This method and tool visualizes systematic speaker group differences. It compares two sets of realizations of the same sentence (assuming no word insertions, deletions, or substitutions). More information can be found in

• Sebastian Wankerl, Florian Hönig, Anton Batliner, Juan Rafael Orozco-Arroyave, Elmar Nöth: Visual Comparison of Speaker Groups, Proceedings of INTERSPEECH 2015, Dresden, to appear.
• Florian Hönig, Sebastian Wankerl, Anton Batliner, Elmar Nöth: Pinpointing the Difference - Visual Comparison of Non-Native Speaker Groups, Proceedings of SLaTE 2015, Leipzig, to appear.

The tool is available as a python implementation.