Differences in phonetogram features between male and female subjects with and without vocal training

Singing not only requires good voluntary control over phonation and a musical ear, it also demands certain capacities of the voice source. These capacities include a desirable range of sound intensity and frequency, which can be measured and represented in a phonetogram. The influence of specific factors on voice capacities may be ascertained by the analysis of phonetograms. To determine the influence of the factors gender and voice training, phonetograms of 224 subjects, subdivided accordingly into four groups, were analyzed in two different ways. One is based on the rescaling of phonetograms, whereas the other derives analytic variables from the features' shape, area, and dynamic range. Analysis showed that, regarding gender, male subjects are able to produce softer phonations, whereas female subjects produced louder phonations at specific parts of their comparable frequency ranges. Trained subjects have a larger enclosed area of the phonetogram, which is primarily based on extended soft voice capabilities in both genders and the significantly larger frequency range in trained female subjects. The shape analysis, performed with Fourier Descriptors, revealed differences for the factors gender and training.