Standardization and Feasibility of Voice Range Profile Measurements in Epidemiological Studies

The voice range profile (VRP) is composed of the speaking VRP (spVRP) and the singing VRP (siVRP). Different examination methods of VRP and effects of interobserver variability were evaluated to define a standard operating procedure (SOP) suitable for the specific use in epidemiological studies. Subsequently the feasibility of the SOP was investigated in a larger number of participants.

Cross-sectional study.

In a first phase both the spVRP and the siVRP of 51 female students were measured by four differently experienced examiners. Using a cross-over study design the effects of two different recording methods (manual vs automatic) and three different types of instructions given by the examiner (none vs before vs during recording) were investigated. In a second phase, the SOP for VRP recording was tested in the framework of a feasibility study in 110 (55 female and 55 male) participants.

The average total investigation time was significantly (P = 0.001) higher for the manual recording method (6.1 minutes ± 1.0) in comparison to the automated (5.5 minutes ± 0.7) recording method. The manual recording method led to significantly lower values of minimum frequency (F0min) (P = 0.013) and minimum intensity (SPLmin) (P < 0.001) and higher values of the maximum frequency (F0max) (P = 0.005) of the siVRP. The maximum phonation time, F0max, SPLmax of the siVRP and the frequency and intensity of the shouting voice (Level IV) of the spVRP showed significantly (P < 0.001) higher values when the examiner was allowed to give instructions and advise during the recording. Voice parameters of the siVRP did not show significant associations with the experience of the examiner.

Standardization of VRP measurements is important to obtain correct and reproducible data in a reasonable examination time. The SOP proposed here proved to be feasible in the setting of an epidemiological study.