Concerned with pathological voice assessment, this paper aims at characterizing dysphonia in the frequency domain for a better understanding of relating phenomena while most of the studies have focused only on improving classification systems for diagnosis help purposes. In this context, a GMM-based automatic classification system is applied on different frequency ranges in order to investigate which ones are relevant for dysphonia characterization. Experiment results demonstrate that the low frequencies [0-3000]Hz are more relevant for dysphonia discrimination compared with higher frequencies.