182 HUMAN COMMUNICATION RESEARCH / April 2004 Human Communication Research, Vol. 30 No. 2, April 2004 182–207 © 2004 International Communication Association The Multiple Source Effect and Synthesized Speech Doubly-Disembodied Language as a Conceptual Framework KWAN MIN LEE University of Southern California CLIFFORD NASS Stanford University Two experiments examine the effect of multiple synthetic voices in an e-commerce context. In Study 1, participants (N = 40) heard five positive reviews about a book from five different synthetic voices or from a single synthetic voice. Consistent with the multiple source effect, results showed that participants hearing multiple synthetic voices evaluated the reviewed books more positively, predicted more favorable public reaction to the books, and felt greater social presence of virtual speakers. The effects were mediated by participants’ feelings of social presence. The second experiment (N = 40) showed that the observed effects persisted even when participants were shown the purely artificial nature of synthesized speech. These re- sults support the idea that characteristics of synthetic voices in doubly disembodied language settings influence participants’ imagination of virtual speakers, and that technological lit- eracy does not hinder social responses to anthropomorphic technologies such as text-to-speech (TTS). M any forms of mediated communication such as newspapers, radio, films, TV, and computers include disembodied language, “language that is not being produced by an actual speaker at the moment it is being interpreted” (Clark, 1999, p. 1). Disembodied lan- guage is quite abundant in everyday life and most people understand it with no difficulties. Consequently, people tend to think that the interpre- tation of disembodied language is a trivial process. Clark (1996, 1999) argued, however, that the process for interpreting disembodied language is a remarkable one: Through imagination, people must visualize virtual speakers who have written or spoken sentences in disembodied language. Kwan Min Lee (Ph.D., Stanford University) is an assistant professor at the Annenberg School for Communication, University of Southern California; Clifford Nass, (Ph.D., Sociology, Princeton University, 1986) is a professor in the Department of Communication, Stanford University. This study is based on the first author’s doctoral dissertation, for which the second author was major advisor. Correspondence may be addressed to Kwan Min Lee, Annenberg School for Communication, 3502 Watt Way, University of Southern California, Los Angeles, CA 90089: email: kwanminl@usc.edu.