Vocal function is assessed in 15 patients who received thyroplasty type I for rehabilitation of unilateral vocal fold paralysis. Function is assessed by perceptual evaluation, voice intensity and frequency range profile, and questionnaire. Goals of the study are: to evaluate efficacy of thyroplasty in improving voice; to compare postoperative thyroplasty voice to normal voices; and to correlate objective measurements to the results of the questionnaire regarding satisfaction with voice. Perceptual evaluations were performed by randomizing normal and thyroplasty voices on a recording tape. The voices on the tape were then rated by independent, blinded, trained listeners. The perceptual qualities of pitch, intonation, and loudness were not statistically different than normals; however, voice qualities of breathy hoarse, harsh and unsteady were different than normals. Mean frequency range and mean intensity range was moderately to severely reduced from normals with a wide variation being present in the results. The correlation between the higher threshold phonation pressures and decreased intensity ranges found in some patients is discussed.
Questionnaire results indicate that a high degree of satisfaction with the surgery is present (92%). Extreme or general satisfaction with the voice was present in 73%. The most difficult voicing is experienced at work with 25% needing to adjust their employment to accommodate their voice abilities. These results indicate that thyroplasty type I is effective in partially rehabilitating unilateral vocal fold paralysis. Voice function is still not normal, probably in part due to the underlying disease.