[Show abstract][Hide abstract] ABSTRACT: Recent evidence shows that studies on perceptual recalibration and its generalization can inform us about the presence and nature of prelexical units used for speech perception. Listeners recalibrate perception when hearing an ambiguous auditory stimulus between, for example, /p/ and /t/ in unambiguous lexical context (kee[p/t]->/p/, mee[p/t]->/t/) or visual context (presence vs. absence of lip closure). A later encountered ambiguous auditory-only stimulus is then perceived in line with the previously experienced context. Unlike studies using lexical context to guide learning, experiments with the visual paradigm suggested that prelexical units are rather specific and context-dependent. However, these experiments raised doubts whether lexically-guided and visually-guided recalibration are targeting the same type of units, or whether learning in the visually-guided paradigm—with limited variability during exposure—is task-specific. The present study shows successful visually-guided learning following exposure to a variety of different learning trials. We also show that patterns of generalization found with the visually-guided paradigm can be replicated with a lexically-guided paradigm: listeners do not generalize a recalibrated stop contrast across manner of articulation. This supports suggestions that the units of perception depend on the distribution of relevant cues in the speech signal.
Full-text · Article · Mar 2016 · Journal of Phonetics
[Show abstract][Hide abstract] ABSTRACT: To deal with variation in the speech signal, listeners rely on local context, such as speaking rate in a carrier sentence directly preceding a target, as well as more global properties of the speech signal, such as speaker-specific pronunciation variants. The present study addressed whether, despite its variability even within one speaker, habitual speaking rate can be tracked as a speaker-specific property and how such speaker-specific tracking of habitual rate would interact with effects of local-rate normalization. In two experiments, listeners were exposed to a 2-min dialogue between a fast and a slow speaker. At test, listeners categorized minimal word pair continua differing in the German /a/–/a:/ duration contrast spoken by the same two speakers. The results showed that listeners responded with /a:/ more often for the fast speaker but only when words were presented in isolation and not when presented with additional local-rate information. That is, despite the general assumption that duration cues and speaking rate are too variable to be used in a speaker-specific fashion, tracking habitual speaking rate may help speech perception. The results are discussed in relation to a belief-updating model of perceptual adaptation and exemplar models.
No preview · Article · Dec 2015 · Applied Psycholinguistics
[Show abstract][Hide abstract] ABSTRACT: It has been claimed that learning to read changes the way we perceive speech, with detrimental effects for words with sound-spelling inconsistencies. Because conversational speech is peppered with segment deletions and alterations that lead to sound-spelling inconsistencies, such an influence would seriously hinder the perception of conversational speech. We hence tested whether the orthographic coding of a segment influences its deletion costs in perception. German glottal stop, a segment that is canonically present but not orthographically coded, allows such a test. The effects of glottal-stop deletion in German were compared to deletion of /h/ in German (grapheme: h) and deletion of glottal stop in Maltese (grapheme: q) in an implicit task with conversational speech and explicit task with careful speech. All segment deletions led to similar reduction costs in the implicit task, while an orthographic effect, with larger effects for orthographically coded segments, emerged in the explicit task. These results suggest that learning to read does not influence how we process speech but mainly how we think about it.
Full-text · Article · Sep 2015 · Journal of Memory and Language
[Show abstract][Hide abstract] ABSTRACT: Listeners have to overcome variability of the speech signal that can arise, for example, because of differences in room acoustics, differences in speakers' vocal tract properties, or idiosyncrasies in pronunciation. Two mechanisms that are involved in resolving such variation are perceptually contrastive effects that arise from surrounding acoustic context and lexically guided perceptual learning. Although both processes have been studied in great detail, little attention has been paid to how they operate relative to each other in speech perception. The present study set out to address this issue. The carrier parts of exposure stimuli of a classical perceptual learning experiment were spectrally filtered such that the acoustically ambiguous final fricatives sounded relatively more like the lexically intended sound (Experiment 1) or the alternative (Experiment 2). Perceptual learning was found only in the latter case. The findings show that perceptual contrast effects precede lexically guided perceptual learning, at least in terms of temporal order, and potentially in terms of cognitive processing levels as well. (PsycINFO Database Record
(c) 2015 APA, all rights reserved).
Full-text · Article · Mar 2015 · Journal of Experimental Psychology Human Perception & Performance
[Show abstract][Hide abstract] ABSTRACT: Based on the theoretical framework of Dressler and Dziubalska-Kołaczyk (2006a,b), the Strong Morphonotactic Hypothesis will be tested. It assumes that phonotactics helps in decomposition of words into morphemes: if a certain sequence occurs only or only by default over a morpheme boundary and is thus a prototypical morphonotactic sequence, it should be processed faster and more accurately than a purely phonotactic sequence. Studies on typical and atypical first language acquisition in English, Lithuanian and Polish have shown significant differences between the acquisition of morphonotactic and phonotactic consonant clusters: Morphonotactic clusters are acquired earlier and faster by typically developing children, but are more problematic for children with Specific Language Impairment. However, results on acquisition are less clear for German. The focus of this contribution is whether and how German-speaking adults differentiate between morphonotactic and phonotactic consonant clusters and vowel-consonant sequences in visual word recognition. It investigates whether sub-lexical letter sequences are found faster when the target sequence is separated from the word stem by a morphological boundary than when it is a part of a morphological root. An additional factor that is addressed concerns the position of the target cluster in the word. Due to the bathtub effect, sequences in peripheral positions in a word are more salient and thus facilitate processing more than word-internal positions. Moreover, for adults the primacy effect most favors word-initial position (whereas for young children the recency effect most favors word-final position). Our study discusses effects of phonotactic vs. morphonotactic cluster status and of position within the word.
Full-text · Article · Nov 2014 · Language Sciences
[Show abstract][Hide abstract] ABSTRACT: Listeners use lexical or visual context information to recalibrate auditory speech perception. After hearing an ambiguous auditory stimulus between /aba/ and /ada/ coupled with a clear visual stimulus (e.g., lip closure in /aba/), an ambiguous auditory-only stimulus is perceived in line with the previously seen visual stimulus. What remains unclear, however, is what exactly listeners are recalibrating: phonemes, phone sequences, or acoustic cues. To address this question we tested generalization of visually-guided auditory recalibration to (1) the same phoneme contrast cued differently (i.e., /aba/-/ada/ vs. /ibi/-/idi/ where the main cues are formant transitions in the vowels vs. burst and frication of the obstruent), (2) a different phoneme contrast cued identically (/aba/-/ada/ vs. /ama/-/ana/ both cued by formant transitions in the vowels), and (3) the same phoneme contrast with the same cues in a different acoustic context (/aba/-/ada/ vs. /ubu/-/udu/). Whereas recalibration was robust for all recalibration control trials, no generalization was found in any of the experiments. This suggests that perceptual recalibration may be more specific than previously thought as it appears to be restricted to the phoneme category experienced during exposure as well as to the specific manipulated acoustic cues. We suggest that recalibration affects context-dependent sub-lexical units.
Full-text · Article · Jul 2014 · Journal of Phonetics
[Show abstract][Hide abstract] ABSTRACT: Three eye-tracking experiments tested at what processing stage lexically-guided retuning of a fricative contrast affects perception. One group of participants heard an ambiguous fricative between /s/ and /f/ replace /s/ in s-final words, the other group heard the same ambiguous fricative replacing /f/ in f-final words. In a test phase, both groups of participants heard a range of ambiguous fricatives at the end of Dutch minimal pairs (e.g., roos-roof, ‘rose’-‘robbery’). Participants who heard the ambiguous fricative replacing /f/ during exposure chose at test the f-final words more often than the other participants. During this test-phase, eye-tracking data showed that the effect of exposure exerted itself as soon as it could possibly have occurred, 200 ms after the onset of the fricative. This was at the same time as the onset of the effect of the fricative itself, showing that the perception of the fricative is changed by perceptual learning at an early level. Results converged in a time-window analysis and a Jackknife procedure testing the time at which effects reached a given proportion of their maxima. This indicates that perceptual learning affects early stages of speech processing, and supports the conclusion that perceptual learning is indeed perceptual rather than post-perceptual.
Full-text · Article · Nov 2013 · Journal of Memory and Language
[Show abstract][Hide abstract] ABSTRACT: Listeners use lexical knowledge to retune phoneme categories. When hearing an ambiguous sound between /s/ and /f/ in lexically unambiguous contexts such as gira[s/f], listeners learn to interpret the sound as /f/ because gira[f] is a real word and gira[s] is not. Later, they apply this learning even in lexically ambiguous contexts (perceiving knife rather than nice). Although such retuning could help listeners adapt to foreign-accented speech, research has focused on single phonetic contrasts artificially manipulated to create ambiguous sounds; however, accented speech varies along many dimensions. It is therefore unclear whether analogies to adaptation to accented speech are warranted. In the present studies, the to-be-adapted ambiguous sound was embedded in a global foreign accent. In addition, conditions of cross-speaker generalization were tested with focus on the extent to which perceptual similarity between 2 speakers' fricatives is a condition for generalization to occur. Results showed that listeners retune phoneme categories manipulated within the context of a global foreign accent, and that they generalize this short-term learning to the perception of phonemes from previously unheard speakers. However, generalization was observed only when exposure and test speakers' fricatives were sampled across a similar perceptual space. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Full-text · Article · Sep 2013 · Journal of Experimental Psychology Human Perception & Performance
[Show abstract][Hide abstract] ABSTRACT: Speech perception is dependent on auditory information within phonemes such as spectral or temporal cues. The perception of those cues, however, is affected by auditory information in surrounding context (e.g., a fast context sentence can make a target vowel sound subjectively longer). In a two-by-two design the current experiments investigated when these different factors influence vowel perception. Dutch listeners categorized minimal word pairs such as /tɑk/–/taːk/ (“branch”–“task”) embedded in a context sentence. Critically, the Dutch /ɑ/–/aː/ contrast is cued by spectral and temporal information. We varied the second formant (F2) frequencies and durations of the target vowels. Independently, we also varied the F2 and duration of all segments in the context sentence. The timecourse of cue uptake on the targets was measured in a printed-word eye-tracking paradigm. Results show that the uptake of spectral cues slightly precedes the uptake of temporal cues. Furthermore, acoustic manipulations of the context sentences influenced the uptake of cues in the target vowel immediately. That is, listeners did not need additional time to integrate spectral or temporal cues of a target sound with auditory information in the context. These findings argue for an early locus of contextual influences in speech perception.
Full-text · Article · Mar 2013 · Journal of Phonetics
[Show abstract][Hide abstract] ABSTRACT: Listeners adapt to non-canonically produced speech by using lexical knowledge to retune phoneme categories. It is unclear, however, whether these retuned categories affect perception at the category level or the signal-to-representation mapping. This was addressed by exploring conditions of cross-speaker generalization of retuned fricatives. During a lexical-decision task, American listeners heard a female Dutch learner of English whose word-final /f/ or /s/ was replaced by an ambiguous sound. At test listeners categorized minimal pairs ending in sounds along [f]-[s] continua spoken by the same female speaker and a new male speaker. Listeners' [f]-[s] categorization for the previously heard speaker shifted as a function of exposure. Generalization to the new speaker was not found when continua between his natural [f]-[s] endpoints were presented. However, listeners did generalize to this voice when presented with only a subset of the male's most [f]-like continuum steps, adjusting the fricative range to match the exposure speaker's, and eliminating a bias toward /s/-responses in the male continua. Listeners thus use short-term acquired knowledge about acoustic properties of phonemes even to interpret upcoming phonemes from previously unheard speakers. Acoustic match, not speaker identity, predicted the results supporting accounts of the effect originating in the early signal-to-representation mapping.
No preview · Article · Sep 2012 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: Phonetic categorization is influenced by multiple sources of contextual information, but little is known about how different sources of information interact. We examined the relative influence of lexical versus acoustic contexts on phonetic categorization of sounds along [s]-[S] continua embedded in word-nonword pairs (e.g., a[S]amed-a[s]amed, ca[s]ino-ca[S]ino). These categorization targets were preceded by sequences of 12 nonspeech tones with mean frequencies a standard deviation above or below the spectral means of the endpoint fricatives. Listeners' [s]-[S] categorization was influenced by lexical information, exhibiting a Ganong effect with categorization shifted toward responses consistent with words, and also by acoustic context. The effect of the tone sequence was spectrally contrastive; there were more [S] responses (low spectral mean) following higher-frequency tones and more [s] responses (high spectral mean) following lower-frequency tones. In addition, the influence of acoustic relative to lexical context was modulated by listening environment. When the informational load of the lexical context was low (four word-nonword continua) acoustic context exerted a relatively greater influence than when the informational load of the lexical context was high (forty word-nonword continua). Multiple sources of context interact to influence phonetic categorization and the relative influence of different information sources is flexibly modulated by listening environment.
No preview · Article · Sep 2012 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: Can native listeners rapidly adapt to suprasegmental mispronunciations in foreign-accented speech? To address this question, an exposure-test paradigm was used to test whether Dutch listeners can improve their understanding of non-canonical lexical stress in Hungarian-accented Dutch. During exposure, one group of listeners heard a Dutch story with only initially stressed words, whereas another group also heard 28 words with canonical second-syllable stress (e.g., EEKhorn, "squirrel" was replaced by koNIJN "rabbit"; capitals indicate stress). The 28 words, however, were non-canonically marked by the Hungarian speaker with high pitch and amplitude on the initial syllable, both of which are stress cues in Dutch. After exposure, listeners' eye movements were tracked to Dutch target-competitor pairs with segmental overlap but different stress patterns, while they listened to new words from the same Hungarian speaker (e.g., HERsens, herSTEL, "brain," "recovery"). Listeners who had previously heard non-canonically produced words distinguished target-competitor pairs better than listeners who had only been exposed to Hungarian accent with canonical forms of lexical stress. Even a short exposure thus allows listeners to tune into speaker-specific realizations of words' suprasegmental make-up, and use this information for word recognition.
Full-text · Article · Aug 2012 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: Native listeners adapt to noncanonically produced speech by retuning phoneme boundaries by means of lexical knowledge. We asked whether a second language lexicon can also guide category retuning and whether perceptual learning transfers from a second language (L2) to the native language (L1). During a Dutch lexical-decision task, German and Dutch listeners were exposed to unusual pronunciation variants in which word-final /f/ or /s/ was replaced by an ambiguous sound. At test, listeners categorized Dutch minimal word pairs ending in sounds along an /f/-/s/ continuum. Dutch L1 and German L2 listeners showed boundary shifts of a similar magnitude. Moreover, following exposure to Dutch-accented English, Dutch listeners also showed comparable effects of category retuning when they heard the same speaker speak her native language (Dutch) during the test. The former result suggests that lexical representations in a second language are specific enough to support lexically guided retuning, and the latter implies that production patterns in a second language are deemed a stable speaker characteristic likely to transfer to the native language; thus retuning of phoneme categories applies across languages. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Full-text · Article · Apr 2012 · Journal of Experimental Psychology Human Perception & Performance
[Show abstract][Hide abstract] ABSTRACT: A substantial tradition of linguistic inquiry has framed the knowledge of native speakers in terms of their ability to determine the grammatical acceptability of language forms that they encounter for the first time. In the domain of morphology, the productivity framework of Dressler (CLASNET Working papers 7, 1997) has emphasized the importance of this ability in terms of the graded potentiality of non-existing multimorphemic forms. The goal of this study was to investigate what role the notion of potentiality plays in online lexical well-formedness judgment among children who are native speakers of Austrian German. A total of 114 children between the ages of six and ten and a total of 40 adults between the ages of 18 and 30 (as a comparison group) participated in an online well-formedness judgment task which focused on pluralized German nouns. Concrete, picturable, high frequency German nouns were presented in three pluralized forms: (a) actual existing plural form, (b) morphologically illegal plural form, (c) potential (but not existing) plural form. Participants were shown pictures of the nouns (as a set of three identical items) and simultaneously heard one of three pluralized forms for each noun. Response latency and judgment type served as dependent variables. Results indicate that both children and adults are sensitive to the distinction between illegal and potential forms (neither of which they would have encountered). For all participants, plural frequency (rather than frequency of the singular form) affected responses for both existing and non-existing words. Other factors increasing acceptability were the presence of supplementary umlaut in addition to suffixation and homophony with existing words or word forms.
[Show abstract][Hide abstract] 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.
No preview · Article · Oct 2011 · The Journal of the Acoustical Society of America