The Parallel Encoding and Target Approximation (PENTA) Model
Xu (2005)

- F0 conveys multiple layers of communicative functions that are parallel to each other (far left).
- Each function is directly coded by an encoding scheme (second left) which specifies the values of the articulatory parameters (middle) for the TA process (second right).
- The TA model then generates surface F0 through the process of syllable-synchronized sequential target approximation.
- Thus surface F0 is not directly specified by any phonological or phonetic units. Rather, it is generated by the TA process whose control parameters are specified by the encoding schemes, each corresponding to a specific communicative function.