Impact of ‘Be Clear’ Treatment on Speech and Functional Communication Outcomes in Adults with Post-Stroke Dysarthria

Background: Dysarthria is a neurogenic speech disorder characterized by dysprosody and distinguished by deficits in speech understandability. Clear speech is a compensatory treatment approach that has gained traction in recent years. Studies investigating the impact of ‘Be Clear’ treatment are limited, particularly in post-stroke dysarthria. Objectives: The study aimed to investigate the effect of ‘Be clear’ speech treatment on speech intelligibility, speech naturalness, prosodic characteristics, and communication participation in adults with post-stroke dysarthria. Methods: Eight Kannada-speaking participants aged between 30 to 66 years with post-stroke dysarthria were recruited for the study. ‘Be clear’ treatment was practiced over the duration of sixteen one-hour sessions across four weeks. Assessments of narrative intelligibility, overall speech naturalness, and functional communication were carried out. Acoustic measures included measurements of mean fundamental frequency, standard deviation of fundamental frequency, mean intensity, and standard deviation of intensity. Results: Participants demonstrated significant improvements in narrative intelligibility, and overall speech naturalness, between pre- versus post and pre-versus follow-up (FUP) conditions. In acoustic variables, significant changes were observed in mean intensity between pre-post and pre-FUP conditions. Speech handicap was reduced and improvements in overall communication partner ratings were noticed following the treatment. Conclusions: 'Be clear' treatment led to improvements in narrative intelligibility, enhanced speech naturalness, reduced speech handicap, increased communication participation, and increased vocal intensity in the participants. Future studies could incorporate a broader range of parameters with a larger sample size. Key words: Post-stroke dysarthria, ‘Be clear’, speech intelligibility and naturalness, fundamental frequency and intensity