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Vocal Characteristics (vocal + characteristic)

Distribution by Scientific Domains

Life Sciences	80%

Selected Abstracts

Macrogeographical variability in the great call of Hylobates agilis: assessing the applicability of vocal analysis in studies of fine-scale taxonomy of gibbons

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2010
R. Heller
Abstract Vocal characteristics have been used extensively to distinguish different taxonomic units of gibbons (family Hylobatidae). The agile gibbon (Hylobates agilis) has a disjunct distribution range in the Southeast Asian archipelago (remnants of the former Sunda landmass), and populations on different islands are currently recognized as distinct subspecies or even species. We recorded great calls from female agile gibbons from two populations on Sumatra and two populations on Borneo and examined the vocal variability on four levels: within-individuals, between-individuals, between-populations and between-islands. The primary objective was to evaluate the effect of geographical isolation on variability in song pattern and to test whether proposed island-specific song characteristics exist, reflecting evolutionary divergence between Sumatran and Bornean agile gibbons. One hundred great calls were recorded from 20 females and analyzed for 18 spectral and temporal acoustic parameters. Principal component analysis followed by a nested ANOVA on components revealed a complex pattern of song variability not likely to reflect taxonomic or evolutionary relationship. We found no evidence that Sumatran and Bornean agile gibbons have evolved different vocal characteristics, refuting a distinction between them based on vocal characteristics. A high level of plasticity was found in great calls from the same individual, and generally the inferred pattern of variability suggested that ecological or social factors may confound any genetically based island dialects. Am. J. Primatol. 72:142,151, 2010. © 2009 Wiley-Liss, Inc. [source]

Duet-splitting and the evolution of gibbon songs

BIOLOGICAL REVIEWS, Issue 1 2002
THOMAS GEISSMANN
ABSTRACT Unlike the great apes and most other primates, all species of gibbons are known to produce elaborate, species-specific and sex-specific patterns of vocalisation usually referred to as ,'songs". In most, but not all, species, mated pairs may characteristically combine their songs in a relatively rigid pattern to produce coordinated duet songs. Previous studies disagree on whether duetting or the absence of duetting represented the primitive condition in gibbons. The present study compares singing behaviour in all gibbon species. Various vocal characteristics were subjected to a phylogenetic analysis using previously published phylogenetic trees of the gibbon radiation as a framework. Variables included the degree of sex-specificity of the vocal repertoire, the occurrence of solo songs, and the preference for a specific time of day for song-production. The results suggest the following scenario for the evolution of gibbon songs: (1) The last common ancestor of recent gibbons produced duet songs. (2) Gibbon duets probably evolved from a song which was common to both sexes and which only later became separated into male-specific and female-specific parts (song-splitting theory). (3) A process tentatively called "duet-splitting" is suggested to have led secondarily from a duetting species to a non-duetting species, in that the contributions of the pair-partners split into temporally segregated solo songs. This appears to be the first time that a non-duetting animal can be shown to be derived from a duetting form. (4) The return to exclusive solo singing may be related to the isolated island distribution of the non-duetting species. [source]

Oral myofunctional and vocal characteristics in subjects subjected to oral rehabilitation with osseointegrated implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2006
Karilla Matteo Sansone
Abstract Purpose: The aim of this study was to evaluate the effect of oral rehabilitation using immediately loaded fixed implant-supported mandibular prostheses, considering chewing, swallowing, speech and voice aspects. Material and methods: Fourteen patients subjected to this treatment were evaluated by a clinical examination of the stomatognathic system and perceptual evaluation of voice quality before oral rehabilitation, as well as after 1 and 4 months. Results: After oral rehabilitation, the results showed that there were no significant modifications in the aspects investigated. Conclusion: Thus, implant-supported prosthetic rehabilitation, despite providing a more satisfactory occlusal standard, did not yield changes in the functional patterns of individuals in this study. [source]