21. A system comprising: a display device; a memory; and a computing device configured to: access an electronic version of a document; display a sequence of words from the electronic document in a user interface rendered on the display device; apply in response to a user-based selection of a first portion of words in the sequence of words from the document, a first indicium to the user-selected first portion of words in the sequence of words; associate a first narration voice to the first portion of words in the sequence of words; and associate a second narration voice to a second portion of words in the sequence of words, the second portion of the words in the sequence of words being different from the first portion of words in the sequence of words.
21. A system comprising: a display device; a memory; and a computing device configured to: access an electronic version of a document; display a sequence of words from the electronic document in a user interface rendered on the display device; apply in response to a user-based selection of a first portion of words in the sequence of words from the document, a first indicium to the user-selected first portion of words in the sequence of words; associate a first narration voice to the first portion of words in the sequence of words; and associate a second narration voice to a second portion of words in the sequence of words, the second portion of the words in the sequence of words being different from the first portion of words in the sequence of words. 27. The system of claim 21 , further configured to: automatically identify third portions of text in the sequence of words; and automatically associate the third portions of text with a third, different narration voice model.