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Abstract
This review provides a comprehensive compilation, from a digital image processing point of view of the most important techniques currently developed to characterize and quantify the vibration behaviour of the vocal folds, along with a detailed description of the laryngeal image modalities currently used in the clinic. The review presents an overview of the most significant glottal-gap segmentation and facilitative playbacks techniques used in the literature for the mentioned purpose, and shows the drawbacks and challenges that still remain unsolved to develop robust vocal folds vibration function analysis tools based on digital image processing.
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2
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Kumar SP, Švec JG. Kinematic model for simulating mucosal wave phenomena on vocal folds. Biomed Signal Process Control 2019. [DOI: 10.1016/j.bspc.2018.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Kim IG, Park MR, Choi YH, Choi JS, Ahn HJ, Kwon SK, Lee JH. Regeneration of Paralyzed Vocal Fold by the Injection of Plasmid DNA Complex-Loaded Hydrogel Bulking Agent. ACS Biomater Sci Eng 2019; 5:1497-1508. [DOI: 10.1021/acsbiomaterials.8b01541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- In Gul Kim
- Department of Otorhinolaryngology—Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Mi Ri Park
- Department of Advanced Materials and Chemical Engineering, Hannam University, Daejeon 34054, Republic of Korea
| | - Young Hwan Choi
- Department of Otorhinolaryngology—Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Ji Suk Choi
- Department of Otorhinolaryngology—Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Hee-Jin Ahn
- Department of Otorhinolaryngology—Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Seong Keun Kwon
- Department of Otorhinolaryngology—Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Jin Ho Lee
- Department of Advanced Materials and Chemical Engineering, Hannam University, Daejeon 34054, Republic of Korea
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Baotic A, Garcia M, Boeckle M, Stoeger A. Field Propagation Experiments of Male African Savanna Elephant Rumbles: A Focus on the Transmission of Formant Frequencies. Animals (Basel) 2018; 8:E167. [PMID: 30274350 PMCID: PMC6210294 DOI: 10.3390/ani8100167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/23/2018] [Accepted: 09/25/2018] [Indexed: 11/16/2022] Open
Abstract
African savanna elephants live in dynamic fission⁻fusion societies and exhibit a sophisticated vocal communication system. Their most frequent call-type is the 'rumble', with a fundamental frequency (which refers to the lowest vocal fold vibration rate when producing a vocalization) near or in the infrasonic range. Rumbles are used in a wide variety of behavioral contexts, for short- and long-distance communication, and convey contextual and physical information. For example, maturity (age and size) is encoded in male rumbles by formant frequencies (the resonance frequencies of the vocal tract), having the most informative power. As sound propagates, however, its spectral and temporal structures degrade progressively. Our study used manipulated and resynthesized male social rumbles to simulate large and small individuals (based on different formant values) to quantify whether this phenotypic information efficiently transmits over long distances. To examine transmission efficiency and the potential influences of ecological factors, we broadcasted and re-recorded rumbles at distances of up to 1.5 km in two different habitats at the Addo Elephant National Park, South Africa. Our results show that rumbles were affected by spectral⁻temporal degradation over distance. Interestingly and unlike previous findings, the transmission of formants was better than that of the fundamental frequency. Our findings demonstrate the importance of formant frequencies for the efficiency of rumble propagation and the transmission of information content in a savanna elephant's natural habitat.
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Affiliation(s)
- Anton Baotic
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna 1090, Austria.
| | - Maxime Garcia
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna 1090, Austria.
- ENES Lab, Neuro-PSI, CNRS UMR 9197, University of Lyon/Saint Etienne, 42023 Saint Etienne, France.
| | - Markus Boeckle
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK.
- Department of Psychotherapy, Bertha von Suttner University, St. Poelten 3100, Austria.
| | - Angela Stoeger
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna 1090, Austria.
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Rasmussen JH, Herbst CT, Elemans CPH. Quantifying syringeal dynamics in vitro using electroglottography. ACTA ACUST UNITED AC 2018; 221:jeb.172247. [PMID: 29880637 DOI: 10.1242/jeb.172247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 05/30/2018] [Indexed: 11/20/2022]
Abstract
The complex and elaborate vocalizations uttered by many of the 10,000 extant bird species are considered a major driver in their evolutionary success, warranting study of the underlying mechanisms of vocal production. Additionally, birdsong has developed into a highly productive model system for vocal imitation learning and motor control, where, in contrast to humans, we have experimental access to the entire neuromechanical control loop. In human voice production, complex laryngeal geometry, vocal fold tissue properties, airflow and laryngeal musculature all interact to ultimately control vocal fold kinematics. Quantifying vocal fold kinematics is thus critical to understanding neuromechanical control of voiced sound production, but in vivo imaging of vocal fold kinematics in birds is experimentally challenging. Here, we adapted and tested electroglottography (EGG) as a novel tool for examining vocal fold kinematics in the avian vocal organ, the syrinx. We furthermore imaged and quantified syringeal kinematics in the pigeon (Columba livia) syrinx with unprecedented detail. Our results show that EGG signals predict (1) the relative amount of contact between the avian equivalent of vocal folds and (2) essential parameters describing vibratory kinematics, such as fundamental frequency, and timing of syringeal opening and closing events. As such, EGG provides novel opportunities for measuring syringeal vibratory kinematic parameters in vivo Furthermore, the opportunity for imaging syringeal vibratory kinematics from multiple planar views (horizontal and coronal) simultaneously promotes birds as an excellent model system for studying kinematics and control of voiced sound production in general, including in humans and other mammals.
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Affiliation(s)
- Jeppe H Rasmussen
- Department of Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Christian T Herbst
- Department of Cognitive Biology, University of Vienna, 1090 Vienna, Austria
| | - Coen P H Elemans
- Department of Biology, University of Southern Denmark, 5230 Odense, Denmark
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Döllinger M, Kniesburges S, Berry DA, Birk V, Wendler O, Dürr S, Alexiou C, Schützenberger A. Investigation of phonatory characteristics using ex vivo rabbit larynges. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 144:142. [PMID: 30075689 PMCID: PMC6037535 DOI: 10.1121/1.5043384] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Quantitative analysis of phonatory characteristics of rabbits has been widely neglected. However, preliminary studies established the rabbit larynx as a potential model of human phonation. This study reports quantitative data on phonation using ex vivo rabbit larynx models to achieve more insight into dependencies of three main components of the phonation process, including airflow, vocal fold dynamics, and the acoustic output. Sustained phonation was induced in 11 ex vivo rabbit larynges. For 414 phonatory conditions, vocal fold vibrations, acoustic, and aerodynamic parameters were analyzed as functions of longitudinal vocal fold pre-stress, applied air flow, and glottal closure insufficiency. Dimensions of the vocal folds were measured and histological data were analyzed. Glottal closure characteristics improved for increasing longitudinal pre-stress and applied airflow. For the subglottal pressure signal only the cepstral peak prominence showed dependency on glottal closure. In contrast, vibrational, acoustic, and aerodynamic parameters were found to be highly dependent on the degree of glottal closure: The more complete the glottal closure during phonation, the better the aerodynamic and acoustic characteristics. Hence, complete or at least partial glottal closure appears to enhance acoustic signal quality. Finally, results validate the ex vivo rabbit larynx as an effective model for analyzing the phonatory process.
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Affiliation(s)
- Michael Döllinger
- Division for Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
| | - Stefan Kniesburges
- Division for Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
| | - David A Berry
- Laryngeal Dynamics Laboratory, Division of Head and Neck Surgery, David Geffen School of Medicine at UCLA, 1000 Veteran Avenue, 31-24 Rehab Center, Los Angeles, California 90095-1794, USA
| | - Veronika Birk
- Division for Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
| | - Olaf Wendler
- Laboratory for Molecular Biology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
| | - Stephan Dürr
- Division for Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
| | - Christoph Alexiou
- Section of Experimental Oncology and Nanomedicine (SEON), Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Else Kröner-Fresenius-Stiftung-Professorship, FAU Erlangen-Nürnberg, Glückstrasse 10a, Erlangen, 91054, Germany
| | - Anne Schützenberger
- Division for Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, FAU Erlangen-Nürnberg, Waldstrasse 1, Erlangen, 91054, Germany
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Kime NM, Ryan MJ, Wilson PS. Modelling the production of complex calls in the túngara frog (Physalaemus pustulosus). BIOACOUSTICS 2018. [DOI: 10.1080/09524622.2018.1458249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Nicole M. Kime
- Department of Biological Sciences, Edgewood College, Madison, WI, USA
| | - Michael J. Ryan
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Smithsonian Tropical Research Institute, Balboa Ancon, Republic of Panama
| | - Preston S. Wilson
- Department of Mechanical Engineering, University of Texas at Austin, Austin, TX, USA
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Frey R, Reby D, Fritsch G, Charlton BD. The remarkable vocal anatomy of the koala (Phascolarctos cinereus): insights into low-frequency sound production in a marsupial species. J Anat 2018; 232:575-595. [PMID: 29460389 DOI: 10.1111/joa.12770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2017] [Indexed: 11/27/2022] Open
Abstract
Koalas are characterised by a highly unusual vocal anatomy, with a descended larynx and velar vocal folds, allowing them to produce calls at disproportionately low frequencies. Here we use advanced imaging techniques, histological data, classical macroscopic dissection and behavioural observations to provide the first detailed description and interpretation of male and female koala vocal anatomy. We show that both males and females have an elongated pharynx and soft palate, resulting in a permanently descended larynx. In addition, the hyoid apparatus has a human-like configuration in which paired dorsal, resilient ligaments suspend the hyoid apparatus from the skull, while the ventral parts tightly connect to the descended larynx. We also show that koalas can retract the larynx down into the thoracic inlet, facilitated by a dramatic evolutionary transformation of the ventral neck muscles. First, the usual retractors of the larynx and the hyoid have their origins deep in the thorax. Secondly, three hyoid muscles have lost their connection to the hyoid skeleton. Thirdly, the genioglossus and geniohyoid muscles are greatly increased in length. Finally, the digastric, omohyoid and sternohyoid muscles, connected by a common tendinous intersection, form a guiding channel for the dynamic down-and-up movements of the ventral hyoid parts and the larynx. We suggest that these features evolved to accommodate the low resting position of the larynx and assist in its retraction during call production. We also confirm that the edges of the intra-pharyngeal ostium have specialised to form the novel, extra-laryngeal velar vocal folds, which are much larger than the true intra-laryngeal vocal folds in both sexes, but more developed and specialised for low frequency sound production in males than in females. Our findings illustrate that strong selection pressures on acoustic signalling not only lead to the specialisation of existing vocal organs but can also result in the evolution of novel vocal structures in both sexes.
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Affiliation(s)
- Roland Frey
- Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
| | - David Reby
- School of Psychology, University of Sussex, Brighton, UK
| | - Guido Fritsch
- Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
| | - Benjamin D Charlton
- Behavioural Ecology Research Group, Department of Biology, Anglia Ruskin University, Cambridge, UK
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9
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DUNN JACOBC. Sexual selection and the loss of laryngeal air sacs during the evolution of speech. ANTHROPOL SCI 2018. [DOI: 10.1537/ase.180309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- JACOB C. DUNN
- Behavioural Ecology Research Group, Department of Biology, Anglia Ruskin University, Cambridge
- Division of Biological Anthropology, Department of Archaeology, University of Cambridge, Cambridge
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GARCIA MAXIME, HERBST CHRISTIANT. Excised larynx experimentation: history, current developments, and prospects for bioacoustic research. ANTHROPOL SCI 2018. [DOI: 10.1537/ase.171216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- MAXIME GARCIA
- ENES Lab, Université Lyon/Saint-Etienne, Neuro-PSI, CNRS UMR 9197, Saint-Etienne
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Baotic A, Stoeger AS. Sexual dimorphism in African elephant social rumbles. PLoS One 2017; 12:e0177411. [PMID: 28489908 PMCID: PMC5425207 DOI: 10.1371/journal.pone.0177411] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 04/26/2017] [Indexed: 11/21/2022] Open
Abstract
This study used the source and filter theory approach to analyse sex differences in the acoustic features of African elephant (Loxodonta africana) low-frequency rumbles produced in social contexts ('social rumbles'). Permuted discriminant function analysis revealed that rumbles contain sufficient acoustic information to predict the sex of a vocalizing individual. Features primarily related to the vocalizer's size, i.e. fundamental frequency variables and vocal tract resonant frequencies, differed significantly between the sexes. Yet, controlling for age and size effects, our results indicate that the pronounced sexual size dimorphism in African elephants is partly, but not exclusively, responsible for sexual differences in social rumbles. This provides a scientific foundation for future work investigating the perceptual and functional relevance of specific acoustic characteristics in African elephant vocal sexual communication.
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Affiliation(s)
- Anton Baotic
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, Austria
| | - Angela S. Stoeger
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, Austria
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Ravignani A, Fitch WT, Hanke FD, Heinrich T, Hurgitsch B, Kotz SA, Scharff C, Stoeger AS, de Boer B. What Pinnipeds Have to Say about Human Speech, Music, and the Evolution of Rhythm. Front Neurosci 2016; 10:274. [PMID: 27378843 PMCID: PMC4913109 DOI: 10.3389/fnins.2016.00274] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/31/2016] [Indexed: 12/19/2022] Open
Abstract
Research on the evolution of human speech and music benefits from hypotheses and data generated in a number of disciplines. The purpose of this article is to illustrate the high relevance of pinniped research for the study of speech, musical rhythm, and their origins, bridging and complementing current research on primates and birds. We briefly discuss speech, vocal learning, and rhythm from an evolutionary and comparative perspective. We review the current state of the art on pinniped communication and behavior relevant to the evolution of human speech and music, showing interesting parallels to hypotheses on rhythmic behavior in early hominids. We suggest future research directions in terms of species to test and empirical data needed.
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Affiliation(s)
- Andrea Ravignani
- Artificial Intelligence Lab, Vrije Universiteit BrusselBrussels, Belgium; Sensory and Cognitive Ecology, Institute for Biosciences, University of RostockRostock, Germany
| | - W Tecumseh Fitch
- Department of Cognitive Biology, University of Vienna Vienna, Austria
| | - Frederike D Hanke
- Sensory and Cognitive Ecology, Institute for Biosciences, University of Rostock Rostock, Germany
| | - Tamara Heinrich
- Sensory and Cognitive Ecology, Institute for Biosciences, University of Rostock Rostock, Germany
| | | | - Sonja A Kotz
- Basic and Applied NeuroDynamics Lab, Department of Neuropsychology and Psychopharmacology, Maastricht UniversityMaastricht, Netherlands; Department of Neuropsychology, Max-Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany
| | - Constance Scharff
- Department of Animal Behavior, Institute of Biology, Freie Universität Berlin Berlin, Germany
| | - Angela S Stoeger
- Department of Cognitive Biology, University of Vienna Vienna, Austria
| | - Bart de Boer
- Artificial Intelligence Lab, Vrije Universiteit Brussel Brussels, Belgium
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Efremova KO, Frey R, Volodin IA, Fritsch G, Soldatova NV, Volodina EV. The postnatal ontogeny of the sexually dimorphic vocal apparatus in goitred gazelles (Gazella subgutturosa). J Morphol 2016; 277:826-44. [PMID: 26997608 DOI: 10.1002/jmor.20538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/24/2016] [Accepted: 02/28/2016] [Indexed: 11/11/2022]
Abstract
This study quantitatively documents the progressive development of sexual dimorphism of the vocal organs along the ontogeny of the goitred gazelle (Gazella subgutturosa). The major, male-specific secondary sexual features, of vocal anatomy in goitred gazelle are an enlarged larynx and a marked laryngeal descent. These features appear to have evolved by sexual selection and may serve as a model for similar events in male humans. Sexual dimorphism of larynx size and larynx position in adult goitred gazelles is more pronounced than in humans, whereas the vocal anatomy of neonate goitred gazelles does not differ between sexes. This study examines the vocal anatomy of 19 (11 male, 8 female) goitred gazelle specimens across three age-classes, that is, neonates, subadults and mature adults. The postnatal ontogenetic development of the vocal organs up to their respective end states takes considerably longer in males than in females. Both sexes share the same features of vocal morphology but differences emerge in the course of ontogeny, ultimately resulting in the pronounced sexual dimorphism of the vocal apparatus in adults. The main differences comprise larynx size, vocal fold length, vocal tract length, and mobility of the larynx. The resilience of the thyrohyoid ligament and the pharynx, including the soft palate, and the length changes during contraction and relaxation of the extrinsic laryngeal muscles play a decisive role in the mobility of the larynx in both sexes but to substantially different degrees in adult females and males. Goitred gazelles are born with an undescended larynx and, therefore, larynx descent has to develop in the course of ontogeny. This might result from a trade-off between natural selection and sexual selection requiring a temporal separation of different laryngeal functions at birth and shortly after from those later in life. J. Morphol. 277:826-844, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kseniya O Efremova
- Department of General Biology, Medicobiological Faculty, Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | - Roland Frey
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
| | - Ilya A Volodin
- Department of Vertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.,Scientific Research Department, Moscow Zoo, Moscow, Russia
| | - Guido Fritsch
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
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Universal mechanisms of sound production and control in birds and mammals. Nat Commun 2015; 6:8978. [PMID: 26612008 PMCID: PMC4674827 DOI: 10.1038/ncomms9978] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 10/22/2015] [Indexed: 11/08/2022] Open
Abstract
As animals vocalize, their vocal organ transforms motor commands into vocalizations for social communication. In birds, the physical mechanisms by which vocalizations are produced and controlled remain unresolved because of the extreme difficulty in obtaining in vivo measurements. Here, we introduce an ex vivo preparation of the avian vocal organ that allows simultaneous high-speed imaging, muscle stimulation and kinematic and acoustic analyses to reveal the mechanisms of vocal production in birds across a wide range of taxa. Remarkably, we show that all species tested employ the myoelastic-aerodynamic (MEAD) mechanism, the same mechanism used to produce human speech. Furthermore, we show substantial redundancy in the control of key vocal parameters ex vivo, suggesting that in vivo vocalizations may also not be specified by unique motor commands. We propose that such motor redundancy can aid vocal learning and is common to MEAD sound production across birds and mammals, including humans.
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Stoeger AS, Manger P. Vocal learning in elephants: neural bases and adaptive context. Curr Opin Neurobiol 2014; 28:101-7. [PMID: 25062469 PMCID: PMC4181794 DOI: 10.1016/j.conb.2014.07.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 06/28/2014] [Accepted: 07/01/2014] [Indexed: 10/28/2022]
Abstract
In the last decade clear evidence has accumulated that elephants are capable of vocal production learning. Examples of vocal imitation are documented in African (Loxodonta africana) and Asian (Elephas maximus) elephants, but little is known about the function of vocal learning within the natural communication systems of either species. We are also just starting to identify the neural basis of elephant vocalizations. The African elephant diencephalon and brainstem possess specializations related to aspects of neural information processing in the motor system (affecting the timing and learning of trunk movements) and the auditory and vocalization system. Comparative interdisciplinary (from behavioral to neuroanatomical) studies are strongly warranted to increase our understanding of both vocal learning and vocal behavior in elephants.
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Affiliation(s)
- Angela S Stoeger
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
| | - Paul Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Stead N. THE SAME BUT DIFFERENT: HUMAN-LIKE ELEPHANT CALLS. J Exp Biol 2013. [DOI: 10.1242/jeb.096016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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