Long time residents of Nashville believe that the the voices belong to the ghosts of two men who have had an intimate relationship with the capitol building. The full story of the haunted capitol can be found here.
The first man was William Strickland who was hired in 1845 to be the architect for the new capitol. Strickland was recruited from Philadelphia. He planned to complete the job in Tennessee and return to his home in Philadelphia, but fate intervened.
The second man was Samuel Morgan who was hired by the Capitol Commission to oversee the construction, including the work done by Strickland. According to the story, the two men hated each other at first sight, and quarelled endlessly over the project.
In 1854, nine years later, Strickland passed away before the capitol building was completed. In his memory, the state honored Strickland's contribution by constructing a vault within the capitol in which Strickland's body would be interred. It was considered a rare honor, and the only other person in the state's history who was granted a burial place within the capitol was Strickland's mortal enemy, Samuel Morgan.
Police officers frequently answer disturbance calls complaining about the loud voices of two men arguing, but when the incidents were investigated, no one was ever found. Often the location of the arguments is at the north foundation wall of the capitol, which is where the two men are entombed.