Editing Bioacoustics

{{Short description|Study of sound relating to biology}}
[[File:Sonogram L luscinia L megarhynchos.png|thumb|[[Spectrogram]]s of [[Thrush nightingale]] (''Luscinia luscinia'') and [[Common nightingale]] (''Luscinia megarhynchos'') singing help to reliably distinguish these two species by voice.]]
'''Bioacoustics''' is a cross-disciplinary [[science]] that combines [[biology]] and [[acoustics]]. Usually it refers to the investigation of [[sound]] production, dispersion and reception in [[animal]]s (including [[humans]]).<ref>{{cite web |url=http://www.bioacoustics.info/ |title=Bioacoustics - the International Journal of Animal Sound and its Recording |publisher=Taylor & Francis |access-date=31 July 2012}}</ref> This involves [[neurophysiology|neurophysiological]] and [[anatomy|anatomical]] basis of sound production and detection, and relation of acoustic [[Signal (electrical engineering)|signals]] to the [[Transmission medium|medium]] they disperse through. The findings provide clues about the [[evolution]] of acoustic mechanisms, and from that, the evolution of animals that employ them.

In [[underwater acoustics]] and [[fisheries acoustics]] the term is also used to mean the effect of [[plants]] and animals on sound propagated underwater, usually in reference to the use of [[sonar]] technology for [[biomass]] estimation.<ref>Medwin H. & Clay C.S. (1998). ''Fundamentals of Acoustical Oceanography'', [[Academic Press]]</ref><ref name="SimmondsMacLennan">Simmonds J. & MacLennan D. (2005). ''Fisheries Acoustics: Theory and Practice'', second edition. [[Wiley-Blackwell|Blackwell]]</ref> The study of substrate-borne vibrations used by animals is considered by some a distinct field called [[biotremology]].<ref name="Primer">{{cite journal |last1=Hill |first1=Peggy S.M. |last2=Wessel |first2=Andreas |year=2016 |title=Biotremology |journal=[[Current Biology]] |volume=26 |issue=5 |pages=R187–R191 |doi=10.1016/j.cub.2016.01.054 |pmid=26954435|doi-access=free |bibcode=2016CBio...26.R187H }}</ref>

==History==
For a long time humans have employed animal sounds to recognise and find them. Bioacoustics as a [[scientific discipline]] was established by the [[Slovenes|Slovene]] biologist [[Ivan Regen]] who began systematically to study [[insect]] sounds. In 1925 he used a special [[stridulation|stridulatory]] device to play in a duet with an insect. Later, he put a male [[Cricket (insect)|cricket]] behind a microphone and female crickets in front of a loudspeaker. The females were not moving towards the male but towards the loudspeaker.<ref>Kočar T. (2004). ''[http://www.gea-on.net/clanek.asp?ID=522 Kot listja in kobilic]'' (''As many as leaves and grasshoppers''). [[GEA (magazine)|GEA]], October 2004. [[Mladinska knjiga]], [[Ljubljana]] {{in lang|sl}}</ref> Regen's most important contribution to the field apart from realization that insects also detect airborne sounds was the discovery of [[tympanal organ]]'s function.<ref>{{cite encyclopedia |url=http://www.britannica.com/EBchecked/topic/555378/sound-reception/64794/Evidence-of-hearing-and-communication-in-insects |title=Sound reception: Evidence of hearing and communication in insects |first=Ernest |last=Glen Wever |encyclopedia=Britannica online |year=2008 |access-date=2008-09-25}}</ref>

Relatively crude electro-mechanical devices available at the time (such as [[phonograph]]s) allowed only for crude appraisal of signal properties. More accurate measurements were made possible in the second half of the 20th century by advances in electronics and utilization of devices such as [[oscilloscope]]s and digital recorders.

The most recent advances in bioacoustics concern the relationships among the animals and their acoustic environment and the impact of anthropogenic [[Noise (environmental)|noise]]. Bioacoustic techniques have recently been proposed as a non-destructive method for estimating [[biodiversity]] of an area.<ref>{{cite journal
| author      = Sueur J. |author2=Pavoine S. |author3=Hamerlynck O. |author4=Duvail S.
| editor1-last      = Reby
| date        = December 30, 2008
| editor1-first      = David
| title       = Rapid Acoustic Survey for Biodiversity Appraisal
| journal     = [[PLoS ONE]]
| volume      = 3
| issue       = 12
| pages       = e4065
| doi         = 10.1371/journal.pone.0004065
| pmid      = 19115006
| pmc      = 2605254
|bibcode = 2008PLoSO...3.4065S |doi-access=free }}</ref>

== Importance ==
In the terrestrial environment, animals often use light for sensing distance, since light propagates well through air. Underwater sunlight only reaches to tens of meters depth. However, sound propagates readily through water and across considerable distances. Many marine animals can see well, but using hearing for communication, and sensing distance and location. Gauging the relative importance of audition versus vision in animals can be performed by comparing the number of [[Auditory Nerve|auditory]] and [[Optic nerve|optic nerves]]. 

Since the 1950s to 1960s, studies on dolphin echolocation behavior using high frequency click sounds revealed that many different marine mammal species make sounds, which can be used to detect and identify species under water. Much research in bioacoustics has been funded by [[naval]] research organizations, as biological sound sources can interfere with [[military]] uses underwater.<ref>{{Citation |last=Tyack |first=P. L. |title=Bioacoustics |date=2001-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780123744739004367 |encyclopedia=Encyclopedia of Ocean Sciences (Second Edition) |pages=357–363 |editor-last=Steele |editor-first=John H. |place=Oxford |publisher=Academic Press |language=en |doi=10.1016/b978-012374473-9.00436-7 |isbn=978-0-12-374473-9 |access-date=2022-06-17|url-access=subscription }}</ref>

==Methods==
[[Image:Underwater-microphone hg.jpg|thumb|80px|right|Hydrophone]]
Listening is still one of the main methods used in bioacoustical research. Little is known about neurophysiological processes that play a role in production, detection and interpretation of sounds in animals, so [[ethology|animal behaviour]] and the signals themselves are used for gaining insight into these processes. 

Bioacoustics has also helped to pave the way for new emerging methods such as ecoacoustics (or [[acoustic ecology]]),<ref>{{Citation |last1=Farina |first1=Almo |title=Ecoacoustics: A New Science |date=2017 |work=Ecoacoustics |pages=1–11 |url=https://onlinelibrary.wiley.com/doi/10.1002/9781119230724.ch1 |access-date=2025-01-21 |publisher=John Wiley & Sons, Ltd |language=en |doi=10.1002/9781119230724.ch1 |isbn=978-1-119-23072-4 |last2=Gage |first2=Stuart H.|url-access=subscription }}</ref> an interdisciplinary field of research that studies the sounds produced by ecosystems, including biological, geophysical and anthropogenic sources. It examines how these sounds interact with the environment, providing insights into biodiversity, habitat health and ecological processes. By analysing soundscapes, ecoacoustics helps monitor environmental changes, assess conservation efforts and detect human impacts on natural systems.

===Acoustic signals===
[[Image:Akhumps_128_016_0_500c.png|thumb|200px|left|[[Spectrogram]] (above) and [[oscillogram]] (below) of the [[humpback whale]]'s calls]]
An experienced observer can use animal sounds to recognize a "singing" animal [[species]], its location and condition in nature. Investigation of animal sounds also includes signal recording with electronic recording equipment. Due to the wide range of signal properties and media they propagate through, specialized equipment may be required instead of the usual [[microphone]], such as a [[hydrophone]] (for underwater sounds), detectors of [[ultrasound]] (very high-[[frequency]] sounds) or [[infrasound]] (very low-frequency sounds), or a [[laser Doppler vibrometer|laser vibrometer]] (substrate-borne vibrational signals). [[Computer]]s are used for storing and analysis of recorded sounds. Specialized sound-editing [[software]] is used for describing and sorting signals according to their [[amplitude|intensity]], [[frequency]], duration and other parameters.

Animal sound collections, managed by [[museum of natural history|museums of natural history]] and other institutions, are an important tool for systematic investigation of signals. Many effective automated methods involving signal processing, data mining, machine learning and artificial intelligence<ref>{{Cite magazine |last=Rodrigues |first=Meghie |date=13 January 2024 |title=The song of a missing bird may help scientists find it |url=<!-- citation from paper magazine --> |department=The Science Life |magazine=[[Science News]] |page=4}}</ref> techniques have been developed to detect and classify the bioacoustic signals.<ref>M. Pourhomayoun, P. Dugan, M. Popescu, and C. Clark, “Bioacoustic Signal Classification Based on Continuous Region Features, Grid Masking Features and Artificial Neural Network,” International Conference on Machine Learning (ICML), 2013.</ref>

===Sound production, detection, and use in animals===
[[Scientist]]s in the field of bioacoustics are interested in anatomy and neurophysiology of [[organ (anatomy)|organs]] involved in sound production and detection, including their shape, [[muscle]] action, and activity of [[neuronal network]]s involved. Of special interest is coding of signals with [[action potential]]s in the latter.

But since the methods used for neurophysiological research are still fairly complex and understanding of relevant processes is incomplete, more trivial methods are also used. Especially useful is observation of behavioural responses to acoustic signals. One such response is [[phonotaxis]] – directional movement towards the signal source. By observing response to well defined signals in a controlled environment, we can gain insight into signal function, [[Stimulus (physiology)|sensitivity]] of the hearing apparatus, [[noise]] filtering capability, etc.

===Biomass estimation===
{{main|Hydroacoustics}}
Biomass estimation is a method of detecting and quantifying [[fish]] and other marine organisms using [[sonar]] technology.<ref name="SimmondsMacLennan"/> As the sound pulse travels through water it encounters objects that are of different density than the surrounding medium, such as fish, that reflect sound back toward the sound source. These echoes provide information on fish size, location, and [[abundance (ecology)|abundance]]. The basic components of the scientific [[echo sounder]] hardware function is to transmit the sound, receive, filter and amplify, record, and analyze the echoes. While there are many manufacturers of commercially available "fish-finders," quantitative analysis requires that measurements be made with [[calibration|calibrated]] echo sounder equipment, having high [[signal-to-noise ratio]]s.

==Animal sounds==
[[Image:Hanenkraaiwedstrijd (cropped2).jpg|thumb|right|200px|[[Bergischer Kräher|Bergische Crower]] crowing]]

[[Image:Birdsinging03182006.JPG|thumb|right|200px|[[European starling]] singing]]
Sounds used by animals that fall within the scope of bioacoustics include a wide range of frequencies and media, and are often not "''sound''" in the narrow sense of the word (i.e. [[compression wave]]s that propagate through [[air]] and are detectable by the human [[ear]]). [[Tettigoniidae|Katydid cricket]]s, for example, communicate by sounds with frequencies higher than 100 [[Hertz|kHz]], far into the ultrasound range.<ref>{{cite journal | last1 = Mason | first1 = A.C. | last2 = Morris | first2 = G.K. | last3 = Wall | first3 = P. | year = 1991 | title = High Ultrasonic Hearing and Tympanal Slit Function in Rainforest Katydids | journal = Naturwissenschaften | volume = 78 | issue = 8| pages = 365–367 | doi = 10.1007/bf01131611 | bibcode = 1991NW.....78..365M | s2cid = 40255816 }}</ref> Lower, but still in ultrasound, are sounds used by [[bat]]s for [[animal echolocation#Bats|echolocation]]. A segmented marine worm ''[[Leocratides kimuraorum]]'' produces one of the loudest popping sounds in the ocean at 157&nbsp;dB, frequencies 1–100&nbsp;kHz, similar to the [[Alpheidae|snapping shrimps]].<ref>{{Cite journal|last1=Goto|first1=Ryutaro|last2=Hirabayashi|first2=Isao|last3=Palmer|first3=A. Richard|date=2019-07-08|title=Remarkably loud snaps during mouth-fighting by a sponge-dwelling worm|journal=Current Biology|language=en|volume=29|issue=13|pages=R617–R618|doi=10.1016/j.cub.2019.05.047|issn=0960-9822|pmid=31287974|doi-access=free|bibcode=2019CBio...29.R617G }}</ref><ref>{{Cite web|url=https://www.livescience.com/65945-tiny-worms-emit-loud-noise.html|title=Tiny Fighting Worms Make One of the Loudest Sounds in the Ocean|last=Saplakoglu 2019-07-16T15:48:02Z|first=Yasemin|website=livescience.com|date=16 July 2019 |language=en|access-date=2019-12-28}}</ref> On the other side of the frequency spectrum are low frequency-vibrations, often not detected by [[Hearing (sense)|hearing]] organs, but with other, less specialized sense organs. The examples include [[ground vibrations]] produced by [[elephants]] whose principal frequency component is around 15&nbsp;Hz, and low- to medium-frequency substrate-borne vibrations used by most [[insect]] [[order (biology)|orders]].<ref>{{cite journal | last1 = Virant-Doberlet | first1 = M. | last2 = Čokl | first2 = A. | year = 2004 | title = Vibrational communication in insects | journal = Neotropical Entomology | volume = 33 | issue = 2| pages = 121–134 | doi = 10.1590/s1519-566x2004000200001 | doi-access = free }}</ref> Many animal sounds, however, do fall within the frequency range detectable by a human ear, between 20 and 20,000&nbsp;Hz.<ref name="Mikula">{{cite journal|author1=Mikula, P.|author2=Valcu, M.|author3=Brumm, H.|author4=Bulla, M.|author5=Forstmeier, W.|author6= Petrusková, T.|author7=Kempenaers, B. |author8= Albrecht, T.|name-list-style=amp|year=2021|title= A global analysis of song frequency in passerines provides no support for the acoustic adaptation hypothesis but suggests a role for sexual selection|journal=Ecology Letters|volume=24|issue=3|pages=477–486|doi= 10.1111/ele.13662|pmid=33314573|doi-access=free|bibcode=2021EcolL..24..477M }}</ref> Mechanisms for sound production and detection are just as diverse as the signals themselves.

==Plant sounds==
In a series of scientific journal articles published between 2013 and 2016, [[Monica Gagliano]] of the [[University of Western Australia]] extended the science to include [[plant bioacoustics]].<ref>{{cite web |url=http://www.monicagagliano.com |title=Plant Behavior & Cognition {{!}} Monica Gagliano {{!}} Scientific Research |website=www.monicagagliano.com |access-date=26 December 2016}}{{title missing|date=May 2022}}</ref>

==See also==
{{div col|colwidth=22em}}

* [[Acoustic ecology]]
* [[Acoustical oceanography]]
* [[Animal communication]]
* [[Animal language]]
* [[Anthropophony]]
* [[Biomusic]]
* [[Biophony]]
* [[Diffusion (acoustics)]]
* [[Field recording]]
* [[Frog hearing and communication]]
* [[List of animal sounds]]
* [[List of Bioacoustics Software]]
* [[Music therapy]]
* [[Natural sounds]]
* [[Soundscape ecology]]
* [[Underwater acoustics]]
* [[Vocal learning]]
* [[Whale sound]]
* [[Zoomusicology]]

*[[Phonology]]{{div col end}}

==References==
{{reflist}}

==Further reading==
* Ewing A.W. (1989): ''Arthropod bioacoustics: Neurobiology and behaviour''. Edinburgh: Edinburgh University Press. {{ISBN|0-7486-0148-1}}
* Fletcher N. (2007): ''[https://www.springer.com/cda/content/document/cda_downloaddocument/sample%20chapter.pdf?SGWID=0-0-45-279393-p123153395 Animal Bioacoustics]''. IN: Rossing T.D. (ed.): ''[https://www.springer.com/east/home/generic/search/results?SGWID=5-40109-22-153743469-0 Springer Handbook of Acoustics]'', [[Springer Science+Business Media|Springer]]. {{ISBN|978-0-387-33633-6}}

==External links==
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*[https://tcabasa.org/ ASA Animal Bioacoustics Technical Committee]
*[http://bio.acousti.ca/ BioAcoustica]: Wildlife Sounds Database
* [http://www.bl.uk/reshelp/findhelprestype/sound/wildsounds/wildlife.html The British Library Sound Archive] has 150,000 recordings of over 10,000 species.
* [http://www.ibac.info/ International Bioacoustics Council] links to many bioacoustics resources.
* [https://web.archive.org/web/20060822192437/http://blb.biosci.ohio-state.edu/ Borror Laboratory of Bioacoustics] at The Ohio State University has a large archive of animal sound recordings.
* [http://www.bl.uk/listentonature Listen to Nature] {{Webarchive|url=https://web.archive.org/web/20160922002023/http://www.bl.uk/listentonature |date=2016-09-22 }} 400 examples of animal songs and calls
* [http://www.wildlife-sound.org/ Wildlife Sound Recording Society]
* [http://www.birds.cornell.edu/brp/?lk=lpro/ Bioacoustic Research Program] at the [[Cornell Lab of Ornithology]] distributes a number of different free bioacoustics synthesis & analysis programs.
* [http://www.birds.cornell.edu/macaulaylibrary/?lk=lpro Macaulay Library] at the [[Cornell Lab of Ornithology]] is the world's largest collection of animal sounds and associated video.
* [http://www.xeno-canto.org/ Xeno-canto] A collection of bird vocalizations from around the world.

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{{Animal communication}}
{{hydroacoustics}}
{{Music cognition}}

{{Authority control}}

[[Category:Acoustics]]
[[Category:Zoosemiotics]]
[[Category:Soundscape ecology]]
[[Category:Sound]]
[[Category:Noise]]
[[Category:Hearing]]