This paper tests the idea that the speech rate with which surrounding words are spoken affects the mental representation of words and conditions production of words. This possibility is operationalized by measuring a word's ratio of occurrence in speaker-relative fast speech. Other variables shown in the literature to influence speech rate are controlled for in a 10,000-iteration bootstrapping procedure of a mixed-effect linear regression model. The results of the analysis of 39,397 tokens of content words from 1,232 word types in English display a significant effect for a word's ratio of conditioning in speaker-relative fast speech, although the effect size is small or very small. Other variables shown in the literature to condition speech rate also significantly condition speech rate here. This paper suggests that in addition to other aspects of the context of use of words, contextual speech rate also influences the mental representation of words.

We explore the properties of foreigner talk through word reduction. Word reduction signals that the speaker is referring to the same entity as previously and should be preserved for foreigner talk. However, it leads to intelligibility loss, which works against foreigner talk. Pairs of speakers engaged in a task where native speakers talked either to a native or non-native listener. Natives talking to non-natives performed foreigner talk for duration and intensity. Duration and intensity were reduced for native and non-native listeners equally. These results suggest that word reduction is insensitive to communicative adjustments in the context of foreign talk.

Speakers frequently have a choice among multiple ways of expressing one and the same thought. When choosing between syntactic constructions for expressing a given meaning, speakers are sensitive to probabilistic tendencies for syntactic, semantic or contextual properties of an utterance to favor one construction or another. Taken together, such tendencies may align to make one construction overwhelmingly more probable, marginally more probable, or no more probable than another. Here, we present evidence that acoustic features of spontaneous speech reflect these probabilities: when speakers choose a less probable construction, they are more likely to be disfluent, and their fluent words are likely to have a relatively longer duration. Conversely, words in more probable constructions are shorter and spoken more fluently. Our findings suggest that the differing probabilities of a syntactic construction in context are not epiphenomenal, but reflect a part of a speakers' knowledge of their language.