File descriptions Data files are available for download from this page. File descriptions train.npy - training features ; train_labels.npy - training labels ; dev.npy - development/validation features ; dev_labels.npy - development/validation labels ; test.npy - test features ; sample.csv - sample submission in correct format ; phonemes.txt - distinct phonemes Feature Files [train|dev|test].npy contain a numpy object array of shape [utterances]. Each utterance is a float32 ndarray of shape [time, frequency], where time is the length of the utterance. Frequency dimension is always 40 but time dimension is of variable length. Label Files [train|dev]_labels.npy contain a numpy object array of shape [utterances]. Each element in the array is an int32 array of shape [time] and provides the phoneme state label for each frame. There are 71 distinct labels [0-70], one for each subphoneme.