Recognition of hesitations in spontaneous speech

Both filled and unfilled (silent) hesitation types of pauses in a widely used speech database were examined for both unintended and intended pauses. A distinction is made between grammatical pauses (at major syntactic boundaries) and ungrammatical ones (within minor syntactic phrases). While unfilled pauses cannot be reliably thus separated based on silence duration alone, grammatical pauses tended to be longer. In the prepausal word before ungrammatical pauses, there were few continuation rises in fundamental frequency (F0), whereas 70% of the grammatical pauses were accompanied by a prior F0 rise. Identifying the syntactic function of such pauses could improve the performance of an automatic speech recognizer, by eliminating from consideration some hypotheses based on spectral analysis. Results are given which could allow simple identification of most filled and unfilled pauses and their syntactic function