From Going Public by Arlene Stein and Jessie Daniels, pg 80-81:

An author’s voice is simply his or her “unique authorial fingerprint,” according to Theresa MacPhail, a New York University professor of science and technology studies. 19 If an author has a distinctive voice, she writes, “then we can often accurately attribute a text to its correct author even if her identity is concealed.” You can tell by her habitual turn of phrase, particular way of organizing a text, or distinctive way of talking with her readers. In graduate school, social scientists often learn how to shed their distinctive voices. Some journal editors even seem to require it. But retaining that voice can make one’s prose more engaging and show that it is written by a living, breathing, human being who is passionate about a particular subject—and wishes to convey her understanding of it to others. All readers like to know something about their authors, and appreciate an author whose voice is clear and resonant, with whom they can identify.