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S/Z Ratio

The S/Z Ratio is an indicator of voice disorder. It measures the ability to sustain the voiceless sound ‘s’ in comparison to sustaining the voiced sound ‘z’. 95% of people who have some difficulty affecting the movement of their vocal cords have an S/Z ratio of greater than 1.40. This article demonstrates how to calculate an S/Z Ratio and how to interpret the result.

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Reflux

What is reflux? The escape of acid and other digestive fluids from the stomach into the esophagus (the tube connecting the stomach to the throat) and up into the larynx (voice box). What causes it? When normal, healthy individuals eat or drink, swallowing propels food and…

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Laryngeal Papillomas

What are they? Papillomas are benign growths. They do not become malignant. They occur mainly on the vocal folds but they can also appear in the larynx. They can occur as a single papilloma or in clusters like warts. In the same way that warts are caused by a virus,…

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Objective Measurement of Voice

Whilst instrumental measurement of voice promises to provide an objective measure of relevant parameters, there are many elements that influence comparison of results obtained on different occasions. Reactivity, human interpretation, the control of extraneous variables and the lack of normative data are all influencing factors.

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Acoustic Measures (Norms)

Question: I am really impressed with your site, but was wondering if you had any good references to obtain normative comparison for things such as jitter, shimmer, noise to harmonic ratio, and fundamental frequency. My Reply: It is difficult…

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Laryngoscopic Examination

Examination of the larynx (laryngoscopic examination) and vocal tract is essential for anyone presenting with a persistent voice disorder, in order to rule out or identify any laryngeal pathology. There are four main methods: mirror laryngoscopy, rigid endoscopy, flexible nasendoscopy and direct laryngoscopy. A stroboscope is frequently used to improve views of the vibrating vocal folds (vocal cords). Children generally tolerate these procedures.

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Instrumental Measurement of Voice

Instrumental measurement of voice attempts to make objective, quantifiable measurements of vocal characteristics and examine the physiology of phonation. Acoustic analysis is commonly carried out by speech therapists. The Praat software program assists with the analysis, synthesis, and manipulation of speech. This article discusses a brief protocol for performing acoustic analysis.

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Perceptual Assessment of Voice

Perceptual assessment of voice involves describing the voice solely by listening. Voice assessment may be informal or formal. Formal perceptual evaluation typically uses a published protocol to systematically describe characteristics of voice disorder. This article outlines a screening assessment known as CVE2, demonstrating how to build a vocal profile.

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