Comprehension Dept Publications

Abstract

This study investigates the prosodic conditioning of phonetic details which are candidate cues to phonological contrasts. German /b, d, g, p, t, k/ were examined in three prosodic positions. Lenis plosives /b, d, g/ were produced with less glottal vibration at larger prosodic boundaries, whereas their VOT showed no effect of prosody. VOT of fortis plosives /p, t, k/ decreased at larger boundaries, as did their burst intensity maximum. Vowels (when measured from consonantal release) following fortis plosives and lenis velars were shorter after larger boundaries. Closure duration, which did not contribute to the fortis/lenis contrast, was heavily affected by prosody. These results support neither of the hitherto proposed accounts of prosodic strengthening (Uniform Strengthening and Feature Enhancement). We propose a different account, stating that the phonological identity of speech sounds remains stable not only within, but also across prosodic positions (contrast-over-prosody hypothesis). Domain-initial strengthening hardly diminishes the contrast between prosodically weak fortis and strong lenis plosives.

Abstract

A corpus of Dutch falling-rising intonation contours with early nuclear accent was elicited from nine speakers with a view to establishing the extent to which the low F0 target immediately preceding the final rise, was attracted by a post-nuclear stressed syllable (PNS) in either of the last two words or by Second Occurrence Contrastive Focus (SOCF) on either of these words. We found a small effect of foot type, which we interpret as due to a rhythmic 'trochaic enhancement' effect. The results show that neither PNS nor SOCF influences the location of the low F0 target, which appears consistently to be timed with reference to the utterance end. It is speculated that there are two ways in which postnuclear tones can be timed. The first is by means of a phonological association with a post-nuclear stressed syllable, as in Athenian Greek and Roermond Dutch. The second is by a fixed distance from the utterance end or from the target of an adjacent tone. Accordingly, two phonological mechanisms are defended, association and edge alignment, such that all tones edge-align, but only some associate. Specifically, no evidence was found for a third situation that can be envisaged, in which a post-nuclear tone is gradiently attracted to a post-nuclear stress.

Abstract

We investigated whether seeing a pointing gesture influences the perceived lexical stress. A pitch contour continuum between the Dutch words “CAnon” (‘canon’) and “kaNON” (‘cannon’) was presented along with a pointing gesture during the first or the second syllable. Pointing gestures following natural recordings but not Gaussian functions influenced stress perception (Experiment 1 and 2), especially when auditory context preceded (Experiment 2). This was not replicated in Experiment 3. Natural pointing gestures failed to affect the categorization of a pitch peak timing continuum (Experiment 4). There is thus no convincing evidence that seeing a pointing gesture influences lexical stress perception.

Abstract

This paper presents a method to quantify the spectral characteristics of reduction in speech. Hämäläinen et al. (2009) proposes a measure of spectral reduction which is able to predict a substantial amount of the variation in duration that linguistically motivated variables do not account for. In this paper, we continue studying acoustic reduction in speech by developing a new acoustic measure of reduction, based on local manifold structure in speech. We show that this measure yields significantly improved statistical models for predicting variation in duration.

Abstract

Recognizing phonetically reduced forms is a huge challenge for spoken-word recognition. Phonetic reductions not only occur often, but also come in a variety of forms. The paper investigates how two similar forms of reductions – /t/-reduction and nasal place assimilation in Dutch – can eventually be recognized, focusing on the role of following phonological context. Previous research indicated that listeners take the following phonological context into account when compensating for /t/-reduction and nasal place assimilation. The current paper shows that these context effects arise in early perceptual processes for the perception of assimilated forms, but at a later stage of processing for the perception of /t/-reduced forms. This shows first that the recognition of apparently similarly reduced words may rely on different processing mechanisms and, second, that searching for dissociations over tasks is a promising research strategy to investigate how reduced forms are recognized.

Abstract

The present study addresses the question whether accentuation and prosodic phrasing can have a similar function, namely, to group words in a sentence together. Participants listened to locally ambiguous sentences containing object- and subject-control verbs while ERPs were measured. In Experiment 1, these sentences contained a prosodic break, which can create a certain syntactic grouping of words, or no prosodic break. At the disambiguation, an N400 effect occurred when the disambiguation was in conflict with the syntactic grouping created by the break. We found a similar N400 effect without the break, indicating that the break did not strengthen an already existing preference. This pattern held for both object- and subject-control items. In Experiment 2, the same sentences contained a break and a pitch accent on the noun following the break. We argue that the pitch accent indicates a broad focus covering two words [see Gussenhoven, C. On the limits of focus projection in English. In P. Bosch & R. van der Sandt (Eds.), Focus: Linguistic, cognitive, and computational perspectives. Cambridge: University Press, 1999], thus grouping these words together. For object-control items, this was semantically possible, which led to a “good-enough” interpretation of the sentence. Therefore, both sentences were interpreted equally well and the N400 effect found in Experiment 1 was absent. In contrast, for subject-control items, a corresponding grouping of the words was impossible, both semantically and syntactically, leading to processing difficulty in the form of an N400 effect and a late positivity. In conclusion, accentuation can group words together on the level of information structure, leading to either a semantically “good-enough” interpretation or a processing problem when such a semantic interpretation is not possible.

Abstract

Listeners tune in to talkers’ vowels through extrinsic normalization. We asked here whether this process could be based on compensation for the Long Term Average Spectrum (LTAS) of preceding sounds and whether the mechanisms responsible for normalization are indifferent to the nature of those sounds. If so, normalization should apply to nonspeech stimuli. Previous findings were replicated with first formant (F1) manipulations of speech. Targets on a [pIt]-[pEt] (low-high F1) continuum were labeled as [pIt] more after high-F1 than after low-F1 precursors. Spectrally-rotated nonspeech versions of these materials produced similar normalization. None occurred, however, with nonspeech stimuli that were less speech-like, even though precursor-target LTAS relations were equivalent to those used earlier. Additional experiments investigated the roles of pitch movement, amplitude variation, formant location, and the stimuli's perceived similarity to speech. It appears that normalization is not restricted to speech, but that the nature of the preceding sounds does matter. Extrinsic normalization of vowels is due at least in part to an auditory process which may require familiarity with the spectro-temporal characteristics of speech.

Abstract

Two experiments examined whether perceptual recovery from Korean consonant-cluster simplification is based on language-specific phonological knowledge. In tri-consonantal C1C2C3 sequences such as /lkt/ and /lpt/ in Seoul Korean, either C1 or C2 can be completely deleted. Seoul Koreans monitored for C2 targets (/p/ or / k/, deleted or preserved) in the second word of a two-word phrase with an underlying /l/-C2-/t/ sequence. In Experiment 1 the target-bearing words had contextual lexical-semantic support. Listeners recovered deleted targets as fast and as accurately as preserved targets with both Word and Intonational Phrase (IP) boundaries between the two words. In Experiment 2, contexts were low-pass filtered. Listeners were still able to recover deleted targets as well as preserved targets in IP-boundary contexts, but better with physically-present targets than with deleted targets in Word-boundary contexts. This suggests that the benefit of having target acoustic-phonetic information emerges only when higher-order (contextual and phrase-boundary) information is not available. The strikingly efficient recovery of deleted phonemes with neither acoustic-phonetic cues nor contextual support demonstrates that language-specific phonological knowledge, rather than language-universal perceptual processes which rely on fine-grained phonetic details, is employed when the listener perceives the results of a continuous-speech process in which reduction is phonetically complete.

Abstract

Speakers tend to take over the articulatory habits of their interlocutors [e.g., Pardo, JASA (2006)]. This phonetic alignment could be the consequence of either a social mechanism or a direct and automatic link between speech perception and production. The latter assumes that social variables should have little influence on phonetic alignment. To test that participants were engaged in a "cloze task" (i.e., Stimulus: "In fantasy movies, silver bullets are used to kill ..." Response: "werewolves") with either one or four interlocutors. Given findings with the Asch-conformity paradigm in social psychology, multiple consistent speakers should exert a stronger force on the participant to align. To control the speech style of the interlocutors, their questions and answers were pre-recorded in either a formal or a casual speech style. The stimuli's speech style was then manipulated between participants and was consistent throughout the experiment for a given participant. Surprisingly, participants aligned less with the speech style if there were multiple interlocutors. This may reflect a "diffusion of responsibility:" Participants may find it more important to align when they interact with only one person than with a larger group.

Abstract

In the visual world paradigm as used in psycholinguistics, eye gaze (i.e. visual orienting) is measured in order to draw conclusions about linguistic processing. However, current theories are underspecified with respect to how visual attention is guided on the basis of linguistic representations. In the visual search paradigm as used within the area of visual attention research, investigators have become more and more interested in how visual orienting is affected by higher order representations, such as those involved in memory and language. Within this area more specific models of orienting on the basis of visual information exist, but they need to be extended with mechanisms that allow for language-mediated orienting. In the present paper we review the evidence from these two different – but highly related – research areas. We arrive at a model in which working memory serves as the nexus in which long-term visual as well as linguistic representations (i.e. types) are bound to specific locations (i.e. tokens or indices). The model predicts that the interaction between language and visual attention is subject to a number of conditions, such as the presence of the guiding representation in working memory, capacity limitations, and cognitive control mechanisms.

Abstract

This study investigates the lifespans of lexical traces for novel morphologically complex words. In two visual lexical decision experiments, a neologism was either primed by itself or by its stem. The target occurred 40 trials after the prime (Experiments 1 & 2), after a 12 hour delay (Experiment 1), or after a one week delay (Experiment 2). Participants recognized neologisms more quickly if they had seen them before in the experiment. These results show that memory traces for novel morphologically complex words already come into existence after a very first exposure and that they last for at least a week. We did not find evidence for a role of sleep in the formation of memory traces. Interestingly, Base Frequency appeared to play a role in the processing of the neologisms also when they were presented a second time and had their own memory traces.

Abstract

This study presents an analysis of over 4000 tokens of words produced as variants with and without schwa in a French corpus of radio-broadcasted speech. In order to determine which of the many variables mentioned in the literature influence variant choice, 17 predictors were tested in the same analysis. Only five of these variables appeared to condition variant choice. The question of the processing stage, or locus, of this alternation process is also addressed in a comparison of the variables that predict variant choice with the variables that predict the acoustic duration of schwa in variants with schwa. Only two variables predicting variant choice also predict schwa duration. The limited overlap between the predictors for variant choice and for schwa duration, combined with the nature of these variables, suggest that the variants without schwa do not result from a phonetic process of reduction; that is, they are not the endpoint of gradient schwa shortening. Rather, these variants are generated early in the production process, either during phonological encoding or word-form retrieval. These results, based on naturally produced speech, provide a useful complement to on-line production experiments using artificial speech tasks.

Abstract

The nature of children’s early lexical processing was investigated by asking what information 36-month-olds access and use when instructed to find a known but absent referent. Children readily retrieved stored knowledge about characteristic color, i.e. when asked to find an object with a typical color (e.g. strawberry), children tended to fixate more upon an object that had the same (e.g. red plane) as opposed to a different (e.g. yellow plane) color. They did so regardless of the fact that they have had plenty of time to recognize the pictures for what they are, i.e. planes not strawberries. These data represent the first demonstration that language-mediated shifts of overt attention in young children can be driven by individual stored visual attributes of known words that mismatch on most other dimensions. The finding suggests that lexical processing and overt attention are strongly linked from an early age.

Abstract

Despite their relatedness, Dutch and German differ in the interpretation of a particular intonation contour, the hat pattern. In the literature, this contour has been described as neutral for Dutch, and as contrastive for German. A recent study supports the idea that Dutch listeners interpret this contour neutrally, compared to the contrastive interpretation of a lexically identical utterance realised with a double peak pattern. In particular, this study showed shorter lexical decision latencies to visual targets (e.g., PELIKAAN, “pelican”) following a contrastively related prime (e.g., flamingo, “flamingo”) only when the primes were embedded in sentences with a contrastive double peak contour, not in sentences with a neutral hat pattern. The present study replicates Experiment 1a of Braun and Tagliapietra (2009) with German learners of Dutch. Highly proficient learners of Dutch differed from Dutch natives in that they showed reliable priming effects for both intonation contours. Thus, the interpretation of intonational meaning in L2 appears to be fast, automatic, and driven by the associations learned in the native language.

Abstract

In everyday speech, words are often produced with reduced pronunciation variants, in which segments are shorter or completely absent. We investigated whether word-final /t/ reduction in Dutch past-participles is affected by the ease of planning of the preceding word, and whether previously found morphological effects may actually be planning effects. We analyzed presence of 1369 /t/s and their durations in two speech corpora representing three speech styles. /t/ appeared more often absent and shorter if the past-participle followed a word that is highly predictable given the preceding context. Furthermore, /t/ was more reduced in irregular pastparticiples with a high frequency relative to the frequencies of the other inflected forms in the verbal paradigm, that is, in past-participles that can be selected more easily, and thus planned more quickly. Both effects were more pronounced in more spontaneous speech styles, which is as expected if the effects are driven by speech planning. These planning effects have to be incorporated in psycholinguistic models of speech production. Abstractionist models could, for instance, adapt the articulation level. Exemplar-based models have to incorporate planning as a factor influencing the choice of exemplar, or assume an articulation level that can modify the selected exemplar.

Abstract

Listeners can flexibly retune category boundaries of their native language to adapt to non-canonically produced phonemes. This only occurs, however, if the pronunciation peculiarities can be attributed to stable and not transient speaker-specific characteristics. Listening to someone speaking a second language, listeners could attribute non-canonical pronunciations either to the speaker or to the fact that she is modifying her categories in the second language. We investigated whether, following exposure to Dutch-accented English, Dutch listeners show effects of category retuning during test where they hear the same speaker speaking her native language, Dutch. Exposure was a lexical-decision task where either word-final [f] or [s] was replaced by an ambiguous sound. At test listeners categorized minimal word pairs ending in sounds along an [f]-[s] continuum. Following exposure to English words, Dutch listeners showed boundary shifts of a similar magnitude as following exposure to the same phoneme variants in their native language. This suggests that production patterns in a second language are deemed a stable characteristic. A second experiment suggests that category retuning also occurs when listeners are exposed to and tested with a native speaker of their second language. Listeners thus retune phoneme boundaries across languages.

Abstract

Listeners use lexical knowledge to adjust to speakers’ idiosyncratic pronunciations. Dutch listeners learn to interpret an ambiguous sound between /s/ and /f/ as /f/ if they hear it word-finally in Dutch words normally ending in /f/, but as /s/ if they hear it in normally /s/-final words. Here, we examined two positional effects in lexically guided retuning. In Experiment 1, ambiguous sounds during exposure always appeared in word-initial position (replacing the first sounds of /f/- or /s/-initial words). No retuning was found. In Experiment 2, the same ambiguous sounds always appeared word-finally during exposure. Here, retuning was found. Lexically guided perceptual learning thus appears to emerge reliably only when lexical knowledge is available as the to-be-tuned segment is initially being processed. Under these conditions, however, lexically guided retuning was position independent: It generalized across syllabic positions. Lexical retuning can thus benefit future recognition of particular sounds wherever they appear in words.