Disease related changes in vocal parameters of patients with type 2 diabetes mellitus.

Background: As the duration of diabetes progresses, various disease related complications might occur in patients. The main goal of this paper is to compare acoustic and aerodynamic measures of patients with type 2 diabetes mellitus (T2DM) with a control group of healthy subjects.

Methods: A total of 91 subjects, 51 individuals with type 2 diabetes mellitus (DM group) and 40 healthy volunteers (HV group) were participated in the study. Maximum phonation time (MPT) was captured for assessing phonatory mechanics. Acoustic voice parameters, including mean fundamental frequency (mean fo), jitter local (Jlocal), jitter absolute (Jabs), shimmer local (Slocal), shimmer decibel (SdB), and harmonics to noise ratio (HNR) were detected using the Praat software program.

Results: Only for Jabs, statically significant difference was found between the groups. There were no statically significant differences between any voice parameters of HV versus those with the duration of diabetes ≥10 years and the HbA1c level ≥7%. However, statically significant differences for MPT and Slocal were found between patients with neuropathy versus HV. In addition, a comparison between patients with voice complaint versus HV showed significant differences for Slocal and SdB.

Conclusions: The findings of the present study do not provide strong evidence about the possible effect of DM on the human voice. However, diabetic neuropathy is considered to be a factor affecting the voice parameters in the target population. The physicians should pay attention to the acoustic and aerodynamic voice parameters in patients with diabetes, particularly in those with neuropathy or voice complaints.