Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants
Sound production mechanisms set the parameter space available for transmitting biologically relevant information in vocal signals. Low–frequency rumbles play a crucial role in coordinating social interactions in elephants’ complex fission–fusion societies. By emitting rumbles through either the oral...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/12/16/2119 |
| _version_ | 1827601052984147968 |
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| author | Veronika C. Beeck Gunnar Heilmann Michael Kerscher Angela S. Stoeger |
| author_facet | Veronika C. Beeck Gunnar Heilmann Michael Kerscher Angela S. Stoeger |
| author_sort | Veronika C. Beeck |
| collection | DOAJ |
| description | Sound production mechanisms set the parameter space available for transmitting biologically relevant information in vocal signals. Low–frequency rumbles play a crucial role in coordinating social interactions in elephants’ complex fission–fusion societies. By emitting rumbles through either the oral or the three-times longer nasal vocal tract, African elephants alter their spectral shape significantly. In this study, we used an acoustic camera to visualize the sound emission of rumbles in Asian elephants, which have received far less research attention than African elephants. We recorded nine adult captive females and analyzed the spectral parameters of 203 calls, including vocal tract resonances (formants). We found that the majority of rumbles (64%) were nasally emitted, 21% orally, and 13% simultaneously through the mouth and trunk, demonstrating velopharyngeal coupling. Some of the rumbles were combined with orally emitted roars. The nasal rumbles concentrated most spectral energy in lower frequencies exhibiting two formants, whereas the oral and mixed rumbles contained higher formants, higher spectral energy concentrations and were louder. The roars were the loudest, highest and broadest in frequency. This study is the first to demonstrate velopharyngeal coupling in a non-human animal. Our findings provide a foundation for future research into the adaptive functions of the elephant acoustic variability for information coding, localizability or sound transmission, as well as vocal flexibility across species. |
| first_indexed | 2024-03-09T04:47:47Z |
| format | Article |
| id | doaj.art-4caa8a4853ad4c5b9652985cee58c915 |
| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-03-09T04:47:47Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj.art-4caa8a4853ad4c5b9652985cee58c9152023-12-03T13:13:41ZengMDPI AGAnimals2076-26152022-08-011216211910.3390/ani12162119Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian ElephantsVeronika C. Beeck0Gunnar Heilmann1Michael Kerscher2Angela S. Stoeger3Department of Behavioural and Cognitive Biology, University of Vienna, 1030 Vienna, AustriaMecalc Technologies GmbH, 12487 Berlin, GermanyMecalc Technologies GmbH, 12487 Berlin, GermanyDepartment of Behavioural and Cognitive Biology, University of Vienna, 1030 Vienna, AustriaSound production mechanisms set the parameter space available for transmitting biologically relevant information in vocal signals. Low–frequency rumbles play a crucial role in coordinating social interactions in elephants’ complex fission–fusion societies. By emitting rumbles through either the oral or the three-times longer nasal vocal tract, African elephants alter their spectral shape significantly. In this study, we used an acoustic camera to visualize the sound emission of rumbles in Asian elephants, which have received far less research attention than African elephants. We recorded nine adult captive females and analyzed the spectral parameters of 203 calls, including vocal tract resonances (formants). We found that the majority of rumbles (64%) were nasally emitted, 21% orally, and 13% simultaneously through the mouth and trunk, demonstrating velopharyngeal coupling. Some of the rumbles were combined with orally emitted roars. The nasal rumbles concentrated most spectral energy in lower frequencies exhibiting two formants, whereas the oral and mixed rumbles contained higher formants, higher spectral energy concentrations and were louder. The roars were the loudest, highest and broadest in frequency. This study is the first to demonstrate velopharyngeal coupling in a non-human animal. Our findings provide a foundation for future research into the adaptive functions of the elephant acoustic variability for information coding, localizability or sound transmission, as well as vocal flexibility across species.https://www.mdpi.com/2076-2615/12/16/2119elephantvocal communicationsource-filter theorysound productionformantvocal tract |
| spellingShingle | Veronika C. Beeck Gunnar Heilmann Michael Kerscher Angela S. Stoeger Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants Animals elephant vocal communication source-filter theory sound production formant vocal tract |
| title | Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants |
| title_full | Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants |
| title_fullStr | Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants |
| title_full_unstemmed | Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants |
| title_short | Sound Visualization Demonstrates Velopharyngeal Coupling and Complex Spectral Variability in Asian Elephants |
| title_sort | sound visualization demonstrates velopharyngeal coupling and complex spectral variability in asian elephants |
| topic | elephant vocal communication source-filter theory sound production formant vocal tract |
| url | https://www.mdpi.com/2076-2615/12/16/2119 |
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