muffled humming or droning sounds in your own home at night when most people have quieted down.
Certain types of equipment like ventilation systems, generators, and pool pumps can also generate humming noises that carry between units. Determining if a neighbor is the source usually requires process of elimination by listening in several rooms and also outside your own home.
Animals and insects
The sounds of animal and insect activity can sometimes translate to a steady humming noise, especially when amplified by pipes or vents. Causes include:
- Bee hives and wasp nests – Bees produce a low pitched drone from the rapid flapping of their wings. This gets louder when amplified by a structure.
- Cicadas – Males create a persistent humming or buzzing during summer mating calls.
- Rodents – Gnawing and scurrying noises can be perceived as humming.
- Pigeons or bats – Rustling and cooing sounds in chimneys and attics can resemble humming.
- Cat purring – The deep rhythmic thrumming of a cat purr can be audible and soothing at night.
Figuring out if an animal or insect is causing the humming involves listening for higher-pitched intermittent noises in sync with the hum. Locating access points like chimneys, vents and holes in the structure can help pinpoint the access point.
Other causes
Less common causes for hearing a humming noise at night include:
- Hallucinations or auditory processing disorders
- Earwax buildup
- A brain tumor pressing on auditory nerves
- Side effects of certain medications
Humming noises solely inside your head with no audible sound clues may indicate a neurological or mental health condition. Consult a doctor if the humming persists with no other apparent cause.
What’s normal and what’s not?
Hearing a very soft and constant humming sound at night is usually nothing to worry about. Causes like electrical appliances, tinnitus, and ambient noise from neighbors are perfectly normal and harmless.
However, take note if the humming sound is:
- Loud, buzzing, or distorted
- High-pitched and sporadic
- Only audible in one ear or one part of your home
- Keeps you from falling asleep
- Causes headaches or disorientation
Unusual humming noises, especially those only you can hear, may indicate an underlying medical condition and warrant further evaluation by an audiologist or other doctor.
| Common Causes | Key Clues |
|---|---|
| Tinnitus | Humming in both ears or inside your head |
| Electrical devices | Buzzing or humming stops when unplugged |
| Neighbors | Noises are louder through walls or vents |
| Insects/animals | Intermittent buzzing, chirping, or scratching |
Conclusion
Hearing a mysterious droning or humming noise at night can have many explanations, most of which are harmless. Start by determining if others can also hear the sound. Check electrical devices, listen near walls and vents, and scan for insect activity during the daytime. But also monitor your symptoms and talk to a doctor if the humming persists and affects your well-being.
