HERD Library · popular science

Infrasound — the voice of the planet

Sound below the threshold of hearing pervades air, earth and ocean. Elephants and whales "talk" with it, pigeons navigate by it, and in it you can hear volcanoes thousands of kilometres away and meteors from space. Thirteen articles — each with its own bibliography.

We are building a network of cheap pressure sensors to hear dangerous events earlier. To explain why and how this works, we gathered everything science knows about infrasound into one open library. There are no formulas for the sake of formulas here — only verified facts, stories and links to primary sources.

How the library works

This is not one long page but a set of articles: each can be read on its own, and each has its own list of sources tagged peer-reviewed organization review history. Start with any card below.

Articles

01 · Basics

What infrasound is

Where hearing ends and the world of low frequencies begins. Wavelength, range, why it circles the planet.

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02 · Basics

What creates it

Volcanoes, earthquakes, storms, waterfalls, cities and jet aircraft — a map of infrasound sources.

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03 · Nature

Microbaroms — the voice of the sea

A constant "hum of the planet" near 0.2 Hz, born from colliding ocean waves.

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04 · History

Krakatoa, Tonga, Chelyabinsk

Waves that circled the Earth several times, and a meteor heard by instruments worldwide.

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05 · Animals

Elephants

Rumbles below our hearing travel for kilometres — through the air and through the ground, by feet.

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06 · Animals

Whales and the ocean sound channel

The loudest animals on the planet and a natural "waveguide" that carries their voice thousands of kilometres.

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07 · Animals

Pigeons and the map made of sound

The hypothesis that homing pigeons build an "acoustic map" of home from infrasound.

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08 · Animals

Jellyfish and storms

How brainless creatures "sense" a storm in advance — and where our R&D comes in.

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09 · Technology

How infrasound is detected

The global CTBTO network, microbarometers, array antennas and wind-noise filters.

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10 · Technology

A cheap sensor network

Can a meaningful event be caught with penny MEMS barometers? What the science says.

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11 · Weather

Weather, tornadoes, avalanches

A tornado "hums" before it touches the ground; avalanches are already caught by infrasound in real time.

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12 · Myths

Infrasound and health

The "fear frequency", wind turbines and the "Havana syndrome": what is confirmed and what is urban legend.

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13 · Mission

Early warning

What it is all for: a few minutes of lead time before a tsunami, eruption or meteor save lives.

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This is a living project, not a museum

HERD is building a sensor network and a low-frequency acoustics lab. The library grows together with the research.

Join R&D: jellyfish deterrent

Master bibliography

The full list of sources for the whole library. Each article has its own sub-list. Machine-readable index — infrasound-sources.json.

Show full list — 75 sources
  1. organization CTBTO. Infrasound monitoring (International Monitoring System). ctbto.org
  2. review Bedard A.J., Georges T.M. (2000). Atmospheric Infrasound. Physics Today 53(3). physicstoday.aip.org
  3. peer-reviewed Matoza R.S. et al. (2022). Global seismoacoustic observations of the January 2022 Hunga eruption, Tonga. Science 377. science.org
  4. peer-reviewed Le Pichon A. et al. (2013). The 2013 Russian fireball largest ever detected by CTBTO infrasound sensors. GRL 40. agupubs.wiley.com
  5. peer-reviewed Le Pichon A. et al. (2005). Infrasound associated with 2004–2005 Sumatra earthquakes and tsunami. GRL 32. agupubs.wiley.com
  6. review Garcés M. et al. (2005). Infrasound from the 2004 Sumatra earthquake and tsunami. ASA. acoustics.org
  7. peer-reviewed Bittner M. et al. (2010). Mesopause perturbations as a tsunami indicator. NHESS 10. nhess.copernicus.org
  8. history Symons G.J. (ed.) (1888). The Eruption of Krakatoa, and Subsequent Phenomena. Royal Society. archive.org
  9. reviewhistory Gabrielson T.B. (2004). Krakatoa and the Royal Society. Acoustics Today / ECHOES. acousticstoday.org
  10. pop-sci Cox A. (2014). The Sound So Loud That It Circled the Earth Four Times. Nautilus. nautil.us
  11. peer-reviewedhistory Longuet-Higgins M.S. (1950). A theory of the origin of microseisms. Phil. Trans. R. Soc. A 243. royalsocietypublishing.org
  12. peer-reviewed Waxler R., Gilbert K.E. (2006). Radiation of atmospheric microbaroms by ocean waves. JASA 119. pubs.aip.org
  13. peer-reviewed Payne K.B., Langbauer W.R., Thomas E.M. (1986). Infrasonic calls of the Asian elephant. Behav. Ecol. Sociobiol. 18. springer.com
  14. peer-reviewed O'Connell-Rodwell C.E. (2007). Keeping an 'ear' to the ground: seismic communication in elephants. Physiology 22. physiology.org
  15. peer-reviewed Mortimer B. et al. (2018). Classifying elephant behaviour through seismic vibrations. Current Biology 28. cell.com
  16. organization Elephant Listening Project, Cornell University. elephantlisteningproject.org
  17. organization NOAA Ocean Explorer. The SOFAR Channel. oceanexplorer.noaa.gov
  18. peer-reviewed Cummings W.C., Thompson P.O. (1971). Underwater sounds from the blue whale. JASA 50. pubs.aip.org
  19. peer-reviewed Širović A. et al. (2007). Blue and fin whale call source levels in the Southern Ocean. JASA 122. pubs.aip.org
  20. peer-reviewed Hagstrum J.T. (2013). Homing pigeons use loft-specific infrasound for navigation. J. Exp. Biol. 216. journals.biologists.com
  21. peer-reviewed Solé M. et al. (2016). Cnidarians sensitivity to sound after low-frequency noise exposure. Sci. Rep. 6. nature.com
  22. peer-reviewed Elbing B.R. et al. (2019). Infrasound from a tornado-producing storm. JASA 146. pubs.aip.org
  23. peer-reviewed Bedard A.J. (2005). Low-frequency acoustic energy from thunderstorm vortices. Mon. Wea. Rev. 133. journals.ametsoc.org
  24. peer-reviewed Marchetti E. et al. (2015). Infrasound array detection of snow avalanches. NHESS 15. nhess.copernicus.org
  25. peer-reviewed Mayer S. et al. (2020). Performance of an operational infrasound avalanche detection system. SLF. slf.ch
  26. organization Wyssen Avalanche Control. IDA® Infrasound Detection of Avalanches. wyssenavalanche.com
  27. review van Kamp I., van den Berg F. (2018). Health effects related to wind turbine sound and infrasound. Acoustics Australia 46. springer.com
  28. review McCunney R.J. et al. (2014). Wind turbines and health: a critical review. JOEM 56. journals.lww.com
  29. rebuttalorganization JASON/MITRE (2018). Analysis related to the Embassy Incidents (Havana syndrome). int.nyt.com
  30. peer-reviewedrebuttal Stubbs A.L., Montealegre-Z F. (2019). 'Sonic attacks' in Cuba match a cricket's calling song. bioRxiv. biorxiv.org
  31. organization Raspberry Shake & Boom — citizen seismo-acoustic sensors. raspberryshake.org
  32. organization Bosch Sensortec. BMP388 MEMS barometric pressure sensor. bosch-sensortec.com
  33. organization ARISE — Atmospheric dynamics Research InfraStructure in Europe. arise-project.eu
  34. peer-reviewedreview Fee D., Matoza R.S. (2013). An overview of volcano infrasound: from Hawaiian to Plinian, local to global. J. Volcanol. Geotherm. Res. 249. doi.org
  35. review Watson L.M. et al. (2022). Volcano infrasound: progress and future directions. Bull. Volcanol. 84. osti.gov
  36. peer-reviewedreview Møller H., Pedersen C.S. (2004). Hearing at low and infrasonic frequencies. Noise & Health 6(23). pubmed
  37. peer-reviewed Ardhuin F. et al. (2011). Ocean wave sources of seismic noise. J. Geophys. Res. Oceans 116. doi.org
  38. peer-reviewed Langbauer W.R. et al. (1991). African elephants respond to distant playbacks of low-frequency conspecific calls. J. Exp. Biol. 157. journals.biologists.com
  39. peer-reviewed Garstang M. et al. (2005). The daily cycle of low-frequency elephant calls and near-surface atmospheric conditions. Earth Interactions 9(14). journals.ametsoc.org
  40. peer-reviewed Edwards W.N., Brown P.G., ReVelle D.O. (2006). Estimates of meteoroid kinetic energies from infrasonic airwaves. J. Atmos. Sol.-Terr. Phys. 68. doi.org
  41. peer-reviewed McDonald M.A., Hildebrand J.A., Mesnick S. (2009). Worldwide decline in tonal frequencies of blue whale songs. Endang. Species Res. 9. int-res.com
  42. peer-reviewed Hedlin M.A.H., Alcoverro B., D'Spain G. (2003). Evaluation of rosette infrasonic noise-reducing spatial filters. JASA 114(4). doi.org
  43. peer-reviewed Assink J.D. et al. (2018). A seismo-acoustic analysis of the 2017 North Korean nuclear test. Seismol. Res. Lett. 89(6). geoscienceworld.org
  44. peer-reviewed Anderson J.F., Johnson J.B., Bowman D.C., Ronan T.J. (2018). The Gem infrasound logger and custom-built instrumentation. Seismol. Res. Lett. 89(1). doi.org
  45. peer-reviewed Marcillo O., Johnson J.B., Hart D. (2012). An inexpensive low-power low-noise infrasound sensor (infraBSU). J. Atmos. Ocean. Technol. 29(9). doi.org
  46. peer-reviewed Clive M.A. et al. (2024). Crowdsourcing human observations expands volcano monitoring (Raspberry Shake & Boom, Hunga 2022). Commun. Earth Environ. 5. doi.org
  47. peer-reviewed Cansi Y. (1995). An automatic seismic event processing for detection and location: the PMCC method. GRL 22(9). doi.org
  48. peer-reviewed Vergoz J. et al. (2022). IMS infrasound data products for atmospheric studies and civilian applications. Earth Syst. Sci. Data 14. essd.copernicus.org
  49. peer-reviewed Kubota T., Saito T., Nishida K. (2022). Global fast-traveling tsunamis driven by atmospheric Lamb waves on the 2022 Tonga eruption. Science 377(6601). doi.org
  50. peer-reviewed Streby H.M. et al. (2015). Tornadic storm avoidance behavior in breeding songbirds. Current Biology 25(1). doi.org
  51. peer-reviewed Bishop J.W. et al. (2022). Deep learning categorization of infrasound array data. JASA 152(4). doi.org
  52. peer-reviewed Jesus M.C. et al. (2024). Low-cost small-aperture array improves infrasound monitoring in the Azores. Pure Appl. Geophys. 181. doi.org
  53. peer-reviewed Den Ouden O.F.C. et al. (2021). The INFRA-EAR: low-cost mobile platform for geophysical monitoring (KNMI mini-MB). Atmos. Meas. Tech. 14. doi.org
  54. peer-reviewed Lamb O.D. et al. (2021). Assessing Raspberry Shake & Boom sensors for recording African elephant vocalizations. Front. Conserv. Sci. 1:630967. doi.org
  55. peer-reviewed Brissaud Q. et al. (2021). The first detection of an earthquake from a balloon using its acoustic signature. GRL 48. doi.org
  56. peer-reviewed Ravanelli M. et al. (2023). Tsunami and Lamb wave ionospheric signatures from the 2022 Hunga Tonga eruption (GNSS-TEC). Pure Appl. Geophys. 180. doi.org
  57. peer-reviewedreview Duarte C.M. et al. (2021). The soundscape of the Anthropocene ocean. Science 371(6529). doi.org
  58. peer-reviewedrebuttal Woith H., Petersen G.M., Hainzl S., Dahm T. (2018). Can animals predict earthquakes? BSSA 108(3A). doi.org
  59. peer-reviewed Allen R.M., Stogaitis M. et al. (2025). Global earthquake detection and warning using Android phones. Science 389(6757). doi.org
  60. peer-reviewed Johnson J.B. et al. (2023). Infrasound detection of approaching lahars. Sci. Rep. 13. doi.org
  61. peer-reviewed Marchetti E. et al. (2019). Infrasound array analysis of debris flow activity and implication for early warning. JGR Earth Surface 124. doi.org
  62. peer-reviewed Crichton F. et al. (2014). Health complaints and wind turbines: the nocebo expectations hypothesis. Front. Public Health 2:220. doi.org
  63. history Tandy V., Lawrence T.R. (1998). The ghost in the machine. J. Soc. Psychical Research 62. richardwiseman.com
  64. peer-reviewed von Muggenthaler E. (2000). Infrasonic and low-frequency vocalizations from Siberian and Bengal tigers. JASA 108(5). doi.org
  65. peer-reviewed Watkins W.A., Daher M.A. et al. (2004). Twelve years of tracking 52-Hz whale calls. Deep-Sea Research I 51. doi.org
  66. peer-reviewed Ripepe M. et al. (2018). Infrasonic early warning system for explosive eruptions. JGR Solid Earth 123. doi.org
  67. peer-reviewed Ripepe M. et al. (2021). Dense seismo-acoustic network warning of the 2019 paroxysmal Stromboli eruptions. Sci. Rep. 11. doi.org
  68. organizationrebuttal NOAA PMEL Acoustics. Icequakes ("Bloop"). pmel.noaa.gov
  69. peer-reviewed Mack A.L., Jones J. (2003). Low-frequency vocalizations by cassowaries (Casuarius spp.). The Auk 120(4). doi.org
  70. peer-reviewed Hetzer C.H., Gilbert K.E., Waxler R., Talmadge C.L. (2008). Infrasound from hurricanes: dependence on the ocean surface wave field. GRL 35. doi.org
  71. peer-reviewed De Carlo M., Ardhuin F., Le Pichon A. (2020). Atmospheric infrasound generation by ocean waves in finite depth. Geophys. J. Int. 221. doi.org
  72. peer-reviewed Reber S.A. et al. (2017). Formants provide honest acoustic cues to body size in American alligators. Sci. Rep. 7. doi.org
  73. peer-reviewed Freeman A.R., Hare J.F. (2015). Infrasound in mating displays: a peacock's tale. Animal Behaviour 102. doi.org
  74. peer-reviewed Barklow W.E. (2004). Low-frequency sounds and amphibious communication in Hippopotamus amphibius. JASA 115. doi.org
  75. peer-reviewed Wilson C.R., Olson J.V. (2005). High trace-velocity infrasound from pulsating auroras at Fairbanks, Alaska. GRL 32. doi.org