Date of Defense


Date of Graduation



Speech Pathology and Audiology

First Advisor

Stephen Tasko

Second Advisor

Helen Sharp


Purpose: While many stuttering therapy programs can result in a decrease in stuttering behaviors among participants, some clients leave therapy with speech sounding unnatural due in part to the therapy techniques themselves. The aim of the current study is to examine associations between selected acoustic measures of speaking rate and listener ratings of speech naturalness in a group of adults who stutter following participation in an intensive fluency shaping treatment program.

Methods: Twenty-nine adults who stutter, drawn from an existing database of speech samples, served as participants. All participants had recently completed a four-week group-based intensive fluency shaping treatment program. Pre- and post-treatment measures of stuttering severity using the Stuttering Severity Instrument (SSI) were determined by a team of expert listeners. A group of listeners used a 9-point interval scale to rate the speech naturalness of post-treatment video excerpts drawn from each participant. Acoustic measures taken from the audio channel of the video excerpts included overall speaking rate, articulation rate, and average duration of inter-phrase pausing within the speech sample.

Results: Speech naturalness ratings were not significantly correlated with post-treatment stuttering severity suggesting that speech naturalness was unrelated to frequency of stuttering events and more likely due to treatment variables. Significant, negative correlations were found between speech rate, articulation rate, and speech naturalness ratings. A non-significant positive correlation was found between average pause duration and speech naturalness ratings. Both speech and articulation rate were positively correlated with SSI scores while median pause duration was negatively correlated with SSI scores.

Access Setting

Honors Thesis-Open Access