An electronic device (300) for speech dialog includes functions that receive (305, 105) a speech phrase that comprises a request phrase that includes an instantiated variable (215), generate (335, 115) pitch and voicing characteristics (315) of the instantiated variable, and performs voice recognition (319, 125) of the instantiated variable to determine a most likely set of acoustic states (235). The electronic device may generate (335, 140) a synthesized value of the instantiated variable using the most likely set of acoustic states and the pitch and voicing characteristics of the instantiated variable. The electronic device may use a table of previously entered values of variables that have been determined to be unique, and in which the values are associated with a most likely set of acoustic states and the pitch and voicing characteristics determined at the receipt of each value to disambiguate (425, 430) a newly received instantiated variable.