Issues with intelligibility can be due to a variety of different factors. One cause of unintelligibility can be the voice settings you select in Step 1, which are used to generate the sentences you hear in Step 2. For example, a voice speed that sounds fine in Step 1, when you know the sentences you’re hearing, may suddenly sound too fast in Step 2, when you don’t know what the sentences are. If you’re having trouble with Step 2 and want to go back to Step 1, contact us at staff@modeltalker.org so that we can reset your audition. (Note also that once you complete Step 2, you’ll be able to adjust your settings again in Step 3.)
Also, note that the sentences we use were designed by audio engineers to test the intelligibility of various sound systems, and so were designed to have a challenging range of intelligibilities. These sentences are probably not typical of the kind of sentences you would use with your synthetic voice.