Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: A new approach to the analysts of voice quality

Purpose: The study of acoustic voice parameters (fundamental frequency, jit ter, shimmer, and harmonics-to-noise ratio) in extended vowel production, o ral reading of a standard paragraph, spontaneous speech and a song in irrad iated patients for Tis-T1 vocal cord carcinoma. Methods and Materials: Eighteen male patients irradiated for Tis-T1 vocal c ord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the eases and a vocal cord bi opsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2), Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patie nts in extended vowel production, oral reading of a standard paragraph, spo ntaneous speech, and in a song was tape registered and analyzed by a Kay El emetric's Computerized Speech Lab (model CSL# 4300), Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests. Results: The irradiated group presented higher values of fundamental freque ncy, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis s howed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showe d differences in vowel production and harmonics-to-noise ratio in oral read ing and song. Conclusions: In our study only fundamental frequency and jitter showed sign ificant increased values to the control group in all the acoustic situation s. Sustained vowel production showed the worst values of the acoustic param eters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field. (C) 2000 Elsevier Sci ence Inc.