Songbirds tune their vocal tract to the fundamental frequency of their song
04 Apr 2006-Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences)-Vol. 103, Iss: 14, pp 5543-5548
TL;DR: Through x-ray cinematography of singing birds, it is shown that birdsong is accompanied by cyclical movements of the hyoid skeleton and changes in the diameter of the cranial end of the esophagus that maintain an inverse relationship between the volume of the oropharyngeal cavity and esophagi and the song's fundamental frequency.
Abstract: In human speech, the sound generated by the larynx is modified by articulatory movements of the upper vocal tract, which acts as a variable resonant filter concentrating energy near particular frequencies, or formants, essential in speech recognition. Despite its potential importance in vocal communication, little is known about the presence of tunable vocal tract filters in other vertebrates. The tonal quality of much birdsong, in which upper harmonics have relatively little energy, depends on filtering of the vocal source, but the nature of this filter is controversial. Current hypotheses treat the songbird vocal tract as a rigid tube with a resonance that is modulated by the end-correction of a variable beak opening. Through x-ray cinematography of singing birds, we show that birdsong is accompanied by cyclical movements of the hyoid skeleton and changes in the diameter of the cranial end of the esophagus that maintain an inverse relationship between the volume of the oropharyngeal cavity and esophagus and the song’s fundamental frequency. A computational acoustic model indicates that this song-related motor pattern tunes the major resonance of the oropharyngeal–esophageal cavity to actively track the song’s fundamental frequency.
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TL;DR: The hypothesis that females choose mates by the evaluation of male motor performance is reviewed, and it is proposed that ornaments often arise secondarily as a way to enhance the apparent skill or vigour ofmale motor performance.
386 citations
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...Studies of vocal mechanics during the last 25 years have illustrated that song production by male birds is intrinsically challenging, involving the simultaneous control and coordination of breathing, syrinx modulations (the left and right sides having separate innervations) and vocal tract modulations including those of the trachea, mandible and oropharyngeal cavity (Nowicki 1987; Podos & Nowicki 2004; Suthers 2004; Riede et al. 2006)....
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...…the simultaneous control and coordination of breathing, syrinx modulations (the left and right sides having separate innervations) and vocal tract modulations including those of the trachea, mandible and oropharyngeal cavity (Nowicki 1987; Podos & Nowicki 2004; Suthers 2004; Riede et al. 2006)....
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TL;DR: The chapter focuses on the evolution of song dialects and emphasizes the functional hypotheses to explain their evolution, and describes the scenarios by which songs may diverge indirectly through selection on components of the vocal apparatus such as body size and beak form and function.
Abstract: Publisher Summary This chapter outlines the evolution of geographic variation in birdsong. Studies of vocal signals in birds offer potentially useful opportunities for empirical tests of the relationships among geographic signal divergence, reproductive isolation, and speciation. The goal of the chapter is to evaluate, from both empirical and conceptual perspectives, the factors that facilitate the evolution of geographic variation in bird vocalizations. The chapter focuses on the evolution of song dialects and emphasizes the functional hypotheses to explain their evolution. An alternative set of hypotheses suggests that the song features may diverge through by‐product scenarios, in which selection for non-recognition functions drives incidental changes in song structure, and geographic variation. The chapter also describes the scenarios by which songs may diverge indirectly through selection on components of the vocal apparatus such as body size and beak form and function.
303 citations
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...Components of the vocal tract, including the trachea, larynx, and beak, modify the spectral structure of song, and in particular serve to dampen harmonic overtones and thus enable the production of pure‐tonal songs (Beckers et al., 2003; Hoese et al., 2000; Nowicki and Marler, 1988; Riede et al., 2006; Westneat et al., 1993)....
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TL;DR: The dating of the FOXP2 gene, which governs the embryonic development of subcortical structures regulating motor control, including speech production, as well as cognitive processes including syntax provides an insight on the evolution of speech and language.
Abstract: Human speech involves species‐specific anatomy deriving from the descent of the tongue into the pharynx. The human tongue’s shape and position yields the 1:1 oral‐to‐pharyngeal proportions of the supralaryngeal vocal tract. Speech also requires a brain that can “reiterate”—freely reorder a finite set of motor gestures to form a potentially infinite number of words and sentences. The end points of the evolutionary process are clear. The chimpanzee lacks a supralaryngeal vocal tract capable of producing the “quantal” sounds which facilitate both speech production and perception and a brain that can reiterate the phonetic contrasts apparent in its fixed vocalizations. The traditional Broca‐Wernicke brain‐language theory is incorrect; neural circuits linking regions of the cortex with the basal ganglia and other subcortical structures regulate motor control, including speech production, as well as cognitive processes including syntax. The dating of the FOXP2 gene, which governs the embryonic development of th...
256 citations
TL;DR: The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA.
Abstract: Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1-4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species.
207 citations
TL;DR: Birdsong provides neuroscientists with a uniquely powerful model for studying imitative vocal learning in a system where the brain structures responsible for song learning and production are well known, and crystallized adult song is likely to provide insights into the neural control of facultative behavior.
Abstract: Birdsong provides neuroscientists with a uniquely powerful model for studying imitative vocal learning in a system where the brain structures responsible for song learning and production are well known. The 4,500+ species of songbirds provide a remarkable diversity of songs with a variety of tonal, structural, and learning characteristics, but most studies of the neural bases of learning have concentrated on two domesticated species, the canary and the zebra finch. Important differences in the songs of these two species provide useful properties for comparative studies, which could be expanded by using other species that demonstrate mimicry or action-based learning. Although the primary goal of most studies of the neural bases of song has been to define the mechanisms responsible for imitative learning during development, studies of adult crystallized song are important for two reasons. First, they define the endpoint of learning, and second, adult song shows interesting forms of variability in its performance. The degree of adult song variability itself varies among individuals and is influenced by the sources from which the song was learned, how the song was assembled during learning, behavioral responses of adult listeners, and levels of circulating sex steroids. In addition, song may be associated with coordinated visual displays, which also contribute to its communicative function. Thus the study of crystallized adult song is likely to provide insights into the neural control of facultative behavior as well as into the important question of how imitative learning takes place.
194 citations
Cites background from "Songbirds tune their vocal tract to..."
...In a similar fashion, throat movements that reflect changes in the volume of the upper respiratory tract that track changes in syllable frequency (Riede et al., 2006) can be visually emphasized by the “flashing” of contrasting throat feathers....
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References
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Book•
01 Jan 1971
TL;DR: A second edition was begun in 1970, the aim was to retain the original format, but to expand the content, especially in the areas of digital communications and com puter techniques for speech signal processing.
Abstract: The first edition of this book has enjoyed a gratifying existence. 1s sued in 1965, it found its intended place as a research reference and as a graduate-Ievel text. Research laboratories and universities reported broad use. Published reviews-some twenty-five in number-were universally kind. Subsequently the book was translated and published in Russian (Svyaz; Moscow, 1968) and Spanish (Gredos, S.A.; Madrid, 1972). Copies of the first edition have been exhausted for several years, but demand for the material continues. At the behest of the publisher, and with the encouragement of numerous colleagues, a second edition was begun in 1970. The aim was to retain the original format, but to expand the content, especially in the areas of digital communications and com puter techniques for speech signal processing. As before, the intended audience is the graduate-Ievel engineer and physicist, but the psycho physicist, phonetician, speech scientist and linguist should find material of interest."
1,386 citations
TL;DR: Not only does the songbird's vocal tract act as an acoustic filter, but its filter characteristics are actively coordinated with the output of the syrinx, suggesting that birdsong and human phonation are more analogous than previously thought.
Abstract: The complexity and dependence on learning of many bird sounds have suggested parallels between birdsong and human speech1–4, but the mechanisms by which each is produced have been supposed to differ markedly. In human speech, resonances of the vocal tract are thought to modulate in complex ways the sound produced by vibration of the vocal folds5–7. The current theory of birdsong production holds that all variation in sound quality arises from the primary sound-producing organ, the syrinx, and that resonances of the vocal tract play no part8,9. Here I present evidence, obtained from acoustic analyses of birdsongs recorded in a helium atmosphere, which contradicts this hypothesis. Not only does the songbird's vocal tract act as an acoustic filter, but its filter characteristics are actively coordinated with the output of the syrinx. Songbird and human phonation are thus more analogous than previously thought, in that both require coordination of an array of diverse motor systems.
248 citations
TL;DR: It is found that the acoustic frequencies of notes in a song have a consistent, positive correlation with beak gape in both species and cranial kinematics, particularly beak movements, influence the resonance properties of the vocal tract by varying its physical dimensions and thus play an active role in the production of birdsong.
Abstract: The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza georgiana). These birds are closely related emberizine sparrows, but their songs differ radically in frequency and amplitude structure. We found that the acoustic frequencies of notes in a song have a consistent, positive correlation with beak gape in both species. Beak gape increased significantly with increasing frequency during the first two notes in Z. albicollis song, with a mean frequency for note 1 of 3 kHz corresponding to a gape of 0.4 cm (a 15 degrees gape angle) and a mean frequency for note 2 of 4 kHz corresponding to a gape of 0.7 cm (a 30 degrees gape angle). The relationship between gape and frequency for the upswept third note in Z. albicollis also was significant. In M. georgiana, low frequencies of 3 kHz corresponding to beak gapes of 0.2-0.3 cm (a 10-15 degrees break angle), whereas frequencies of 7-8 kHz were associated with flaring of the beak to over 1 cm (a beak angle greater than 50 degrees). Beak gape and song amplitude are poorly correlated in both species. We conclude that cranial kinematics, particularly beak movements, influence the resonance properties of the vocal tract by varying its physical dimensions and thus play an active role in the production of birdsong.
184 citations