The Effect of Gesture on Speech Production and Comprehension
Driskell, James E., Radtke, Paul H., Human Factors
Cairncross (1997) coined the phrase "the death of distance," suggesting that distance may no longer be a limiting factor in people's ability to communicate. In fact, telecommunications systems are becoming ubiquitous in business and he military, allowing expert-novice, instructor-learner, or peer-peer communication to occur among interactants who are spatially separated. Various terms are used to describe this type of communications environment, including video-mediated communication, remote collaboration, and point-to-point teleconferencing; however, the core features include two or more remotely located people who send and receive audio, video, and data via a desktop computer or teleconferencing system. Although telecommunications systems can be used to support almost any type of communications, the emphasis in many applied settings is on technical communications such as training, job aiding and support, and information exchange.
Fussell and Benimoff (1995) viewed teleconferencing as an extension of normal communication and argued that the design of effective telecommunications systems is based on an understanding of the processes that facilitate face-to-face communication. Given the importance of gesture to communication, it is surprising that there is little consensus on the role of gesture in telecommunications. Fussell and Benimoff concluded that "the best video field for a desktop video system is one that communicates information conveyed by facial expressions and most gestures" (p. 244). Hayne, Pendergast, and Greenberg (1994) and Isaacs and Tang (1997) concurred that telecommunications systems that do not support gesture provide an impoverished communication environment. However, Doherty-Sneddon et al. (1997) reported that visual access to the upper body and gestural information was not critical to users in video-mediated communications.
At least in part, this disagreement regarding the value of gesture in telecommunications stems from the lack of a fundamental understanding of the role that gesture plays in normal communication. To what extent does gesture aid the listener in comprehending speech? To what extent does gesture aid the speaker in formulating speech? Is gesture more valuable for some types of speech content than for others? Whittaker and O'Conaill (1997) concluded that "We need more detailed understanding of the precise functions that visual information plays in communication" (p. 24), noting that prior work in designing telecommunications systems was based on the intuition that visual information would benefit interaction, without an understanding of how these benefits will come about. Before the role of gesture in design questions such as field of view and quality and size of the video image required for teleconferencing can be effectively discussed, the precise role that gestures play in communication needs to be more fully understood. Therefore, the purpose of this study was to examine the role that gesture plays in aiding the speaker and the listener in communication. More specifically, we examine the relationships among gesture, speech production, and listener comprehension.
GESTURES, SPEECH PRODUCTION, AND COMPREHENSION
Hand gestures play an integral role in communication. For example, even in brief conversation, gestures may be observed that are used to point out objects, coordinate speech, and express emotions; that serve as symbols (e.g., a thumbs-up sign); and that elaborate speech. A number of typologies have been offered to capture these various functions of gesture in conversation (Efron, 1941/1972; Ekman & Friesen, 1972; McNeill, 1985). Common to all of these classifications is the category of conversational hand gestures. Conversational hand gestures are hand movements that accompany speech. Although distinctions can be made among different types of conversational gestures, our concern is with that class of gestures that have been termed iconic, illustrative, or lexical (see Krauss, Chen, & Chawla, 1996; McNeill, 1985; Rime & Schiaratura, 1991). …