At the Institute of Telecommunications of the Technical University of Berlin, three speech assessment experiments were performed to compare the Modulated Noise Reference Unit (MNRU)  and the time and frequency warping (TFW) reference system . To perform this evaluation, a category rating test procedure similar to ITU-Rec. P.85  was implemented in an evaluation system developed at the Institute of Telecommunications . This paper explains in the first part details of the reference systems and summarises the evaluation results of both systems individually (sections 1 to 3). Section 4 compares of the assessment results by a number of synthec speech samples that were commonly used in all experiments. Keywords: synthetic speech, category rating test, reference systems, modulated noise reference unit, time frequency warping
Bibliographic reference. Klaus, H. / Niebank, A. (1995): "Comparison of reference system approaches for the quality assessment of synthesized speech", In EUROSPEECH-1995, 1267-1270.