Effects of Volume, Pitch, and Phonation Type on Oscillation Initiation and Termination Phases Investigated With High-speed Videoendoscopy

Vowel onset measures and their reliability, sensitivity and specificity: A systematic literature review

OBJECTIVE

To systematically evaluate the evidence for the reliability, sensitivity and specificity of existing measures of vowel-initial voice onset.

METHODS

A literature search was conducted across electronic databases for published studies (MEDLINE, EMBASE, Scopus, Web of Science, CINAHL, PubMed Central, IEEE Xplore) and grey literature (ProQuest for unpublished dissertations) measuring vowel onset. Eligibility criteria included research of any study design type or context focused on measuring human voice onset on an initial vowel. Two independent reviewers were involved at each stage of title and abstract screening, data extraction and analysis. Data extracted included measures used, their reliability, sensitivity and specificity. Risk of bias and certainty of evidence was assessed using GRADE as the data of interest was extracted.

RESULTS

The search retrieved 6,983 records. Titles and abstracts were screened against the inclusion criteria by two independent reviewers, with a third reviewer responsible for conflict resolution. Thirty-five papers were included in the review, which identified five categories of voice onset measurement: auditory perceptual, acoustic, aerodynamic, physiological and visual imaging. Reliability was explored in 14 papers with varied reliability ratings, while sensitivity was rarely assessed, and no assessment of specificity was conducted across any of the included records. Certainty of evidence ranged from very low to moderate with high variability in methodology and voice onset measures used.

CONCLUSIONS

A range of vowel-initial voice onset measurements have been applied throughout the literature, however, there is a lack of evidence regarding their sensitivity, specificity and reliability in the detection and discrimination of voice onset types. Heterogeneity in study populations and methods used preclude conclusions on the most valid measures. There is a clear need for standardisation of research methodology, and for future studies to examine the practicality of these measures in research and clinical settings.

Vocal Release Time of Mandarin Vowels at Different Pitch Levels

OBJECTIVE

To explore how vocal release time (VRT) varies when young adults articulate the three Chinese vertex vowels with increasingly higher pitch levels.

STUDY DESIGN

Sound pressure (SP) and electroglottographic (EGG) signals were recorded synchronously from 53 males and 53 females saying sustained /A/, /i/, /u/ at five equally spaced pitch heights, each being higher than the one before.

METHODS

About 3030 effective ST (semitone) and VRT measures were obtained. Statistical analyses of them were done by using SPSS 13.0 and Excel 2010.

FINDINGS

As mean STs increase linearly from pitch levels one to five, mean VRTs display a rise-fall pattern in a big group of subjects, but a fall-rise pattern in a small group of them. In both cases, pitch and VRT tend to present a curvilinear relationship, although VRT varies in opposite directions. And also, high vowels tend to have larger VRT than low vowels.