with age [1,2]. Blocks occur unexpectedly, even for AWS themselves, and can also halt normal inspiration and expiration. This symptom resembles the chief complaints ("voice not coming out" and "clogged voice") made by patients with muscle tension dysphonia (MTD) and adductor spasmodic dysphonia (AdSD). A systematic review of voice therapy in MTD showed that there were positive changes to outcome measures immediately following a period of therapy [3], and that therapy for MTD continued to be effective for 6 months after the completion of therapy [4]. However, speech therapy for adults who stutter (AWS) is limited [5]. Stuttering is readily modified during treatment in the clinic, but this gain is difficult to transfer outside of the clinic; when it does transfer, the effect does not last long [6].There have been many empirical studies, as well as theoretical descriptions, of the role of larynx during stuttering [7,8]. However, more objective information regarding the nature of laryngeal behavior during actual instances of stuttering is needed. The two general aspects of laryngeal activity for speech include phonation vibration [9] and abductory-adductory adjustment of the glottal aperture for voicing distinctions [10]. The latter adjustments are more likely to be related to the physiological disruptions associated with stuttering. MTD is a condition characterized by increased tension in the (para-) laryngeal muscles [11], often involving glottis closure. Very few studies have examined vocal fold moAbstract Background: Stuttering is a speech disorder; the primary symptom in adults who stutter (AWS) is blocks, which halt both speech and breathing. This study aimed to evaluate vocal fold motion during blocks in AWS, in order to better understand this condition.