COMPLEXITY EFFECTS ON TEMPORAL CHARACTERISTICS OF SPEECH

In light of evidence that multiple-goal messages tend to be characteri zed by longer speech-onset latencies and higher pause-phonation ratios , Greene, McDaniel, Buksa, and Ravizza have suggested that it is not t he pursuit of multiple goals, per se, that results in less fluent spee ch. Rather, these authors suggest that the slower speech production ch aracteristic of such messages is the result of difficulties in assembl ing, or integrating, incompatible message features. Recent evidence, h owever, indicates that this account is incomplete and in need of revis ion. Toward this end, we advance a complexity account that suggests th at there are increased processing-capacity and temporal demands associ ated with formulating and maintaining more complex message representat ions. The article then reports four experimental studies of this compl exity account. Experiments 1 and 2 operationalize complexity as the am ount of information to be communicated in a message. These studies ind icate that complexity does affect pause-phonation ratio and average pa use duration. Experiments 3 and 4 operationalize complexity as the coh erence of the information to be conveyed in a message. The results of Experiment 4, but not Experiment 3, again indicated that complexity in fluences speech fluency. The results of these studies, then, are taken to provide considerable support for the complexity hypothesis.