Publications

Abstract

Words are often pronounced with fewer segments in casual conversations than in formal speech. Previous research has shown that foreign language learners and beginning second language learners experience problems processing reduced speech. We examined whether this also holds for advanced second language learners. We designed a dictation task in Dutch consisting of sentences spliced from casual conversations and an unreduced counterpart of this task, with the same sentences carefully articulated by the same speaker. Advanced second language learners of Dutch produced substantially more transcription errors for the reduced than for the unreduced sentences. These errors made the sentences incomprehensible or led to non-intended meanings. The learners often did not rely on the semantic and syntactic information in the sentence or on the subsegmental cues to overcome the reductions. Hence, advanced second language learners also appear to suffer from the reduced pronunciation variants of words that are abundant in everyday conversations

Abstract

This study investigates how the comprehension of casual speech in foreign languages is affected by the phonotactic constraints in the listener’s native language. Non-native listeners of English with different native languages heard short English phrases produced by native speakers of English or Spanish and they indicated whether these phrases included can or can’t. Native Mandarin listeners especially tended to interpret can’t as can. We interpret this result as a direct effect of the ban on word-final /nt/ in Mandarin. Both the native Mandarin and the native Spanish listeners did not take full advantage of the subsegmental information in the speech signal cueing reduced can’t. This finding is probably an indirect effect of the phonotactic constraints in their native languages: these listeners have difficulties interpreting the subsegmental cues because these cues do not occur or have different functions in their native languages. Dutch resembles English in the phonotactic constraints relevant to the comprehension of can’t, and native Dutch listeners showed similar patterns in their comprehension of native and non-native English to native English listeners. This result supports our conclusion that the major patterns in the comprehension results are driven by the phonotactic constraints in the listeners’ native languages.

Abstract

This paper investigates the processes in comprehending spoken noun-noun compounds, using data from the BALDEY database. BALDEY contains lexicality judgments and reaction times (RTs) for Dutch stimuli for which also linguistic information is included. Two different approaches are combined. The first is based on regression by Dynamic Survival Analysis, which models decisions and RTs as a consequence of the fact that a cumulative density function exceeds some threshold. The parameters of that function are estimated from the observed RT data. The second approach is based on DIANA, a process-oriented computational model of human word comprehension, which simulates the comprehension process with the acoustic stimulus as input. DIANA gives the identity and the number of the word candidates that are activated at each 10 ms time step.

Both approaches show how the processes involved in comprehending compounds change during a stimulus. Survival Analysis shows that the impact of word duration varies during the course of a stimulus. The density of word and non-word hypotheses in DIANA shows a corresponding pattern with different regimes. We show how the approaches complement each other, and discuss additional ways in which data and process models can be combined.

Abstract

Previous work has shown that novel morphologically complex words (henceforth neologisms) leave traces in memory after just one encounter. This study addressed the question whether these traces are abstract in nature or exemplars. In three experiments, neologisms were either primed by themselves or by their stems. The primes occurred in the visual modality whereas the targets were presented in the auditory modality (Experiment 1) or vice versa (Experiments 2 and 3). The primes were presented in sentences in a selfpaced reading task (Experiment 1) or in stories in a listening comprehension task (Experiments 2 and 3). The targets were incorporated in lexical decision tasks, auditory or visual (Experiment 1 and Experiment 2, respectively), or in stories in a self-paced reading task (Experiment 3). The experimental part containing the targets immediately followed the familiarization phase with the primes (Experiment 1), or after a one week delay (Experiments 2 and 3). In all experiments, participants recognized neologisms faster if they had encountered them before (identity priming) than if the familiarization phase only contained the neologisms’ stems (stem priming). These results show that the priming effects are robust despite substantial differences between the primes and the targets. This suggests that the traces novel morphologically complex words leave in memory after just one encounter are abstract in nature.

Abstract

This electrophysiological study asked whether the brain processes grammatical gender
violations in casual speech differently than in careful speech. Native speakers of Dutch were
presented with utterances that contained adjective-noun pairs in which the adjective was either
correctly inflected with a word-final schwa (e.g. een spannende roman “a suspenseful novel”) or
incorrectly uninflected without that schwa (een spannend roman). Consistent with previous
findings, the uninflected adjectives elicited an electrical brain response sensitive to syntactic
violations when the talker was speaking in a careful manner. When the talker was speaking in a
casual manner, this response was absent. A control condition showed electrophysiological responses
for carefully as well as casually produced utterances with semantic anomalies, showing that
listeners were able to understand the content of both types of utterance. The results suggest that
listeners take information about the speaking style of a talker into account when processing the
acoustic-phonetic information provided by the speech signal. Absent schwas in casual speech are
effectively not grammatical gender violations. These changes in syntactic processing are evidence
of contextually-driven neural flexibility.

Abstract

This study addresses the extent to which the location of primary stress in Dutch, German, and English monomorphemic words is affected by the syllables preceding the three final syllables. We present analyses of the monomorphemic words in the CELEX lexical database, which showed that penultimate primary stress is less frequent in Dutch and English trisyllabic than quadrisyllabic words. In addition, we discuss paper-and-pencil experiments in which native speakers assigned primary stress to pseudowords. These experiments provided evidence that in all three languages penultimate stress is more likely in quadrisyllabic than in trisyllabic words. We explain this length effect with the preferences in these languages for word-initial stress and for alternating patterns of stressed and unstressed syllables. The experimental data also showed important intra- and interspeaker variation, and they thus form a challenging test case for theories of language variation.

Abstract

This paper explores the relationship between the acoustic duration of phonemic sequences and their frequencies of occurrence. The data were obtained from large (sub)corpora of spontaneous speech in Dutch, English, German, and Italian. Acoustic duration of an n-phone is shown to codetermine the n-phone's frequency of use, such that languages preferentially use diphones and triphones that are neither very long nor very short. The observed distributions are well approximated by a theoretical function that quantifies the concurrent action of the self-regulatory processes of minimization of articulatory effort and minimization of perception effort

Abstract

This study reports a shadowing experiment, in which one has to repeat a speech stimulus as fast as possible. We tested claims about a direct link between perception and production based on speech gestures, and obtained two types of counterevidence. First, shadowing is not slowed down by a gestural mismatch between stimulus and response. Second, phonetic detail is more likely to be imitated in a shadowing task if it is phonologically relevant. This is consistent with the idea that speech perception and speech production are only loosely coupled, on an abstract phonological level.

Abstract

In four experiments, we investigated how listeners compensate for reduced /t/ in Dutch. Mitterer and Ernestus [Mitterer,H., & Ernestus, M. (2006). Listeners recover /t/s that speakers lenite: evidence from /t/-lenition in Dutch. Journal of Phonetics, 34, 73–103] showed that listeners are biased to perceive a /t/ more easily after /s/ than after /n/, compensating for the tendency of speakers to reduce word-final /t/ after /s/ in spontaneous conversations. We tested the robustness of this phonological context effect in perception with three very different experimental tasks: an identification task, a discrimination task with native listeners and with non-native listeners who do not have any experience with /t/-reduction,and a passive listening task (using electrophysiological dependent measures). The context effect was generally robust against these experimental manipulations, although we also observed some deviations from the overall pattern. Our combined results show that the context effect in compensation for reduced /t/ results from a complex process involving auditory constraints, phonological learning, and lexical constraints.

Abstract

This study investigates the roles of phonetic analogy and lexical frequency in an ongoing sound change, the devoicing of fricatives in Dutch, which occurs mainly in the Netherlands and to a lesser degree in Flanders. In the experiment, Dutch and Flemish students read two variants of 98 words: the standard and a nonstandard form with the incorrect voice value of the fricative. Dutch students chose the non-standard forms with devoiced fricatives more often than Flemish students. Moreover, devoicing, though a gradual process, appeared lexically diffused, affecting first the words that are low in frequency and phonetically similar to words with voiceless fricatives.

Abstract

This paper presents the steps needed to make a corpus of Dutch spontaneous dialogues accessible for automatic phonetic research aimed at increasing our understanding of reduction phenomena and the role of fine phonetic detail. Since the corpus was not created with automatic processing in mind, it needed to be reshaped. The first part of this paper describes the actions needed for this reshaping in some detail. The second part reports the results of a preliminary analysis of the reduction phenomena in the corpus. For this purpose a phonemic transcription of the corpus was created by means of a forced alignment, first with a lexicon of canonical pronunciations and then with multiple pronunciation variants per word. In this study pronunciation variants were generated by applying a large set of phonetic processes that have been implicated in reduction to the canonical pronunciations of the words. This relatively straightforward procedure allows us to produce plausible pronunciation variants and to verify and extend the results of previous reduction studies reported in the literature.

Abstract

This study reports general and language-specific patterns in phoneme identification. In a series of phoneme monitoring experiments, Castilian Spanish, Catalan, Dutch, English, and Polish listeners identified vowel, fricative, and stop consonant targets that are phonemic in all these languages, embedded in nonsense words. Fricatives were generally identified more slowly than vowels, while the speed of identification for stop consonants was highly dependent on the onset of the measurements. Moreover, listeners' response latencies and accuracy in detecting a phoneme correlated with the number of categories within that phoneme's class in the listener's native phoneme repertoire: more native categories slowed listeners down and decreased their accuracy. We excluded the possibility that this effect stems from differences in the frequencies of occurrence of the phonemes in the different languages. Rather, the effect of the number of categories can be explained by general properties of the perception system, which cause language-specific patterns in speech processing.

Abstract

The main goal of the present study is to trace the consequences of local and global markedness for the processing of singular and plural nouns. Decompositional models such as proposed by (Pinker (1997); Pinker (1999)) and (Levelt et al. (1999)) predict a lexeme frequency effect and no effects of the frequencies of the singular and the plural forms. Experiments 1 and 4 reveal the expected lexeme frequency effect. Furthermore, in these experiments there are no clear independent effects of the frequencies of the inflected forms. However, the effects of Entropy and Relative Entropy that emerge from these experiments show that in production knowledge of the probabilities of the individual inflected forms do play a role, albeit indirectly. These entropy effects bear witness to the importance of paradigmatic organization of inflected forms in the mental lexicon, both at the level of individual lexemes (Entropy) and at the general level of the class of nouns (Relative Entropy).

Abstract

This article shows that Old-French literary texts differ systematically in their relative frequencies of syntactic constructions. These frequencies reflect differences in register (poetry versus prose), region (Picardy, Champagne, and Esatern France), time period (until 1250, 1251 – 1300, 1301 – 1350), and genre (hagiography, romance of chivalry, or other).

Abstract

Two lexical decision experiments addressed the role of paradigmatic effects in auditory word recognition. Experiment 1 showed that listeners classified a form with an incorrectly voiced final obstruent more readily as a word if the obstruent is realised as voiced in other forms of that word's morphological paradigm. Moreover, if such was the case, the exact probability of paradigmatic voicing emerged as a significant predictor of the response latencies. A greater probability of voicing correlated with longer response latencies for words correctly realised with voiceless final obstruents. A similar effect of this probability was observed in Experiment 2 for words with completely voiceless or weakly voiced (incompletely neutralised) final obstruents. These data demonstrate the relevance of paradigmatically related complex words for the processing of morphologically simple words in auditory word recognition.

Abstract

This study addresses the roles of segment deletion, durational reduction, and frequency of use in the comprehension of morphologically complex words. We report two auditory lexical decision experiments with reduced and unreduced prefixed Dutch words. We found that segment deletions as such delayed comprehension. Simultaneously, however, longer durations of the different parts of the words appeared to increase lexical competition, either from the word’s stem (Experiment 1) or from the word’s morphological continuation forms (Experiment 2). Increased lexical competition slowed down especially the comprehension of low frequency words, which shows that speakers do not try to meet listeners’ needs when they reduce especially high frequency words.

Abstract

In Dutch, all morpheme-final obstruents are voiceless in word-final position. As a consequence, the distinction between obstruents that are voiced before vowel-initial suffixes and those that are always voiceless is neutralized. This study adds to the existing evidence that the neutralization is incomplete: neutralized, alternating plosives tend to have shorter bursts than non-alternating plosives. Furthermore, in a rating study, listeners scored the alternating plosives as more voiced than the nonalternating plosives, showing sensitivity to the subtle subphonemic cues in the acoustic signal. Importantly, the participants who were presented with the complete words, instead of just the final rhymes, scored the alternating plosives as even more voiced. This shows that listeners’ perception of voice is affected by their knowledge of the obstruent’s realization in the word’s morphological paradigm. Apparently, subphonemic paradigmatic levelling is a characteristic of both production and perception. We explain the effects within an analogy-based approach.

Abstract

This study explores the effects of informational redundancy, as carried by a word's morphological paradigmatic structure, on acoustic duration in read aloud speech. The hypothesis that the more predictable a linguistic unit is, the less salient its realization, was tested on the basis of the acoustic duration of interfixes in Dutch compounds in two datasets: One for the interfix -s- (1155 tokens) and one for the interfix -e(n)- (742 tokens). Both datasets show that the more probable the interfix is, given the compound and its constituents, the longer it is realized. These findings run counter to the predictions of information-theoretical approaches and can be resolved by the Paradigmatic Signal Enhancement Hypothesis. This hypothesis argues that whenever selection of an element from alternatives is probabilistic, the element's duration is predicted by the amount of paradigmatic support for the element: The most likely alternative in the paradigm of selection is realized longer.

Abstract

The present study investigates the influence of prosodic structure on the fine-grained phonetic details of German plosives which also cue the phonological fortis-lenis contrast. Closure durations were found to be longer at higher prosodic boundaries. There was also less glottal vibration in lenis plosives at higher prosodic boundaries. Voice onset time in lenis plosives was not affected by prosody. In contrast, for the fortis plosives VOT decreased at higher boundaries, as did the maximal intensity of the release. These results demonstrate that the effects of prosody on different phonetic cues can go into opposite directions, but are overall constrained by the need to maintain phonological contrasts. While prosodic effects on some cues are compatible with a ‘fortition’ account of prosodic strengthening or with a general feature enhancement explanation, the effects on others enhance paradigmatic contrasts only within a given prosodic position.

Abstract

This study addressed prosodic effects on the duration of and amount of glottal vibration in German word-initial fricatives /f, v, z/ in assimilatory and non-assimilatory devoicing contexts. Fricatives following /small schwa/ (non-assimilation context) were longer and were produced with less glottal vibration after higher prosodic boundaries, reflecting domain-initial prosodic strengthening. After /t/ (assimilation context), lenis fricatives (/v, z/) were produced with less glottal vibration than after /small schwa/, due to assimilatory devoicing. This devoicing was especially strong across lower prosodic boundaries, showing the influence of prosodic structure on sandhi processes. Reduction in glottal vibration made lenis fricatives more fortis-like (/f, s/). Importantly, fricative duration, another major cue to the fortis-lenis distinction, was affected by initial lengthening, but not by assimilation. Hence, at smaller boundaries, fricatives were more devoiced (more fortis-like), but also shorter (more lenis-like). As a consequence, the fortis and lenis fricatives remained acoustically distinct in all prosodic and segmental contexts. Overall, /z/ was devoiced to a greater extent than /v/. Since /z/ does not have a fortis counterpart in word-initial position, these findings suggest that phonotactic restrictions constrain phonetic processes. The present study illuminates a complex interaction of prosody, sandhi processes, and phonotactics, yielding systematic phonetic cues to prosodic structure and phonological distinctions.

Abstract

The difficulty of the task of segmenting a speech signal into its words is immediately clear when listening to a foreign language; it is much harder to segment the signal into its words, since the words of the language are unknown. Infants are faced with the same task when learning their first language. This study provides a better understanding of the task that infants face while learning their native language. We employed an automatic algorithm on the task of speech segmentation without prior knowledge of the labels of the phonemes. An analysis of the boundaries erroneously placed inside a phoneme showed that the algorithm consistently placed additional boundaries in phonemes in which acoustic changes occur. These acoustic changes may be as great as the transition from the closure to the burst of a plosive or as subtle as the formant transitions in low or back vowels. Moreover, we found that glottal vibration may attenuate the relevance of acoustic changes within obstruents. An interesting question for further research is how infants learn to overcome the natural tendency to segment these ‘dynamic’ phonemes.