Author ORCID Identifier

https://orcid.org/0009-0000-2168-4585

Semester

Spring

Date of Graduation

2025

Document Type

Thesis

Degree Type

MS

College

School of Medicine

Department

Communication Sciences and Disorders

Committee Chair

Anna Coy

Committee Co-Chair

Megan Israelsen-Augenstein

Committee Member

Megan Israelsen-Augenstein

Committee Member

Kimberly Meigh

Abstract

ABSTRACT

Clear Speech Intervention in Parkinson’s Disease: A Single Case Design Examining Acoustic and Aerodynamic Outcomes Following a Structured Protocol

Zachariah Backus

Purpose:

Parkinson Disease (PD) is a neuro-progressive movement disorder that impacts all movement of the body, including speech production. Ninety percent of individuals living with PD will experience hypokinetic dysarthria, a motor speech disorder, during the progression of their disease. Clear speech instruction is a treatment strategy used to increase motor speech outcomes in those with PD. Studies have shown positive changes in articulation, prosody, voice, and listener perception measures in those with PD after clear speech instruction in a single session. While clear speech instruction in a single session has been examined in the current literature, there is limited research that has explored a structured, multi-phase intervention that incorporates clear speech instructions and the principles of motor learning. Therefore, the purpose of this study was to examine changes in aerodynamic and acoustic voice measures in a client with PD following a structured Clear Speech Intervention.

Method:

“Betty”, a 98-year-old female with a medical diagnosis of PD participated in Clear Speech Intervention. Clear Speech Intervention is a nine-week intervention that utilizes clear speech instructions and the principles of motor learning. Betty had slight-mild hypokinetic dysarthria due to her PD, which impacted her articulation and prosody. She attended baseline, treatment, and follow-up sessions for a total of fourteen weeks. At every session, acoustic and aerodynamic data were collected. Acoustic measures extracted included mean pitch, duration, local jitter and shimmer, and CPPS. Aerodynamic measures extracted included peak expiratory airflow, mean expiratory airflow, and expiratory volume. She also completed a series of assessments to assess her intelligibility, quality of life, communicative participation, and her cognition.

Results:

While a few of the measures trended toward significance, there was no noticeable change in any of Betty’s acoustic or aerodynamic measures collected during Clear Speech intervention. There were notable results in her assessment data, with most test results improving or maintaining from baseline to follow-up. Notable test results that changed from baseline to follow-up included decreased Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) scores, increased Communication Participation Item Bank (CPIB) scores, maintaince of very high Speech Intelligibility Test (SIT) scores, and decreased Voice Handicap Index (VHI) scores.

Conclusion:

The results of this study show that while there was no significant change in Betty’s acoustic or aerodynamic measures following Clear Speech Intervention, she did report improvements in her communicative participation and perceived voice quality. While there no observed change in any of Betty’s acoustic and aerodynamic measures, there was also no evidence of disease progression on her speech. More research is needed to investigate the impact of Clear Speech Intervention for more individuals and for other domains of speech production, such as articulation and speech prosody.

Download

Share

COinS