Infrasound: What You Can't Hear CAN Hurt You

Scientific concepts, discoveries, and nature/physics phenomena mentioned

Infrasound basics and measurement

• Human hearing range: ~20 Hz to 20,000 Hz (lower frequencies are inaudible).
• Infrasound = pressure waves below ~20 Hz (often discussed in the ~10–20 Hz range).
• How it’s made audible for analysis: record with specialized equipment, then speed up the recording to shift it into the audible range.

Recording methods and equipment

• Modified seismograph-style sensing to capture very low-frequency vibration/pressure.
• Special infrasonic microphones, though many are typically specified only down to about ~20 Hz.
• When going below ~3–5 Hz, the argument is that you generally need seismographs/accelerometers rather than microphones.
• Raspberry Shake 3D (frequency measurement down to about 0.5 Hz) used for vibration monitoring.
• Use of open seismographic databases (EarthScope, SAGE, Raspberry Shake, USGS) and APIs for near-real-time data retrieval.

Biophysical and health effects (infrasound exposure)

• A meta-analysis (described) suggests infrasound can be harmful to health.
• Reported associations from “research strongly suggesting” effects include:
  • Headaches, fatigue, loss of concentration
  • Mood changes, depression
  • Sleeping disorders, panic disorders
  • Nausea, dizziness
• A highlighted peer-reviewed study (described rather than named) reports:
  • 100 dB infrasound (primarily around ~10 Hz) associated with roughly a 9% decrease in heart contraction force per 10 dB above a threshold (as described).
• Additional concern mentioned: animal research suggests negative effects on heart, liver, nervous system, and lungs.
• Caveat emphasized: the evidence base is incomplete due to difficulty and lack of research participation for such unpleasant exposures.

Example: “The Ghost in the Machine” explanation (infrasound and human perception)

• Research narrative attributed to Vic Tandy:
  • In a “haunted” lab, a fan produced infrasound around 18.9 Hz.
  • This frequency is said to overlap with a resonance related to the human eye (as presented).
  • When the fan/infrasound was reduced, people reportedly stopped reporting symptoms.
• Follow-up claim:
  • Measurement of strong infrasound at 18.9 Hz in another haunted site (a cellar in Coventry).
• The video frames these experiences as possibly explained by infrasound driving bodily/visual perceptual effects rather than paranormal causes.

Indoor resonance: Helmholtz resonance

• Helmholtz resonance can make low-frequency sound effects:
  • Louder indoors than outdoors
  • Produce throbbing/uncomfortable sensations (example given: partially opened rear window while driving)
  • Change or split frequencies, complicating identification of the original source.

Experimental infrasonic “cannon” studies and emotional/haunting reports

1. 2003 Liverpool Metropolitan Cathedral study (UK National Physical Laboratory)

   • A 23-ft infrasonic cannon tuned to 17.5 Hz
   • Played at ~90 dB during a live musical performance.
   • Results described:
     • Higher likelihood of discomfort when infrasonic tone was present.
     • 22% of participants reported strange/unexplainable effects (e.g., sadness, chills, fear/anxiety).

2. Goldsmiths College “haunted room” study (with EMF + infrasound)

   • Groups included:
     • Infrasound + EMF, EMF only, infrasound only, and a control (neither).
   • Sample sizes described:
     • Control 18 participants
     • Infrasound + EMF 18
     • EMF only 23
     • Infrasound only 20
   • Results described:
     • Control: average 3.7 “haunted experience” reports
     • Infrasound present: average 5.2 reports
     • About 80% exposed to infrasound or EMF for 50 minutes reported symptoms such as dizziness, odd sensations, tingling, out-of-body feelings, or feeling a presence.
   • The presenter criticizes study design as “fun but not well organized” and “not conclusive.”

Sound sources and propagation examples

• Infrastructure as dominant source (as framed):
  • Airports/train yards, wind turbines, building systems, etc.
• Wind turbines: generate infrasonic noise pollution; the video discusses controversy and funding claims about the research.
• Earth and natural phenomena:
  • A distant thunderstorm producing very strong infrasonic “symphony” (as heard after processing).
  • Tornado prediction/detection: early research described using infrasound.
  • Supervolcano/caldera region (Yellowstone): recordings from high altitude near geothermal/volcanic areas.
  • Hydrogen sulfide/hot vents:
    • Many geysers/hot springs appear inviting but are dangerous; a “pool” filled with sulfuric acid is described as observed in this segment.
• Propagation principle (why low frequencies travel far):
  • Lower frequencies → longer wavelengths
  • Result: less energy loss per distance → can travel farther.
  • The video uses analogies to light and mentions entropy/energy dissipation conceptually.
• Illustrated far-travel experiment using SpaceX launch:
  • Infrasound detected at distances up to >142 miles (West Hollywood).
  • Sound reportedly took over 11 minutes to reach a distant seismograph (as claimed).
  • Data collection approach: using multiple seismographs and accelerating audio for listening.

Methodology / workflow for capturing infrasonic events (as described)

• Record very low-frequency vibrations/pressure using:
  • Specialized microphones (when possible), otherwise seismographs/accelerometers
• If using seismographs:
  • Retrieve time-synchronized waveforms from open databases
  • Convert time-series vibration data into acoustic/pressure-related units (described as transforming into pascals / pressure oscillation units)
  • Accelerate/speed up playback to bring infrasonic content into audible range
• For event hunting:
  • Identify a likely loud source (e.g., SpaceX launch)
  • Compare signals across geographically separated stations
  • Listen/compute anomalies at distance to study propagation timing and travel

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List of researchers or sources featured (named in the subtitles)

• Vic Tandy (engineer/lecturer; “The Ghost in the Machine” narrative)
• UK National Physical Laboratory (institutional source for the 2003 infrasonic-cannon music study)
• Goldsmiths College (institutional source for the “haunted room” study)
• USGS (U.S. Geological Survey; referenced via seismographic data resources)
• EarthScope (open seismology data source)
• SAGE (open seismology data resource)
• Raspberry Shake (sensor network and data resources)