A speech recognition system, method and program product for recognizing speech input from computer users connected together over a network of computers. Speech recognition computer users on the network are clustered into classes of similar users according their similarities, including characteristics nationality, profession, sex, age, etc. Each computer in the speech recognition network includes at least one user based acoustic model trained for a particular user. The acoustic models include an acoustic model domain, with similar acoustic models being clustered according to an identified domain. User characteristics are collected from databases over the network and from users using the speech recognition system and then, distributed over the network during or after user activities. Existing acoustic models are modified in response to user production activities. As recognition progresses, similar language models among similar users are identified on the network. Update information, including information about user activities and user acoustic model data, is transmitted over the network and identified similar language models are updated. Acoustic models improve for users that are connected over the network as similar users use their respective speech recognition system.