An electronic device (400) for speech dialog includes functions that receive (405, 205) a speech phrase that includes an instantiated variable (315), generate pitch and voicing characteristics (330) of the instantiated variable, and performs voice recognition (410, 220) of the instantiated variable to determine a most likely set of recognition acoustic states (335). A trained map (358) is established (115) that maps recognition feature vectors derived from training speech (105) to synthesis feature vectors derived from the same training speech (110). Recognition feature vectors that represent the most likely set of recognition acoustic states for the recognized instantiated variable are converted to a most likely set of synthesis acoustic states (420) in accordance with the map. The electronic device may generate (421, 440, 445) a synthesized value of the instantiated variable using the most likely set of synthesis acoustic states and the pitch and voicing characteristics extracted from the instantiated variable.