Some commercial synthetic voices sound almost perfectly human. Why won’t my ModelTalker voice sound that good?

The technology in ModelTalker is similar to that used for some of the very best commercially available voices, but there are also many important differences. The highest quality commercial voices are constructed from many hours of recordings made under studio conditions by professional speakers who work with technicians to record everything in exactly the best possible way. Even though it may take you several hours to record the sentences for a ModelTalker voice, there will only be about an hour of actual speech recorded for your voice. In a commercial system, there may be 20 times as much speech, or even more!