Posterior Probability Based Confidence Measures Applied to a Children’s Speech Reading Tracking System
Daniel Bolaños, Wayne Ward · DSpace repository (University of Tartu) · 2007
In this paper, we present improved wordlevel confidence measures based on posterior probabilities for children's oral reading continuous speech recognition.Initially we compute posterior probability based confidence measures on word graphs using a forward-backward algorithm.We study how an increase of the word graph density affects the quality of these confidence measures.For this purpose we merge word graphs obtained using three different language models and compute the previous confidence measures over the resulting word graph.This produces a relative error reduction of 8% in Confidence Error Rate compared to the baseline confidence measure.Moreover the system operating range is increased significantly.