A distinction between the effects of sentential speaking rate and semantic congruity on word identification

Abstract

It is well known that numerous aspects of sentential context can influence the manner in which a word within the sentence is identified. We investigated two such contextual effects, that of the speaking rate of the sentence in which the target word occurs and that of the semantic congruence between the sentence and the target word. We observed that although the two effects are similar on the surface, in that each is realized as a change in the identification of acoustically ambiguous (but not unambiguous) items along a speech series, they are strikingly different in their susceptibility to changes in task demands. Specifically, changes in the task that readily eliminate the semantic congruity effect do not serve to eliminate the rate effect, suggesting that the two effects arise at different stages of analysis. The implications of this finding for models of speech processing are discussed.It has been known for a long time that the identification of a given word in a sentence is not based solely on its own acoustic and linguistic properties, but depends as well on the acoustic and linguistic properties of the sentence in which it occurs (e.g., G. A. Miller, Heise, & Lichten, 1951;G. A. Miller & Isard, 1963; and see Bagley, 1900-1901, discussed in Cole & Rudnicky, 1983. But although there is a consensus on the existence of such context effects; and continued investigation into the nature of such effects (see, e.g., Forster, 1976;Grosjean, 1980;Marslen-Wilson & Tyler, 1980; Swinney, 1981), the manner in which sentential properties enter into the word recognition process is not yet understood.In the course of investigations of contextual effects in speech perception, we have made an observation concerning the manner in which two different properties of a sentence influence the identification of a word within that sentence. One property is speaking rate, which is defined in terms of physical properties of the speech signal. The other is the semantic congruence between the sentence and the to-be-identified word, which is based on a linguistic, specifically semantic, analysis of the utterance. We have observed that although the two properties have superfi- dally similar effects on the identification of a word, they actually operate quite differently. The existence of the semantic effect is highly dependent on the characteristics of the task demands, whereas this appears not to be true of the rate effect. In particular, changes in the experimental task that readily eliminate the semantic effect do not serve to eliminate the rate effect. The differential sensitivity of the two effects to the experimental task suggests that the effects, although similar on the surface, arise at different stages of analysis. The purpose of the present paper is to report our observation and to discuss its implications for models of speech processing.Our observation is based on two parallel series of studies, one of which focused on speaking rate and the other on semantic congruity. Our methodology in these studies is one that has been used...

Interactions between distal speech rate, linguistic knowledge, and speech environment

“…Cue-weighting, the use of multiple cues to varying degrees depending on a number of factors, has been utilized to account for a variety of linguistic processing phenomena, ranging from phoneme identification (e.g., ; Pisoni & Luce, 1987;Repp, 1982) to syntactic structure (e.g., Beach, 1991). Early work by Miller and colleagues showed that while speaking rate and semantic context influence the perception of acoustically ambiguous phonemes (Miller, Green, & Schermer, 1984), the effect of semantic context on VOT categorization was found only when the experimental task included a judgment identifying the semantic context. This suggests that the experimental context in which a task is performed can also influence cue-weighting.…”

Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate

“…It is unclear at present what predictions these models might make with respect to best-exemplar locations, but any complete model of speech perception must ultimately account for the dissociation we report between an acoustic-phoneticcontextual factor and a higher order linguistic contextual factor concerning the location of category best exemplars. 8 Of course, additional research will be required to determine whether higher order linguistic factors, other than lexical status, that shift category boundary locations, such as sentential-level semantic context (Borsky, Tuller, & Shapiro, 1998;Connine, 1987;Miller, Green, & Schermer, 1984), have the same relatively limited effect on the best exemplars of the category. Our interpretation of the dissociation we have found between the effects of acoustic-phonetic factors and lexical status suggests that this dissociation will indeed generalize to other higher order factors, so long as such factors do not affect the relevant acoustic dimension in speech production.…”

The TRACE model of speech perception

“…It has been suggested by Miller, Green, and Schermer (1984) and by Repp and Liberman (1984) that these different effects may have different sources. In particular, Miller et al suggest that lexical effects and semantic and syntactic influences on the one hand may be due to a different mechanism than influences such as speech rate and coarticulatory influences due to local phonetic context.…”