Filled pauses as cues to the complexity of following phrases

Corpus based studies of spontaneous speech showed that filled pauses tended to precede relatively long and complex constituents. We examined whether listeners made use of such a tendency in speech processing. We tested the hypothesis that when listeners heard filled pauses they tended to expect a relatively long and complex phrase to follow. In the experiment participants listened to sentences referring to both simple and compound shapes presented on a computer screen. Their task was to press a button as soon as they had identified the shape that they heard. The sentences involved two factors: complexity and fluency. As the complexity factor, a half of the sentences described compound shapes with long and complex phrases and the other half described simple shapes with short and simple phrases. As the fluency factor phrases describing a shape had a preceding filled pause, a preceding silent pause of the same length as the filled pause, or no preceding pause. The results showed that response times for the complex phrases were significantly shorter after filled or silent pauses than when there was no pause. In contrast, there was no significant difference between the three conditions for the simple phrases. The results support the hypothesis and indicate that it is the duration of filled pauses that give listeners cues to the complexity of upcoming phrases.