[The voice of the singer in the phonetogram].

Phonetograms were subdivided into areas approximating voice registers. By means of an analytical description of the areas, parameters could be established for a differentiation of voice categories and efficiency. The evaluation of 21 untrained and 34 trained voices showed a significant difference between the two groups. Male singers demonstrated more efficiency in the head and chest registers than male non-singers; female singers showed a stronger efficiency only in the head voice in comparison with their non-singer counterparts. Proceeding from voice sound alone, voices are often misclassified regarding the voice categories, and voice problems arise. Moreover, enhanced training of only chest or head voice function results in functional disorders in the singing voice. Such cases can be demonstrated by means of phonetograms.