Occupational voice complaints and objective acoustic measurements-do they correlate?

To enable the development of appropriate diagnostics and treatment for occupational voice disorders, this study addresses connections between subjective voice complaints and objective observations. The subjects of this study were 24 female customer advisors, who mainly use the telephone during their working hours. During one working day, at four different times, speech samples covering 20 minutes of telephone conversation by the customer service advisors (CSAs) were recorded. In addition, the CSAs filled in a questionnaire (visual analogue scale) concerning their voice problems. To represent the vocal symptoms three variables were used: vocal fatigue, hoarseness and a general sum-variable. A 5-minute sample was taken from recordings for further analyses. This included fundamental frequency, sound pressure level, alpha ratio (the ratio between the spectral energy below and above 1000 Hz) and number of vocal fold vibrations. In the objective acoustic measurements, it was found that fundamental frequency (F0) rose significantly during the working day. Also the self-reported voice symptoms increased significantly during the working day. However, correlations between vocal symptoms and acoustic measures were not found.