These annotations are then used to compute the gold standard using different methods, and a series of regression experiments is conducted to evaluate their impact on the performance of a regression model predicting the degree of naturalness of L2 speech.
additionally, to add some more specialised (but still text-independent features) we also compute duration, rhythm, and prosodic features derived from a segmentation of the recordings into vocalic and consonantal intervals, and from pseudo-syllables derived from that segmentation.