| Title: |
Spatio-temporal analysis of irregular vocal fold oscillations: Biphonation due to desynchronization of spatial modes |
| Authors: |
Jürgen Neubauer; Patrick Mergell; Ulrich Eysholdt; Hanspeter Herzel; Typeset Revtex |
| Contributors: |
The Pennsylvania State University CiteSeerX Archives |
| Source: |
http://itb.biologie.hu-berlin.de/~neubauer/publications/ap-moden.pdf. |
| Collection: |
CiteSeerX |
| Description: |
We report on direct observation and modal analysis of irregular spatio-temporal vibration patterns of vocal fold pathologies in vivo. We describe the observed oscillation patterns quantitatively with multi-line kymograms, spectral analysis, and spatio-temporal plots. We decompose the complex spatio-temporal vibration pattern by empirical orthogonal functions into independent vibratory modes, show quantitatively that biphonation can be induced either by left-right asymmetry or by desynchronized anterior-posterior vibratory modes, and introduce the term 'AP (anteriorposterior) biphonation'. The presented phonation examples show that for normal phonation the first two modes su#ciently explain the glottal dynamics. The spatio-temporal oscillation pattern associated with biphonation due to left-right asymmetry can be explained by the first three modes. Higher order modes are required to describe the pattern for biphonation induced by anteriorposterior vibrations. We quantify spatial irregularity by an entropy measure, that is significantly higher for irregular phonation than for normal phonation. We introduce two asymmetry measures, the left-right asymmetry and the anterior-posterior asymmetry, as the ratios of the fundamental frequencies of left and right vocal fold and of anterior-posterior modes, respectively. These quantities clearly di#erentiate between left-right biphonation and anterior-posterior biphonation. This paper proposes methods to analyze quantitatively irregular vocal fold contour patterns in vivo and complements previous findings of desynchronization of vibration modes in computer models and in in vitro experiments. |
| Document Type: |
text |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.25.1485 |
| Availability: |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.25.1485; http://itb.biologie.hu-berlin.de/~neubauer/publications/ap-moden.pdf |
| Rights: |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| Accession Number: |
edsbas.EEDBE254 |
| Database: |
BASE |