19. A system outputting audio content and displaying textual content, the system comprising: a data store; and a processor in communication with the data store, the processor operative to: generate audio content based at least in part on textual content; cause output of the generated audio content; cause presentation of the textual content; obtain an input pointer referencing a position within the textual content being presented; during advancement of the output pointer, determine, independent of the obtained input pointer, a position in the textual content corresponding to the current output position of the generated audio content; determine a segment of textual content based at least in part on a difference between the determined position within the textual content and the position within the textual content referenced by the input pointer; determine a length of the segment of textual content; and modify an attribute associated with the output of the generated audio content based at least in part on the determined length of the segment of textual content.
19. A system outputting audio content and displaying textual content, the system comprising: a data store; and a processor in communication with the data store, the processor operative to: generate audio content based at least in part on textual content; cause output of the generated audio content; cause presentation of the textual content; obtain an input pointer referencing a position within the textual content being presented; during advancement of the output pointer, determine, independent of the obtained input pointer, a position in the textual content corresponding to the current output position of the generated audio content; determine a segment of textual content based at least in part on a difference between the determined position within the textual content and the position within the textual content referenced by the input pointer; determine a length of the segment of textual content; and modify an attribute associated with the output of the generated audio content based at least in part on the determined length of the segment of textual content. 22. The system of claim 19 , wherein obtaining the input pointer referencing the position within the textual content comprises obtaining the input pointer from an input device.