Pipelining Acoustic Model Training for Speech Recognition Using Storm

Speech recognition has been increasingly used on mobile devices, which has in turn increased the need for creation of new acoustic models for various languages, dialects, accents, speakers and environmental conditions. This involves training and adapting a huge number of acoustic models, some of them in real-time. Training acoustic models is thus essential for speech recognition because these models determine the accuracy and quality of the recognition process. This paper, discusses the use of Storm, a distributed real time computational system, to pipeline the creation of acoustic models by CMU Sphinx, an open-source software project for speech recognition and training. Software pipelining reduces the time required for training and optimizes system resource utilization, thus enabling huge amounts of data to be trained in considerably less amount of time than taken by the conventional sequential process. Pipelining is achieved by grouping the stages of the training process into a set of five stages, and running each stage on individual nodes in a Storm cluster. Thus acoustic models are created by training multiple streams of speech samples using the same SphinxTrain setup, also resulting in improvement of training time and throughput.