The objective of the present work is to improve the digit recognition performance of speech signals affected with dysarthria. The paper presents preliminary studies performed on universal access dysarthric speech recognition (UADSR) database. The works presented in the paper are organized into three stages. Firstly, the degradation in the digit recognition performance is demonstrated by testing the dysarthric digits with the acoustic models built using the digit samples spoken by controlled speakers. Secondly, the prosodic analysis is performed on the dysarthric isolated digits that are available in the database. Finally, the prosodic parameters of the dysarthric speech is manipulated to match with the normal speech which is used to build the acoustic models. Based on the experiments conducted, the manipulation of duration parameters using the state of the art time-domain pitch synchronous overlap add (TD-PSOLA) method observed to be significantly improving the recognition rates in contrast to other prosodic parameters. The improvement in the word recognition rates are also found to be in accordance with the intelligibility of the dysarthric speakers and hence proves the significance of using customized prosodic scaling factors according to the intelligibility levels of each of the subjects.
Vishakh, A., Govind, D., & Pravena, D. (2015). Preliminary Studies towards Improving the Isolated Digit Recognition Performance of Dysarthric Speech by Prosodic Analysis. In Procedia Computer Science (Vol. 58, pp. 395–400). Elsevier B.V. https://doi.org/10.1016/j.procs.2015.08.046