Why are familiar-only experiences more frequent for voices than for faces?

Hanley, Smith, and Hadfield (1998) showed that when participants were asked to recognize famous people from hearing their voice, there was a relatively large number of trials in which the celebrity's voice was felt to be familiar but biographical information about the person could not be retrieved. When a face was found familiar, however, the celebrity's occupation was significantly more likely to be recalled. This finding is consistent with the view that it is much more difficult to associate biographical information with voices than with faces. Nevertheless, recognition level was much lower for voices than for faces in Hanley et al.'s study, and participants made significantly more false alarms in the voice condition. In the present study, recognition performance in the face condition was brought down to the same level as recognition in the voice condition by presenting the faces out of focus. Under these circumstances, it proved just as difficult to recall the occupations of faces found familiar as it was to recall the occupations of voices found familiar. In other words, there was an equally large number of familiar-only responses when faces were presented out of focus as in the voice condition. It is argued that these results provide no support for the view that it is relatively difficult to associate biographical information with a person's voice. It is suggested instead that associative connections between processing units at different levels in the voice-processing system are much weaker than is the case with the corresponding units in the face-processing system. This will reduce the recall of occupations from voices even when the voice has been found familiar. A simulation was performed using the latest version of the IAC model of person recognition (Burton, Bruce, & Hancock, 1999) which demonstrated that the model can readily accommodate the pattern of results obtained in this study.