This paper studies the robustness of exemplar effects in word comprehension by means of four long-term priming experiments with lexical decision tasks in Dutch. A prime and target represented the same word type and were presented with the same or different degree of reduction. In Experiment 1, participants heard only a small number of trials, a large proportion of repeated words, and stimuli produced by only one speaker. They recognized targets more quickly if these represented the same degree of reduction as their primes, which forms additional evidence for the exemplar effects reported in the literature. Similar effects were found for two speakers who differ in their pronunciations. In Experiment 2, with a smaller proportion of repeated words and more trials between prime and target, participants recognized targets preceded by primes with the same or a different degree of reduction equally quickly. Also, in Experiments 3 and 4, in which listeners were not exposed to one but two types of pronunciation variation (reduction degree and speaker voice), no exemplar effects arose. We conclude that the role of exemplars in speech comprehension during natural conversations, which typically involve several speakers and few repeated content words, may be smaller than previously assumed.Keywords: speech comprehension, exemplar effects, pronunciation variation, acoustic reduction 3 Several models of speech comprehension assume that the mental lexicon stores the pronunciation of a word with two types of representations, namely abstract representations and exemplars (e.g., Goldinger, 2007;McLennan, Luce, and Charles-Luce, 2003). Abstract representations are strings of sound symbols like phonemes or phonological features, which only contain information about acoustic properties that distinguish between these symbols. In contrast, clouds of exemplars represent many occurrences of words that the language user has uttered or heard. Each exemplar is a detailed representation corresponding to the speech signal of one occurrence and thus contains subtle acoustic information, for example about the word's exact pronunciation or the speaker's voice. Many articles in the literature point to a role of exemplars in word comprehension. This study investigates the robustness of these exemplar effects.Exemplar effects have been established in several priming experiments (e.g., Bradlow, Nygaard, and Pisoni, 1999;Craik and Kirsner, 1974;Goh, 2005;Goldinger, 1996;Janse, 2008;Mattys and Liss, 2008;McLennan et al., 2003;McLennan and Luce, 2005;Palmeri, Goldinger, and Pisoni, 1993).These experiments contained repeated words and the comprehension of the second occurrence of a word (the target) is expected to be facilitated by the first occurrence (the prime). Primes and targets were completely identical, that is the same token, or they differed in speech rate, time-compression, the realization of a certain segment (e.g., intervocalic /t,d/ produced as [t,d] or as a flap in American English), or the speaker's voice. Most experiments showed...

This paper studies the robustness of exemplar effects in word comprehension by means of four long-term priming experiments with lexical decision tasks in Dutch. A prime and target represented the same word type and were presented with the same or different degree of reduction. In Experiment 1, participants heard only a small number of trials, a large proportion of repeated words, and stimuli produced by only one speaker. They recognized targets more quickly if these represented the same degree of reduction as their primes, which forms additional evidence for the exemplar effects reported in the literature. Similar effects were found for two speakers who differ in their pronunciations. In Experiment 2, with a smaller proportion of repeated words and more trials between prime and target, participants recognized targets preceded by primes with the same or a different degree of reduction equally quickly. Also, in Experiments 3 and 4, in which listeners were not exposed to one but two types of pronunciation variation (reduction degree and speaker voice), no exemplar effects arose. We conclude that the role of exemplars in speech comprehension during natural conversations, which typically involve several speakers and few repeated content words, may be smaller than previously assumed.Keywords: speech comprehension, exemplar effects, pronunciation variation, acoustic reduction 3 Several models of speech comprehension assume that the mental lexicon stores the pronunciation of a word with two types of representations, namely abstract representations and exemplars (e.g., Goldinger, 2007;McLennan, Luce, and Charles-Luce, 2003). Abstract representations are strings of sound symbols like phonemes or phonological features, which only contain information about acoustic properties that distinguish between these symbols. In contrast, clouds of exemplars represent many occurrences of words that the language user has uttered or heard. Each exemplar is a detailed representation corresponding to the speech signal of one occurrence and thus contains subtle acoustic information, for example about the word's exact pronunciation or the speaker's voice. Many articles in the literature point to a role of exemplars in word comprehension. This study investigates the robustness of these exemplar effects.Exemplar effects have been established in several priming experiments (e.g., Bradlow, Nygaard, and Pisoni, 1999;Craik and Kirsner, 1974;Goh, 2005;Goldinger, 1996;Janse, 2008;Mattys and Liss, 2008;McLennan et al., 2003;McLennan and Luce, 2005;Palmeri, Goldinger, and Pisoni, 1993).These experiments contained repeated words and the comprehension of the second occurrence of a word (the target) is expected to be facilitated by the first occurrence (the prime). Primes and targets were completely identical, that is the same token, or they differed in speech rate, time-compression, the realization of a certain segment (e.g., intervocalic /t,d/ produced as [t,d] or as a flap in American English), or the speaker's voice. Most experiments showed...

This study focused on the realization of /p, t/ after schwa (e.g., support, certificate) in casual American English. We analyzed the realization of 523 tokens in the Buckeye corpus. Pronunciation variation proved substantial. Some plosives were realized as fricatives or were completely absent; others varied in the duration and voicing of the closure, burst presence, and voice onset time (VOT). Tokens of suppose(d) showed markedly more reduction than other words: schwa was more often absent (80% versus 28%) and VOT was much shorter (mean 19 ms versus 59 ms). We propose that suppose(d) has an additional lexical entry without schwa: spose(d). It is typically assumed that if the schwa is lost, a following voiceless plosive retains the long VOT that is typical in stressed syllable-initial position (e.g., support pronounced as [s’phort]). We compared VOT in our schwa words, excluding suppose(d), with that of 405 plosives occurring after /s/ (e.g., sport, still). Regression analyses showed that VOT was longer in syllable-initial position than after /s/ in consonant clusters (mean 16 ms). Schwa absence did not affect VOT and neither did the duration of schwa when present. This suggests that the reduction processes affecting vowels need not change the realization of consonants.

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