How parrots talk: insights based on CT scans, image processing, and mathematical models

  title={How parrots talk: insights based on CT scans, image processing, and mathematical models},
  author={D. Patterson and I. Pepperberg and B. Story and E. Hoffman},
  booktitle={Medical Imaging},
Little is known about mechanisms of speech production in parrots. Recently, however, techniques for correlating vocal tract shape with vowel production in humans have become more sophisticated and we have adapted these techniques for use with parrots. We scanned two grey parrot heads with intact vocal tracts. One specimen, 'Oldbird' was fixed with its beak propped open; the second 'Youngbird' was fixed with its beak closed. Using VIDA software, we (1) established that differences in tongue and… Expand
Measurement of grey parrot (Psittacus erithacus) trachea via magnetic resonance imaging, dissection, and electron beam computed tomography
Comparing results for tracheal measurements provided by magnetic resonance imaging of a live bird, caliper measurements of four preserved specimens, and electron beam computed tomography of three of these preserved specimens suggests how noninvasive techniques can be used for cross‐species comparisons, including the coevolution of structure and function in avian mimicry. Expand
Vocal tract articulation revisited: the case of the monk parakeet
X-ray cinematographic imaging of naturally vocalizing monk parakeets was used to assess which articulators are possibly involved in vocal tract filtering in this species, and strong positive correlations between beak opening and amplitude as well as changes in tongue height and amplitude in several types of vocalization were found. Expand
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The Avian Lingual and Laryngeal Apparatus Within the Context of the Head and Jaw Apparatus, with Comparisons to the Mammalian Condition: Functional Morphology and Biomechanics of Evaporative Cooling, Feeding, Drinking, and Vocalization
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Bill opening and sound spectrum in barnacle goose loud calls: individuals with ‘wide mouths’ have higher pitched voices
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Comparisons of formant locations extracted from the natural (recorded) speech of theImaged subject and from simulations using the newly acquired area functions show reasonable similarity but suggest that the imaged vocal tract shapes may be somewhat centralized. Expand
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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. Expand
Vocal tract resonances in oscine bird sound production: evidence from birdsongs in a helium atmosphere
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. Expand
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How are different sounds made? If we could see sound, it would look like waves. The length, speed, and direction of each wave determine what kind of sound we hear. Height is also a factor. Each waveExpand
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