This particularity can be exploited in speech synthesis to model additional information in the speaker models such as speaking styles or emotions (Nose and Kobayashi, 2012;Ling et al., 2013), and it has been used for applications as varied as generating walking motion models (Niwase et al., 2005).
in real life expressiveness present overlap between them because there are not clear frontiers, so being able to take into account those overlaps in the shape of a dynamic synthesizer would be ideal.