Recent developments in speech, network and embedded computer technologies indicate that human computer interfaces that use speech as one or the main mode of interaction will become increasingly prevalent. such interfaces must move beyond simple voice commands to support a dialogue based interface to support human computer dialogue effectively,architectures must suppor t active language understanding.it is generally accepted that using context in conjunction with a human input, such as spoken speech, enhances a machine's understanding of the user's intent as a means to pinpoint an adequate reaction. the contribution of this work is to provide empirical evidence of the importance of conversational context in speech based human computer interaction. a framework for context sensitive computing approach is presented, to address how to extract contexts from speech, how to process contextual entities by developing an ontology based context model and how to utilize this approach for real time decision making to optimize the performance indicators .