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.
27. The system of claim 25 , wherein the one or more computer processors are configured to generate the first updated acoustic model by using the weight to adjust the Gaussian distribution of the acoustic features of the acoustic model by: determining acoustic features of a sound unit represented in the first signal; determining a Gaussian distribution of the acoustic features of the sound unit; determining a mean of the Gaussian distribution of the acoustic features of the sound unit; determining a difference between the mean of the Gaussian distribution of the acoustic features of the sound unit and a mean of the Gaussian distribution of acoustic features associated with the acoustic model; and adjusting the mean of the Gaussian distribution of acoustic features of the acoustic model based on the weight and the difference between the mean of the Gaussian distribution of acoustic features of the sound unit and the mean of the Gaussian distribution of acoustic features associated with the acoustic model.