One of the less studied aspects in human voice processing is how the transition articulations between phonemes occur in fluent speech. Often, lack of information pushes us to deal with them using black-box approach. This is especially true in the field of voice synthesis. In this article the transitions from nasal consonant to every possible vocalic allophone of Spanish language is analyzed using a cycle based nonlinear transition model. This method has been successfully used in every transition between voiced allophones. The data showed in this paper corresponds to the Riverplatean Spanish.