Injection Laryngoplasty of Unilateral Vocal Fold Paralysis Evaluated With Pause and Speech Measurements

The purpose of this study was to examine a number of pause-and-speech-measurements in patients with unilateral vocal fold paralysis, before and after injection laryngoplasty. The non-invasive measurements were selected to investigate and explain the treatment effect on connected speech in these patients.

Retrospective study with repeated measurements design.

Voice recordings of 24 patients with unilateral vocal fold paralysis from before and after injection laryngoplasty in local anesthesia were analyzed retrospectively with the computer program Praat. Measurements examined were number of pauses, average pause duration, pause ratio (expressing the amount of pausing during a reading-aloud task), number of breath groups, average duration of breath groups, articulation rate, speaking rate, maximum phonation time, and Voice Handicap Index.

Injection laryngoplasty had a significant improving effect on the number of pauses, pause ratio, number of breath groups, average duration of breath groups, articulation rate, speaking rate, maximum phonation time, and Voice Handicap Index. Maximum phonation time before treatment correlated with several pause and speech measurements.

The results showed that treatment with injection laryngoplasty had a clear effect on several pause and speech measurements and that these measurements correlated with maximum phonation time, but not with Voice Handicap Index.