You're not crazy.
A scientific examination of low-frequency noise and infrasound.
Sound pressure waves below 20 Hz. Inaudible to most humans at moderate intensities but capable of producing vibrotactile sensations and physiological responses at high sound pressure levels (typically >100–110 dB).
Primary sensor: The inner ear (cochlea). Whole-body vibration can occur at extreme levels.
Wind turbines, HVAC systems, industrial machinery, and heavy transport generate low-frequency noise and infrasound. At residential distances these levels are typically well below 90 dB.
Multiple double-blind, sham-controlled studies find no consistent physiological or cognitive effects at real-world environmental exposure levels.
At very high intensities (typically >110 dB), infrasound can produce measurable physiological responses including body vibration, pressure sensations, and temporary changes in balance or discomfort.
These levels are rarely encountered outside laboratory, military, or industrial test environments.
The intensity of exposure is critical. Most community complaints involve levels far below those shown to produce measurable physiological effects in laboratory settings.
Peer-reviewed studies, standards, and technical references on low-frequency sound and infrasound.
Key ranges, effects, propagation, and detection tools (recreated from technical reference materials in the collection).
| Frequency | Audible? | Common Sources | Known/Reported Effects | Travel / Wall | Detection | Capable Speakers |
|---|---|---|---|---|---|---|
| 0.1–0.5 Hz | No | Ocean waves, seismic | Motion sickness (very high intensity) | Global / Yes | Research microbarometers | Military / purpose-built only |
| 0.5–1 Hz | No | Seismic, distant traffic, gravity waves | Unease, headache at extreme levels | 100s–1000s km / Yes | MOHO-AIR | Rotary subwoofer only |
| 1–4 Hz | No | Wind turbines, large HVAC, explosions | Anxiety, chest pressure, vestibular | 100s km / Yes | MOHO-AIR | Rotary / large servo subs |
| 4–10 Hz | No | Industrial, Theta brainwave range | Lethargy, cardiac effects, panic at high SPL | 10s–100s km / Yes | MOHO-AIR, ISO 7196 | High-end pro-audio infrasound subs |
| 10–20 Hz | Borderline | "Fear frequency" ~19 Hz, subwoofers | Pressure, tinnitus, visual disturbance, body vibration | Km-scale / Yes | MOHO-AIR, some apps | High-end consumer + pro infrasound subs |
| Frequency | Audible? | Common Sources | Known/Reported Effects | Travel / Wall | Detection | Capable Speakers |
|---|---|---|---|---|---|---|
| 20–30 Hz | Marginal | Subwoofers (primary complaint range) | Deep vibration, ear ringing, abdominal resonance | Good / Moderate | NSRTW_mk4, apps | Most consumer subwoofers |
| 30–50 Hz | Faint to audible | Subwoofers (most common complaint band) | Ear ringing, limb tingling, sleep disruption, irritability | Moderate / Good | Standard meters + apps | Virtually all consumer subwoofers |
| 50–70 Hz | Audible hum | Mains hum, HVAC, subwoofer crossover | Fatigue, concentration issues, persistent drone | Moderate | Class 2 SPL meters | All subwoofers + many full-range speakers |
Full detailed table with speaker examples and more ranges available in frequency_effects_reference_generic.pdf in the materials folder.
Reliable detection of residential infrasound requires specialized equipment. Consumer sound level meters and phone apps are generally inadequate below ~20–30 Hz.
The QuakeLogic AIR is one of the more accessible high-precision infrasound monitors designed for both home and research use. It features a 24-bit data processor, high-sensitivity differential pressure sensor, real-time waveform viewing, and 24-hour automated plotting.
Most “infrasound detectors” sold online and typical A-weighted meters do not accurately capture true infrasound. Proper measurement requires:
Standard dBA meters are structurally blind below 20 Hz. Professional or research-grade equipment is required for credible documentation.
Mass Loaded Vinyl is one of the more practical materials for reducing low-frequency sound transmission when installed correctly as part of a mass-air-mass system.
Correct Installation Principles:
Important: MLV helps with low-frequency noise but has limited effectiveness against very deep infrasound (<10–15 Hz) that travels primarily through the building structure rather than air. Complete isolation at true infrasound frequencies is extremely difficult in typical residential construction.
Additional practical steps discussed in the repository include source isolation (where possible), room layout adjustments to reduce resonance, and sealing major air leaks. Always combine multiple approaches and measure before/after when feasible.
Reliable detection requires proper equipment and methodology. Consumer “ghost hunting” or “EMF meter” devices sold for harassment detection are almost universally inadequate for the claimed phenomena.
Requires precision low-frequency microphones with flat response to at least 5–10 Hz, proper calibration, and software supporting Z- or G-weighting. Smartphone apps and consumer “infrasound detectors” cannot accurately measure true infrasound. Professional-grade systems are expensive.
Standard A-weighted sound level meters heavily underestimate low-frequency and infrasonic energy. Proper assessment often requires 1/3-octave band analysis down to low frequencies and long-term logging to capture fluctuating sources.
Tinnitus, vestibular disorders, sleep apnea, migraine variants, and functional neurological symptoms can produce very real distress. When measurements show no unusual acoustic energy, medical and psychological evaluation is the recommended path rather than assuming exotic external causes.
NYC alone logged 738,816 noise complaints via 311 in 2024 — an average of 2,000+ per day, up 19% from 2023. Residential noise accounted for roughly half. [Source: Brick Underground]
61% of apartment dwellers said they'd be more likely to move because of a bad neighbor. [Source: ApartmentAdvisor]
Over half of Americans are annoyed by their neighbors, with noise consistently cited as the top complaint. [Source: Lemonade]
A nationwide survey of 5,510 adults found that 45% of neighbors are loudest in the evening and 24.6% are loudest in the middle of the night. About 46% of respondents had never contacted their landlord about noise. [Source: The Waycroft]
Noise ranks among the top tenant complaints across all multifamily housing. Loud music, bass vibrations from modern speaker systems, stomping, barking dogs, and parties are the most cited. [Source: Azibo]
“Body vibration from neighbor's subwoofer set to frequencies they cannot hear... inner ear dysfunction aggravated by low-frequency hum... retaliatory infrasound after filing noise complaints.”
“A subwoofer playing 80 dB at sub-20 Hz frequencies may pressurize a neighbor's apartment more than the source apartment depending on building construction.”
“Two neighbors playing sub-bass / infrasound at all hours... described as using it as ‘a weapon’ causing eardrum pain. The sound penetrated the entire house and affected household pets.”
“A Florida woman whose neighbor subjected her to infrasonic harassment using daisy-chained speakers held to the floor, operated via smartphone.”
“A user reports 5 years of nightly infrasonic noise from a neighbor, with documented frequency spectrum analysis provided to police daily over weeks/months. Equipment costs for court-admissible measurement cited at approximately £6,000.”
“Multiple Quora threads document individuals reporting body vibration from neighbor's subwoofer set to frequencies they cannot hear, inner ear dysfunction aggravated by low-frequency hum, and retaliatory infrasound after filing noise complaints.”
“Forum members discuss the mechanics of infrasound harassment via subwoofers, noting that a subwoofer playing 80 dB at sub-20 Hz frequencies may pressurize a neighbor's apartment more than the source apartment depending on building construction.”
Nearly every noise-related homicide follows the same arc:
The critical failure point is steps 4–6: the absence of a legitimate resolution pathway.
These cases illustrate how unresolved low-frequency and neighbor noise disputes can escalate when formal channels fail. A peer-reviewed study (Journal of Public Economics) found a 4.1 dB noise increase produces a 6.6% increase in violent crime. Sources are contemporary news reporting and public records.
Selected guidelines, standards, measurement protocols, and key reference documents focused on infrasound and low-frequency noise.
Comprehensive guidance on environmental noise, including recommendations relevant to low-frequency sources.
International standard defining G-weighting for infrasound measurement and assessment.
Foundational review by Leventhall et al. covering perception, measurement, and effects of infrasound.
Professional documentation for the QuakeLogic AIR high-precision infrasound monitoring system (24-bit, high-sensitivity sensor, suitable for residential and research use). Includes user manual and technical datasheet.
You're not crazy. Precise language matters. These definitions are drawn from peer-reviewed acoustics literature and documented case patterns.
A structured, evidence-preserving approach if you suspect you are experiencing low-frequency noise harassment.
There is no feedback loop for the harasser. Their action is invisible; your visible reaction is the only reward. The goal is to separate your emotional response from your evidentiary response. Feel the anger privately. Document clinically. Do not give them the reaction they want.
Leave your home for 2–3 nights. Keep a detailed symptom log (sleep quality, headache, nausea, pressure, anxiety — rated 1–10). Return and compare. A clear, repeatable difference is powerful circumstantial evidence.
Start with smartphone accelerometer apps (not microphone-based). Use contact sensors or the Raspberry Boom for better data. Maintain a daily clinical log with timestamps. For court-admissible evidence, hire a certified acoustician with calibrated microbarometers.
Compile a timeline correlating symptoms with measurement data and neighbor activity. Get medical documentation of symptoms (do not lead with “my neighbor is attacking me”). Research your local noise ordinance, lease, and habitability laws. Consult a tenant rights or nuisance attorney before filing complaints.
Contact your landlord in writing with your documented evidence. Ask building staff to witness an episode. File repeated 311/noise complaints to create an official record. If the landlord fails to act, you may have grounds for habitability claims or lease termination.
Sleep in the room farthest from the suspected source. Use vibration-isolating pads under bed legs. Spend time away from the apartment when possible. Monitor your mental health and consider professional support — this is environmental trauma, not weakness.
A structured symptom-logging and evidence tool is in development. Join the waitlist for early access and updates.
You're not crazy. Compiled from peer-reviewed sources and documented case analyses. All answers include direct research citations and links. Use the filters to browse by topic.
Structured symptom logging, evidence export, and documentation tools for low-frequency noise cases.