1. A method, comprising: receiving one or more speech recognition parameters prior to issuing a verbal prompt to a user; issuing a verbal prompt to the user; receiving an acoustic input from the user in response to the verbal prompt; processing one or more sequences of phonemes to obtain one or more acoustic representations, wherein the one or more sequences of phonemes are generated from a list of expected responses to the issued verbal prompt; comparing the acoustic input from the user to the one or more acoustic representations to determine an acoustic channel characterization and/or speaker class; and adjusting one or more speech recognition parameters based on the comparison, wherein the adjustment comprises applying feature space mapping to the acoustic input, and further wherein the one or more adjusted speech recognition parameters are used to adjust a speech recognition module of a speech recognition system to use an acoustic model that is consistent with an acoustic channel characterization and/or speaker class so that the selected acoustic model is used for decoding subsequent acoustic input provided by the user as the conversation progresses; wherein the steps are performed by at least one processor device coupled to a memory.