Date of Degree
MA (Master of Arts)
Speech Pathology and Audiology
Eileen M. Finnegan
Contrary to the previous belief that any presence of supraglottic activity indicates presence of hyperfunctional vocal pathology, Stager et al. (2000, 2002) found out that supraglottic compressions do occur in normal subjects. In fact, dynamic false vocal fold compressions during production of phrases with a great number of glottal stops were noted. The present study hypothesized that a similar pattern s would be observed at sentence level, where at least 50% or higher incidence of dynamic FVF compressions would be observed at aurally perceived glottal stops and other linguistic markers, such as vowel-initial words, /t/ final words, punctuations and phrase boundaries, where glottal stops were likely to occur.
Nasendoscopic recordings were obtained from 8 healthy subjects (2M; 6F) during production of selected sentence stimuli.. Their audio recordings were rated by two judges to detect the location of glottal stops. Then, the video images were analyzed to categorize the presence and absence of dynamic and static false vocal folds (FVF) or anterior posterior (AP) compressions. Results indicated that the incidence of dynamic FVF compressions was 30%. Nevertheless, the average incidence was elevated at aurally perceived glottal stops and at the linguistic contexts that are known to be associated with glottal stops compared to other contexts.
The false vocal folds (FVF), which are situated above our true vocal folds within the larynx or “voice box,” come together during swallowing or coughing to protect the airway. At one time, FVF compression while voicing was considered as signs of hyperfunctional voice disorders or maladaptive compensations to vocal fold paralysis. However, Stager et al. (2000, 2002) found frequent brief compressions of the FVF during production of glottal stops (specifically, vowel initiated words) by normal subjects when they recited short phrases. Glottal stops are brief audible cessation of airflow, which can often be heard during phrases such as “We eat eels every Easter.”
The present study was designed to further investigate the relationship between FVF compressions and glottal stops and specific linguistic contexts where glottal stops have been known to occur. Eight healthy subjects were recruited. Video images of true and false vocal folds movement and the audio recordings were collected via flexible nasendoscope while they read a set of longer, complex sentences. The incidence of brief or dynamic FVF compressions at aurally perceived glottal stops were only 30%, which was lower than Stager et al.’s results. Nevertheless, elevated frequencies of FVF compressions were noted at words ending with vowels or ending with “T” which were known to be associated with an increased number of glottal stops. This study further elucidated the pattern of normal FVF compressions at certain linguistic contexts. This result will further assist in differentiating normal FVF activity patterns from abnormal patterns and in accurate diagnosis of hyperfunctional voice disorder in clinic settings.
vi, 35 pages
Includes bibliographical references (pages 34-35).
Copyright 2015 Se In (Se-in) Kim