Objective: This study was conducted with the purpose of analyzing the effects of hemodialysis on
voice characteristics of patients with chronic renal failure.
Design: A total of 66 patients were participated in the study, including 26 males and 40 females ranging
in age from 19 to 68 years. Patients underwent evaluation of their voice directly before and after
hemodialysis using computerized speech lab (CSL) (4300, Kay Elemetrics Corp.) and Aerophone II
Model 6800 Kay Elemetrics Corp. The vocal acoustic parameters studied include average pitch, jitter,
shimmer and noise-to-harmonic ratio. The aerodynamic parameters include vital capacity, maximum
phonation time, phonation quotient, mean flow rate, sub glottic pressure and glottal efficiency. The
data were analyzed using the paired t-test for the total sample, the male and female subgroups and also
for the patient underwent ultrafiltration with hemodialysis.
Results: In the total sample and in the female subgroup, there is a significant difference in phonation
quotient after hemodialysis. The male subgroup showed no significant differences in all acoustic and
aerodynamic parameters after hemodialysis. The group with positive ultrafiltration showed significant
differences in both vital capacity and phonation quotient after hemodialysis.
Conclusion: There was no effect of hemodialysis on acoustic characteristics of voice; however,
there was a decrease in vital capacity and phonation quotient after hemodialysis especially with
ultrafiltration.
Recommendation: Further studies that include auditory perceptual assessment of voice and
stroboscopic examination of the vocal folds may help in detecting subtle changes that may occur after
hemodialysis.