Voice and advertising: effects of intonation and intensity of voice on source credibility, attitudes toward the advertised service and the intent to buy.

Voice has been neglected in research on advertising and attitude change. In an experiment with 2 x 2 x 2 factorial design (N = 279), several hypotheses derived from the Elaboration Likelihood Model and from phonetic literature were tested; 2 linguistically similar advertising messages on financial services of high (student loan) versus low (Automatic Teller Machine cards) involvement are recorded by a professional actor using 4 types of voice (2 levels of intonation of voice x 2 levels of intensity). Analysis by a system of simultaneous equations indicated that the effects of voice are different under low and high involvement. Intensity of voice affects credibility of the source significantly more under low than high involvement; intonation of voice affects credibility more under high than low involvement. Unexpectedly, characteristics of voice affect attitudes toward the advertised service and intent to buy.