Phonetic Question Generation Using Misrecognition

Most automatic speech recognition systems are currently based on tied state triphones. These tied states are usually determined by a decision tree. Decision trees can automatically cluster triphone states into many classes according to data available allowing each class to be trained efficiently. In order to achieve higher accuracy, this clustering is constrained by manually generated phonetic questions. Moreover, the tree generated from these phonetic questions can be used to synthesize unseen triphones. The quality of decision trees therefore depends on the quality of the phonetic questions. Unfortunately, manual creation of phonetic questions requires a lot of time and resources. To overcome this problem, this paper is concerned with an alternative method for generating these phonetic questions automatically from misrecognition items. These questions are tested using the standard TIMIT phone recognition task.