1. A speech processing system comprising: a speech recognition unit to receive input speech, said speech recognition unit performing speech recognition on input speech using acoustic models to produce a speech recognition result; and a natural-language processing unit to perform natural language processing on said speech recognition result, said natural-language processing unit including: a machine translation unit configured to receive and translate said speech recognition result and a reply to said speech recognition result; a dialog management unit configured to generate said reply to said speech recognition result; and a feedback unit configured to feed back information obtained as a result of the natural language processing performed in said machine translation unit and said dialog management unit, said feedback information including adaptation zones, wherein said speech recognition unit operates to process said feedback information including said adaptation zones to adapt the acoustic models so that said speech recognition unit produces said speech recognition result with higher precision than when said adaptation zones are not used.