Perception of infrasound: Difference between revisions

Revision as of 03:17, 21 July 2014

Revision as of 22:33, 21 July 2014

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{{Ethology}}

'''[[Infrasound]]''' is an anthropocentric term that refers to sounds containing some or all energy at frequencies lower than the low frequency end of human hearing threshold at 20&nbsp;Hz. It is known, however, that humans can perceive sounds below this frequency at very high pressure levels.<ref>{{cite journal|last=Yeowart|first=N. S.|author2=M. J. Evans|title=Thresholds of audibility for very low-frequency pure tones|journal=[[J. Acoust. Soc. Am.]]|year=1974|volume=55|pages=814–818|doi=10.1121/1.1914605}}</ref> Infrasound can come from many natural as well as man-made sources, including weather patterns, topographic features, ocean wave activity, thunderstorms, [[magnetic storms]], earthquakes, [[jet streams]], mountain ranges, and rocket launchings.<ref>{{cite journal|last=Cook|first=R. K.|title=Atmospheric sound propagation|journal=Atmospheric exploration by remote probes|year=1969|volume=2|pages=633–669}}</ref><ref>{{cite journal|last=Procunier|first=R. W.|title=Observations of acoustic aurora in the 1-16 Hz range|journal=Geophys. J. R. Astron. Soc.|year=1971|volume=26|pages=183–189}}</ref> Infrasounds are also present in the vocalizations of some animals. Low frequency sounds can travel for long distances with very little attenuation and can be detected hundreds of miles away from their sources.<ref name="Kreithen & Quine 1979">{{cite journal|last=Kreithen|first=M. L.|author2=D. B. Quine|title=Infrasound detection by the homing pigeon: A behavioral audiogram|journal=Journal of Physiology A|year=1979|issue=129|pages=1–4}}</ref><ref name="Langbauer et al 1990">{{cite journal|last=Langbauer|first=W. R.|coauthorsauthor2=K. B. Payne, |author3=R. A. Charif, |author4=E. M. Thomas |title=Responses of captive African elephants to playback of low-frequency calls|journal=Canadian Journal of Zoology|year=1990|issue=67|pages=2604–2607}}</ref>

== Mammals ==

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=== Elephants ===

Elephants are the terrestrial animal in which the production of infrasonic calls was discovered by Katy Payne.<ref>{{cite book|last=Payne|first=Katy|title=Silent Thunder: In the presence of Elephants|year=1998|publisher=Simon & Schuster|___location=New York}}</ref> The use of low frequency sounds to communicate over long distances may explain certain elephant behaviors that have previously puzzled observers. Elephant groups that are separated by several kilometers have been observed to travel in parallel or to change the direction simultaneously and move directly towards each other in order to meet.<ref name="Langbauer et al 1991">{{cite journal|last=Langbauer|first=W. R.|coauthorsauthor2=K. B. Payne, |author3=R. A. Charif, |author4=L. Rapaport, |author5=F. Osborn |title=African elephants respond to distant playbacks of low-frequency conspecific calls|journal=J. Exp. Biol.|year=1991|volume=157|pages=35–46}}</ref> The time of [[estrus]] for females is asynchronous, lasts only for a few days, and occurs only every several years. Nevertheless, males, which usually wander apart from female groups, rapidly gather from many directions to compete for a receptive female.<ref name="Langbauer et al 1991" /> Since infrasound can travel for very long distances, it has been suggested that calls in the infrasonic range might be important for long distance communication for such coordinated behaviors among separated elephants.<ref name="Langbauer et al 1991" /><ref name="Payne et al 1986">{{cite journal|last=Payne|first=K. B.|coauthorsauthor2=W. R. Langbauer, |author3=E. M. Thomas |title=Infrasonic calls of the Asian elephant (Elephas maximus|journal=Behav. Ecol. Sociobiol.|year=1986|volume=18|pages=297–301|doi=10.1007/bf00300007}}</ref>

==== Infrasound production and perception ====

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== Birds ==

Although birds do not produce vocalizations in the infrasonic range, reactions to infrasonic stimuli have been observed in several species, such as the homing pigeon, the guinea fowl, and the Asian grouse.<ref>{{cite journal|last=Yodlowski|first=M. L.|coauthorsauthor2=M. L. Kreithen, |author3=W. T. Keeton |title=Detection of atmospheric infrasound by pigeons|journal=Nature|year=1977|volume=265|pages=725–726|doi=10.1038/265725a0}}</ref><ref>{{cite journal|last=Theurich|first=M.|coauthorsauthor2=G. Langner, |author3=H. Scheich |title=Infrasound re-sponses in the midbrain of the Guinea Fowl|journal=Neurosci Lett|year=1984|volume=49|pages=81–86|doi=10.1016/0304-3940(84)90140-x}}</ref><ref>{{cite journal|last=Moss|first=R.|author2=I. Lockie|title=Infrasonic components in the song of the Capercaillie Tetrao urogallus|journal=Ibis|year=1979|volume=121|pages=95–97}}</ref> It is postulated that birds might use the detection of naturally occurring infrasound for long-range directional cues from distant landmarks, or for weather detection.<ref name="Quine 1981">{{cite journal|last=Quine|first=D. B.|title=Frequency shift discrimination: Can homing pigeons locate infrasounds by Doppler shifts?|journal=Journal of Comparative Physiology A|year=1981|volume=141|issue=2}}</ref>

=== Pigeons ===