The 1st Workshop on Child, Computer and Interaction (WOCCI2008)

Chania, Crete, Greece
October 23, 2008

A Novel Corpus of Children’s Disordered Speech

Oscar Saz, William Rodríguez, Eduardo Lleida, Carlos Vaquero

Communications Technology Group (GTC), Aragon Institute for Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain

This paper introduces the acquisition, evaluation and baseline Automatic Speech Recognition (ASR) experiments of a novel corpus containing speech from a set of impaired and unimpaired young speakers. A group of 14 speakers with different speech disorders have uttered several sessions over a 57-word vocabulary in Spanish to gather more than 3 hours of speech. In addition to this work, a parallel corpus of speech from unimpaired young speakers has been recorded with more than 6 hours of speech with the same vocabulary. The impaired speech corpus has been evaluated through a manual labeling to detect the mispronunciations made by the speakers, and the outcome of this work show that 17.31% of the phonemes have been either mispronounced or deleted in an isolated work task. A baseline evaluation of the performance of an state-of-the-art ASR system shows a 35.02% of Word Error Rate (WER) when using Speaker Independent models based on adult speech. This WER is reduced to 27.60% using models based on children speech and further reduced to 15.35% using speaker dependent models. Finally, experiments on connected speech show how ASR performance degrades on 4 impaired speakers on the transition from isolated words to connected speech due to the language impairments of the speakers and the coarticulation in connected speech.

Full Paper

Bibliographic reference.  Saz, Oscar / Rodríguez, William / Lleida, Eduardo / Vaquero, Carlos (2008): "A novel corpus of children²s disordered speech", In WOCCI-2008, paper 13.