Comparison of Post-therapy Dysphonic Voices and Normal Voices

Abstract

The purpose of the present investigation was to compare the voices of post-therapy dysphonic participants with participants who have normal voices to determine how close the corrected voices approached normal vocal levels. The present investigation is a follow-up to the authors' previous research in which dysphonic participants, with voices ranging from moderate-to-severe dysphonia, were evaluated pre- and post therapy using the Dysphonic Severity Percentage scale and the interval scale. In the present study, five raters, three speech-language pathologists experienced in assessing dysphonia, and two trained speech-language pathology college students evaluated 20 participants with normal voices under the same two conditions as those of the corrected participants-when reading a paragraph aloud and during spontaneous speech. While listening to the recordings of the normal voices, the raters tallied any dysphonic syllables produced by the participants to obtain a Dysphonic Severity Percentage for both paragraph reading and spontaneous speech. The raters also evaluated the normal voices on the interval scale. These data were compared with those of the post-therapy participants, who were evaluated under the same conditions and methods pre- and post therapy. The dysphonic participants' voices improved significantly post therapy in comparison with their pretherapy result; their improvement, however, was not commensurate with the voices of the normal participants, and the data showed a significant difference between the two groups. Both evaluation scales reflected a high agreement among raters.