Using nasovideofibroscopic data to observe abnormal laryngeal behavior in stutterers : A case study

The aim of this presentation is to give some characteristics about the laryngeal behavior of stuttering speakers by using nasofibroscopic data. Indeed, if it is well-known that the laryngeal activity is abnormal during stutterers' disfluences, only few studies had been carried out using such type of data, despite the fact that it allows direct observation of laryngeal movements. 1 stutterer and 1 control subject were recruited for this research which had been led at the Georges Pompidou Hospital (Paris). A flexible probe, linked to a Kay Pentax (RlS 9100 model) device, had been introduced through the nose of each patient in order to observe the larynx. At the same time, speech had been recorded using by a microphone linked to the same device. Each subject had to carry out the following tasks: production of [i] and [a] vowels, silent reading, reading with a delayed auditory feedback (DAF), reading without DAF, spontaneous speech without DAF, spontaneous speech when stutterer uses different strategies to avoid stuttering (ERASM,...). Movies obtained have been analyzed with the software Sound Forge 10.0a in order to study images synchronized with sound. Nasofibroscopic data reveal the presence of spasms during disfluences. More precisely, a narrowing of pharyngeal-laryngeal cavity is generally observed accompanied by several opening/closure movements of the arytenoids. Strong contacts of the arytenoids, trembling of the tongue root, up and down movements of the larynx have been noticed during disfluences. Gestures are were more fluent when the stutterer uses ERASM or speaks with DAF. No triple plicature closure was observed during disfluences, contradicting the Valsalva hypothesis (Monfrais-Pfauwadel, 2005)