25. The system of claim 16 , wherein the one or more computer processors are configured to generate the first updated acoustic model based at least in part on the first confidence value associated with the first speech recognition results by: generating a weight based on the confidence value associated with the first speech recognition results; and generating the first updated acoustic model by using the weight to adjust a Gaussian distribution of the acoustic features of the acoustic model.
29. The system of claim 25 , wherein: the acoustic model further comprises one or more hidden Markov models representative of one or more sound units; a state of a hidden Markov model of the one or more hidden Markov models is represented as a Gaussian mixture model comprising a linear combination of a plurality of Gaussian distributions; and the Gaussian distribution of the acoustic features associated with the acoustic model is included in the plurality of Gaussian distributions.