Photograph of  grass growing indoors in this unusual homeBuilding Noise Problems
Diagnose, & Cure Noise Problems in Building Interiors

  • NOISE / SOUND DIAGNOSIS & CURE - home CONTENTS: Building & house noises, a complete catalog of sources of building noises: lists of causes, cures, and detection methods for indoor noise pollution.
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Building noise troubleshooting: causes & cures.

Here we provide an extensive catalog of the sources of annoying sounds or noise complaints at or around buildings.

These articles discuss building noise control: how to inspect, diagnose & cure noise or sound problems in homes or commercial buildings. Information is provided about auditory (hearing), visual, historic, medical, or other clues of building condition that explain various sounds heard in buildings. We also discuss methods of sound or noise control in buildings during construction or as a building retrofit.

Green links show where you are. © Copyright 2015, All Rights Reserved.

How to Identify & Cure Noises & Sounds in Building Interiors

Table of typical sound levels in decibels dB (C) J Wiley & Sons Best Practices Steven Bliss

[Click to enlarge any image]

Some building noises are just an annoyance - we'll focus on sound control, sound isolation, and sound insulation methods. But other building sounds or noises may be a sign of trouble, failing equipment, insect attack, rodent infestation, or other more dangerous conditions.

Our page top photo showed a severe air bypass leak at an attic pull-down stair. Occupants could at times hear air rushing through this opening.

This article explains how to locate the source of, identify and correct various building sounds and noises indoors or on occasion, noises from outside that penetrate indoors at annoying levels.

While we touch on environmental noise coming from outside of buildings (aircraft noise, highway noise, noisy neighbors) the focus of this article series is on identifying and curing unwanted indoor noise sources in buildings - noise control.

How are Noises Transmitted in Buildings?

Regardless of their source, noises are transmitted in buildings by two methods.

Airborne Sound: Sound waves traveling through air move between building areas - such as through open windows, doors, or stairwells.

Mechanically transmitted sound: When sounds move through solid building components such as floors, ceilings, walls, framing, carrying sound from one area to another the sound transmission is referred to more technically as impact insulation class transmission or IIC sound transmission.

In many cases the source of an annoying building sound may be obvious and we can move immediately to strategies for reducing that source to an acceptable noise level. But we also receive queries from people who have difficulty tracing a sound to its source, or who are unsure if a sound that they hear at a known source (say a humming sound at an electrical component) is normal or means trouble.

In our collection of sources of building sounds and noises, below, we describe common noises that may come from various sources and we link to more detailed diagnostic and repair advice for these problems.

Separately at SOUND CONTROL in buildings we provide a series of detailed articles on noise or sound transmission control - that is, methods for reducing unwanted building noise levels through building design, insulation, sound isolation, and noise barriers.

Find the Source of Building Noises by Keeping a Sound or Noise Event Log

To track a mystery-noise or sound to its source in a building, try keeping a noise log, noting the conditions, times, events, and information we list in our printable SOUND EVENT LOG.

We provide a sound event log in three formats:

Alphabetical List of Building Noises by Sound Source or Sound Type

Beginning below, we provide an alphabetically-ordered catalog of building noises and sounds, with suggestions for tracking down these disturbances.

Air Conditioning or Heat Pump System Noises

  • At AIR CONDITIONING & HEAT PUMP NOISES we discuss a range of noises can be traced to air conditioning systems, including sounds of air leaks into or out of air ducts and air handlers as well as mechanical sounds traced to the air handler or blower, or the compressor unit (outside).
    • Air handler / blower indoor cooling unit noises:
      see AIR HANDLER / BLOWER NOISES for a discussion of air leaks, bubbling, clicking, duct noises, fan noises and vibration dampener noises, howling or hissing in air handlers and ducts, rattling at fan motors, hissing at failing electrical components, and more including the articles on these problems listed just below.
    • Air leaks in ductwork often make a roaring or hissing sound. See
    • COMPRESSOR CONDENSER NOISES provides detailed diagnostic help in finding, evaluating, and fixing noisy compressor units. Humming, rattling, explosion noises, bangs, clanks, hissing noises.
    • DUCT SYSTEM NOISES, including air leaks, hisses, dripping condensation, creaks and clicks from thermal expansion & contraction, rattling & buzzing from loose components
    • ELECTRIC MOTOR NOISE DIAGNOSIS - humming sounds from hard-starting motors
    • FAN NOISES, HVAC - humming, rattling, banging, clicking noises traced to fan motors, fan belts, or fan blades impacting other items due to loose fans or failed fan bearings.
    • HOWLING HVAC sounds from air conditioners, air handlers, blower fans, heat pumps, furnaces, duct systems & their motors
    • Other building HVAC system noise sources:

      See NOISE CONTROL for HEATING SYSTEMS where we describe other heating system noise sources and cures.
  • Bubbling sounds occur in all types of building piping systems when there is air or gas mixed in with water or another liquid such as refrigerant. Bubbling sounds in hot water heating systems is discussed at

      while bubbling sounds in the refrigerant piping is discussed at
    • REFRIGERANT LEAK REPAIR and may indicate a refrigerant leak, though bubbling sounds on split systems at the indoor wall unit may be normal for some products - see our note below about water noises.

      You may also hear bubbling sounds in water piping if there is excess air in the water supply system. See
  • Buzzing, snapping, crackling, popping - may be dangerous electrical switch or breaker indicators. Buzzing also occurs at failing or failed relays such as the relay in a heating system aquastat or circulator controller or in relays used to control HVAC fans, blowers, and compressor motors.
  • Clicking noises from relays & controls can be heard at either the compressor/condenser or at the indoor air handler unit: A failing or defective thermostat or to a defective control itself can cause relays to click on and off repeatedly. - thanks to reader Michael Anderson.

    A clicking noise might be traced to a failing electrical control in the air handler or outside at the fan-compressor unit, leading to a control switching on and off too rapidly.
  • Duct system noises: hisses, whistles, even roars, and occasionally clunk or clank sounds from expanding or contracting metal ductwork. Take a look at
    • LEAKY DUCT CONNECTIONS. Leaks around the return air register are common and sometimes noisy - see
    • RETURN DUCT AIR LEAKS. Hisses and whistles in supply air ducts and registers might be present too - see
    • SUPPLY DUCT AIR LEAKS. Also buzzing, rattling, clanking or other noises originating at the air handler/blower unit may be transmitted into the physical ductwork and thus the building, if the system lacks an adequate vibration dampener
  • Fan noises on heating and air conditioning systems are discussed

    at FAN, COMPRESSOR / CONDENSER UNIT and may include rattling and clanging
  • Heating pipe or radiator noises -
  • Humming sound might be traced to a failing compressor motor or a failing electric motor on a blower fan.

    At HUMMING NOISES we list common sources of hum sounds found in or around buildings.
  • Sizzling noises from a split system air conditioner / heat pump may be heard at the wall mounted unit when the system is in heating mode. [10]
  • Squeaking noises from a split system air conditioner / heat pump might be heard coming from the wall mounted unit. According to Fujitsu, This is the result of minute expansion and contraction of the front cover due to temperature changes. [10]
  • Water pipe noises - banging water pipes, see WATER HAMMER NOISE DIAGNOSE & CURE
  • Water pump noises - see
  • Water tank noises - see WATER TANK NOISE FAQs
  • Water noises, a sound like running water may be heard in the refrigerant or condensate piping of a split system air conditioner or heat pump while the equipment is running and/or briefly during unit start-up as well as for a period immediately after the unit shuts off.

    While usually we consider the sight or sound of bubbles in the refrigerant piping as an indication of low refrigerant, for some systems this may not be the case and for at least some split system models Fujitsu points out that this sound may be normal. [10] However if you hear bubbling in the refrigerant piping and the system is not cooling properly, indeed there may be an improper charge or refrigerant may be leaking. See Running or bubbling water sounds are heard in hot water heating system pipes, baseboards, radiators, & fan convectors if there is excess air in the heating system piping.

Air Leaks: How to Track Down Air Bypass Leak or Air Leak Noises in buildings

This topic has been moved to a new article found

Isn't that raccoon cute?

Watch out for bites, rabies, and for racoons who like to find a way into the attic where they bat around the Christmas tree ornaments and leave little sooty footprints all over everything.

Animal noise and animal-caused noises in buildings, diagnosis & cure

Raccoon outdoors on a downspout (C) Daniel Friedman

This article topic has been moved to a new article found

Appliance Noises in buildings, Sources of

This article topic has been moved to a new article found

Appliance noises in buildings are a bit easier to track down. If you are uncertain just which appliance is a noise source, or if it is a noise source, just try turning off individual appliances to check for cessation of noise. Appliance noises cover a wide range, from humming refrigerator compressors to rattling loose metal parts.

Chimney noises in or on buildings - Danger Signs?

Chimney damage (C) Daniel Friedman

This article topic has been moved to a new article found

Watch out: A chimney fire sounds like a roaring freight train.

If you suspect a chimney fire and can do so safely, shut down your wood stove (close all air intakes) or close any chimney dampers as well, immediately exit the building, and call the fire department from outdoors.

Dripping Water Sounds in buildings, How to Track Down

This noise diagnosis and repair topic is now found

Electrical Equipment or Electrical System Noises in buildings: diagnosis & cure

Please see details we have moved

Watch out: Electrical System Noises can be signs of dangerous conditions: buzzing circuit breakers or fixtures may indicate that an electrical circuit is short circuiting or that a circuit breaker is not tripping when it should.

Fans and Fan Noises in buildings & How to Control Fan Noises

This topic has moved


Flooring and Floor Noises in buildings

Antique wood floor (C) Daniel Friedman

This information was moved to FLOORING NOISES in BUILDINGS

Also see FLOOR TYPES & DEFECTS - inspection, diagnosis, repair, and installation tips for resilient flooring, vinyl and asphalt floor tiles, wood flooring, tile floors, carpeting in buildings.

Ghost Noises or Odors in & Around Buildings

Among of our building inspection & diagnosis clients have been a few folks who were quite sure that noises and even some visions in buildings were due to the presence of spirits or ghosts.

In most cases sounds and odors were tracked to a physical source and speaking more accurately, if a physiological, psychological, or neurological cause of noise perception is ruled out, all other building noises can ultimately be tracked to a physical source inside or outside of the building.

Readers with suggestions about diagnosing

unresolved odors

or unexplained noises in buildings


are invited to comment using the comment box found at the bottom of each InspectApedia article.

Hardware Noises in Buildings: hinges, locks, bolts, etc. can be sources of surprising building noises

Toilet paper holder squeaking (C) Daniel Friedman

We have traced creaking, chirping, and creaking noises to moving hardware, typically metal or wood or metal and wood parts moving across one another.

More often we find these building noise sources by tracking the sound to a point of origin, seeing something moving, and then relating the sound to the cause of movement. A squeak or creak may be traced to use of a particular building door such as a room passage door or a cabinet door.

Often a squeak or creak that seems to occur in regular intervals that diminish in volume is traced to a hinged fixture that moves when disturbed. Some examples include:

  • A creaking squeaking noise traced to a metal toilet paper holder that squeaked when it was jostled to move from side to side (photo, above left). Ironically this creaky toiler paper was a cast brass bird that was squeaking in a sound not unlike a chirping bird.
  • A shrieking noise traced to a metal hinge supporting a building sign that waved when wind was blowing
  • A creaking towel dispenser

Health, Neurological, and Psychologically-Related Noise Complaints in buildings

Sleep Mate white noise generator (C) Daniel Friedman

An introduction to this topic is now found

Details about this topic are found
at HEALTH RELATED NOISE COMPLAINTS. Health related noise and apparent noise sources can involve common aging or hearing disorders, dementia, or other serious medical conditions.

Hearing Disabilities and Building Noises

Hearing Disabilities and the ability to identify and track the source of noises in buildings can be difficult for the hearing impaired.

Details are

Heating System Noises & Building Temperature-Change Noises

A quick summary of common sources of heating noise problems is

Or see our detailed heating noise diagnosis and repair article series on heating system noises found

Hissing Noises in buildings

This data was moved

Humming Sounds at buildings


Howling Deck Noises: check wind, structure, surface textures

A summary of common sources of howling noises in buildings with links to howling noise diagnostic articles

(Nov 2, 2014) Carolyn said:

We just had our deck rebuilt, changing the warped wood for grooved composite boards held together by hidden Trex fasteners. The new deck makes a howling sound when the wind blows. We ruled out the deck balusters and railing, so we know it is something to do with the decking. Our builder is as stumped as are we. Any ideas on how to get to the root of the problem and fix it?


Carolyn, if I could send you a prize for "best question" I'd do so.

Before posing a solution lets gain confidence in the noise cause.
I suspect the howling deck is a feature of one of the following, combined of course, with wind direction and site or terrain shape and features.

. Size / spacing of decking boards or gaps
. Framing orientation vs wind direction
. Wind over textured surface
. Wind through guardrails or balusters
. Wind redirection caused by decking,
. Something else we've not thought of

You could try a directional mike, even a mechanic's stethoscope but let's try something else first.

Try stapling house wrap first underneath the entire deck floor, from below, on the bottom of the joists. Don't worry, it won't be permanent.

For a complete discussion of howling noises traced to building decks including a completion of discussion of Carolyn's question above,
see HOWLING DECK NOISE- surface textures of decking, possibly framing, deck gaps, wind direction, other factors

Insect Noise and Insect-caused Noises in buildings: buzz, chirp, hum

Carpenter Bee closeup photo (C) Daniel Friedman

Insect noise and insect-caused noises in buildings include the following

  • Buzzing - bees in walls such as honeybees nesting in a building wall or roof cavity, or other bee activity on the building exterior - such as carpenter bees. Buzzing noises may be a colony of honeybees in the building wall.
    Watch out: don't go cutting the wall open - you may be attacked.
  • Chirping - cricket infestations
  • Termites or carpenter ants, while tiny as individuals, as a group, chewing away at wood components in a building can make a chewing or tearing noise that some people and many pets or other animals can hear, especially if there is no covering background noise.
  • See WOOD DESTROYING INSECTS carpenter ants, powder post beetles, & other wood destroying organisms

Plumbing System Noises in buildings

Our article PLUMBING SYSTEM NOISE SOURCES lists the sources of all types of plumbing noises and traces them to their source.

For the broad topic of controlling plumbing noises in buildings

Roof Noise Transmission & Structural Noises in buildings: Sources, Causes, Remedies

Details about roof noise and sound transmission cause and remedy are
ROOF NOISE TRANSMISSION. Excerpts are below.

Metal roof, Key West FL (C) Daniel Friedman

Certain building configurations, such as occupied attics or under-roof areas with cathedral ceilings, and metal roofed buildings may transmit noises to the building interior through the roof sheathing and building framing.

Where roof-transmitted sound reduction is most sought is in buildings located close to high noise areas such as under the flight path to airports.

Our photo of metal roofed homes (left) shows two older houses in Key West, Florida.

Types of Roof Noises & Sounds

Roof noises may be described as those attributed to an obvious source: the patter or even the roar of falling rain or hail, popping and cracking noises (perhaps due to thermal expansion and contraction of roof coverings, metal roofing, or roof structure), and transmitted noises from other external sources such as low-flying aircraft or nearby trains or auto & truck traffic from a nearby highway.

Accurate diagnosis of the source of roof noise transmission is important in deciding what remedy may work best. For example, check during rainfall to accurately determine the loudest sound source - you might find that more noise is transmitted to the building interior through skylights than through the roof surface itself. man ear as cutting noise levels in half, a reduction of over 20 decibels is significant. - Colbond [2]

We describe

One frequently cited disadvantage of metal roofing is that it generates a noticeable noise when struck by rain, hail, or even dropping acorns. If installed directly to purlins with no roof sheathing, the noise might be heard in the building interior.

However, when installed over a solid substrate, with normal levels of insulation, the noise should not be noticeably different than with other roofing types.



Sound Transmission Class - STC & OITC: Sound Transmission Loss Properties for Building Walls & Roofs

Definition of STC or Sound Transmission Class

STC or sound transmission class is defined as the level of reduction of sound transmission from outside noise sources to the building interior. Higher STC numbers mean higher resistance to sound transmission to the building interior, or as acousticians would describe it, higher STC means greater sound transmission loss between outdoors and the building interior. Typical STC values for metal buildings are STC=20 to STC=55.

OITC or Outdoor-Indoor Transmission Class describes the sound transmission loss properties of building exterior components like windows and walls against noise from traffic, trains, or low flying aircraft.

- General Steel Corporation [3]

See SOUND CONTROL in BUILDINGS for a series of articles on sound control in buildings.

Reader Question: (Jan 13, 2015) Bonnie said:

I had an Owens Corning roof installed with Tru Definition shingles. They installed a Ridge Vent with O'hagin vents and there are the T Top Vents. During a wind storm I hear a sound coming from the front of the house that sounds like a horn sound. It goes on and off for the entirety of the wind storm. Had the roofer here and he can't pinpoint what is making the horn sound or how to fix it. Ideas?



I'd start by temporarily blocking off the ridge vent by simply taping some plastic over it.


Siding Noises, Possible Causes, Effects, Cures for Vinyl Siding

This material moved to a new article

Stair and Step Noises in buildings

Stair noises in buildings include noisy stair treads that may creak or snap when stepped-on. See

Wall Noise Transmission Articles

Noise transmitted through walls (or ceilings) from mechanical rooms (boilers, furnaces) or utility rooms (washing machine, dryer) can be reduced by using good sound isolation construction and insulating materials.

See SOUND CONTROL in BUILDINGS for a series of articles on sound control in buildings.

Causes of Water heater noises or sounds in buildings

Water heater noise (C) Daniel Friedman

WATER HEATER NOISES in buildings include

  • Crackling or popping sounds as the water heater is warming up, especially if the water supply is high in mineral content, leading to mineral deposits on the bottom of the water heater or on electric water heating elements
  • Water heater noises & sounds:
    see WATER HEATER NOISE DIAGNOSIS, CURE for details, diagnosis, and cure of water heater sounds.

Watch out: water heater noises can indicate a high level of water heater scaling that increases water heating cost, reduces the quantity of hot water available, and can reduce water heater life. Water heater noises can also indicate that the heater has been set to a too-high temperature and may be unsafe, risking scalding or other hazards.

See these noise-related water heater articles:

Wind-caused noises in or at buildings

Wind Noise and wind-caused noises in buildings include a surprising number of mechanisms and sounds now discussed

Track Down Window & Door Related Noises in buildings

While sound-reducing or low-sound transmission windows using noise-reducing laminated glass and similar noise-reducing exterior or interior building doors are available, remember that as soon as you open a window for ventilation, the sound isolation benefit at that location is lost.

Sound-reducing doors should be of solid materials, have no glass windows or glazing, and should be sealed around the door perimeter with sound insulating foam or similar gaskets.

Continue reading at AIR LEAK NOISES in BUILDINGS or select a topic from the More Reading links or topic ARTICLE INDEX shown below.



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