Comparing Chalk With Cheese—The EGG Contact Quotient Is Only a Limited Surrogate of the Closed Quotient.
Summary The electroglottographic (EGG) contact quotient (CQegg), an estimate of the relative duration of vocal fold contact per vibratory cycle, is the most commonly used quantitative analysis parameter in EGG. The purpose of this study is to quantify the CQegg's relation to the closed quotient, a m...
| Publicado en: | Journal of Voice Vol. 31; no. 4; pp. 401 - 410 |
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| Autores principales: | , , , |
| Formato: | research Journal Article |
| Publicado: |
Elsevier B.V.
Jul2017
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=123974921&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 123974921 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 08921997 H24 jtl: Journal of Voice issn: 08921997 maglogo: N pubinfo: dt: Jul2017 vid: 31 iid: 4 pid: 467 pub: Elsevier B.V. place: New York, New York artinfo: ui: 123974921 123974921 123974921 10.1016/j.jvoice.2016.11.007 123974921 ppf: 401 ppct: 9 formats: tig: atl: Comparing Chalk With Cheese—The EGG Contact Quotient Is Only a Limited Surrogate of the Closed Quotient. aug: au: Herbst, Christian T. Schutte, Harm K. Bowling, Daniel L. Svec, Jan G. affil: Bioacoustics Laboratory, Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria sug: subj: Vocal Cords Vibration Singing Human Male Female Phonation Evaluation Electrophysiology Methods Male Female ab: Summary The electroglottographic (EGG) contact quotient (CQegg), an estimate of the relative duration of vocal fold contact per vibratory cycle, is the most commonly used quantitative analysis parameter in EGG. The purpose of this study is to quantify the CQegg's relation to the closed quotient, a measure more directly related to glottal width changes during vocal fold vibration and the respective sound generation events. Thirteen singers (six females) phonated in four extreme phonation types while independently varying the degree of breathiness and vocal register. EGG recordings were complemented by simultaneous videokymographic (VKG) endoscopy, which allows for calculation of the VKG closed quotient (CQvkg). The CQegg was computed with five different algorithms, all used in previous research. All CQegg algorithms produced CQegg values that clearly differed from the respective CQvkg, with standard deviations around 20% of cycle duration. The difference between CQvkg and CQegg was generally greater for phonations with lower CQvkg. The largest differences were found for low-quality EGG signals with a signal-to-noise ratio below 10 dB, typically stemming from phonations with incomplete glottal closure. Disregarding those low-quality signals, we found the best match between CQegg and CQvkg for a CQegg algorithm operating on the first derivative of the EGG signal. These results show that the terms “closed quotient” and “contact quotient” should not be used interchangeably. They relate to different physiological phenomena. Phonations with incomplete glottal closure having an EGG signal-to-noise ratio below 10 dB are not suited for CQegg analysis. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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