Publications

Abstract

Orthographies encode phonological information only at the level of words (chiefly, the information encoded concerns phonetic segments; in some cases, tonal information or default stress may be encoded). Of primary interest to second language (L2) learners is whether orthography can assist in clarifying L2 phonological distinctions that are particularly difficult to perceive (e.g., where one native-language phonemic category captures two L2 categories). A review of spoken-word recognition evidence suggests that orthographic information can install knowledge of such a distinction in lexical representations but that this does not affect learners’ ability to perceive the phonemic distinction in speech. Words containing the difficult phonemes become even harder for L2 listeners to recognize, because perception maps less accurately to lexical content.

Abstract

In an auditory lexical decision experiment, 5,541 spoken content words and pseudo-words were presented to 20 native speakers of Dutch. The words vary in phonological makeup and in number of syllables and stress pattern, and are further representative of the native Dutch vocabulary in that most are morphologically complex, comprising two stems or one stem plus derivational and inflectional suffixes, with inflections representing both regular and irregular paradigms; the pseudo-words were matched in these respects to the real words. The BALDEY data file includes response times and accuracy rates, with for each item morphological information plus phonological and acoustic information derived from automatic phonemic segmentation of the stimuli. Two initial analyses illustrate how this data set can be used. First, we discuss several measures of the point at which a word has no further neighbors, and compare the degree to which each measure predicts our lexical decision response outcomes. Second, we investigate how well four different measures of frequency of occurrence (from written corpora, spoken corpora, subtitles and frequency ratings by 70 participants) predict the same outcomes. These analyses motivate general conclusions about the auditory lexical decision task. The (publicly available) BALDEY database lends itself to many further analyses.

Abstract

Spoken-word recognition in a nonnative language is particularly difficult where it depends on discrimination between confusable phonemes. Four experiments here examine whether this difficulty is in part due to phantom competition from “near-words” in speech. Dutch listeners confuse English /aelig/ and /ε/, which could lead to the sequence daf being interpreted as deaf, or lemp being interpreted as lamp. In auditory lexical decision, Dutch listeners indeed accepted such near-words as real English words more often than English listeners did. In cross-modal priming, near-words extracted from word or phrase contexts (daf from DAFfodil, lemp from eviL EMPire) induced activation of corresponding real words (deaf; lamp) for Dutch, but again not for English, listeners. Finally, by the end of untruncated carrier words containing embedded words or near-words (definite; daffodil) no activation of the real embedded forms (deaf in definite) remained for English or Dutch listeners, but activation of embedded near-words (deaf in daffodil) did still remain, for Dutch listeners only. Misinterpretation of the initial vowel here favoured the phantom competitor and disfavoured the carrier (lexically represented as containing a different vowel). Thus, near-words compete for recognition and continue competing for longer than actually embedded words; nonnative listening indeed involves phantom competition.

Abstract

A visual fixation study tested whether seven-month-olds can discriminate between different talkers. The infants were first habituated to talkers producing sentences in either a familiar or unfamiliar language, then heard test sentences from previously unheard speakers, either in the language used for habituation, or in another language. When the language at test mismatched that in habituation, infants always noticed the change. When language remained constant and only talker altered, however, infants detected the change only if the language was the native tongue. Adult listeners with a different native tongue than the infants did not reproduce the discriminability patterns shown by the infants, and infants detected neither voice nor language changes in reversed speech; both these results argue against explanation of the native-language voice discrimination in terms of acoustic properties of the stimuli. The ability to identify talkers is, like many other perceptual abilities, strongly influenced by early life experience.

Abstract

Every language manifests casual speech processes, and hence every second language too. This study examined how listeners deal with second-language casual speech processes, as a function of the processes in their native language. We compared a match case, where a second-language process t/-reduction) is also operative in native speech, with a mismatch case, where a second-language process (/r/-insertion) is absent from native speech. In each case native and non-native listeners judged stimuli in which a given phoneme (in sentence context) varied along a continuum from absent to present. Second-language listeners in general mimicked native performance in the match case, but deviated significantly from native performance in the mismatch case. Together these results make it clear that the mapping from first to second language is as important in the interpretation of casual speech processes as in other dimensions of speech perception. Unfamiliar casual speech processes are difficult to adapt to in a second language. Casual speech processes that are already familiar from native speech, however, are easy to adapt to; indeed, our results even suggest that it is possible for subtle difference in their occurrence patterns across the two languages to be detected,and to be accommodated to in second-language listening

Abstract

In sequences such as law and order, speakers of British English often insert /r/ between law and and. Acoustic analyses revealed such “intrusive” /r/ to be significantly shorter than canonical /r/. In a 2AFC experiment, native listeners heard British English sentences in which /r/ duration was manipulated across a word boundary [e.g., saw (r)ice], and orthographic and semantic factors were varied. These listeners responded categorically on the basis of acoustic evidence for /r/ alone, reporting ice after short /r/s, rice after long /r/s; orthographic and semantic factors had no effect. Dutch listeners proficient in English who heard the same materials relied less on durational cues than the native listeners, and were affected by both orthography and semantic bias. American English listeners produced intermediate responses to the same materials, being sensitive to duration (less so than native, more so than Dutch listeners), and to orthography (less so than the Dutch), but insensitive to the semantic manipulation. Listeners from language communities without common use of intrusive /r/ may thus interpret intrusive /r/ as canonical /r/, with a language difference increasing this propensity more than a dialect difference. Native listeners, however, efficiently distinguish intrusive from canonical /r/ by exploiting the relevant acoustic variation.

Abstract

English listeners largely disregard suprasegmental cues to stress in recognizing words. Evidence for this includes the demonstration of Fear et al. [J. Acoust. Soc. Am. 97, 1893–1904 (1995)] that cross-splicings are tolerated between stressed and unstressed full vowels (e.g., au- of autumn, automata). Dutch listeners, however, do exploit suprasegmental stress cues in recognizing native-language words. In this study, Dutch listeners were presented with English materials from the study of Fear et al. Acceptability ratings by these listeners revealed sensitivity to suprasegmental mismatch, in particular, in replacements of unstressed full vowels by higher-stressed vowels, thus evincing greater sensitivity to prosodic goodness than had been shown by the original native listener group.

Abstract

Three experiments, in which Japanese listeners detected Japanese words embedded in nonsense sequences, examined the perceptual consequences of vowel devoicing in that language. Since vowelless sequences disrupt speech segmentation [Norris et al. (1997). Cognit. Psychol. 34, 191– 243], devoicing is potentially problematic for perception. Words in initial position in nonsense sequences were detected more easily when followed by a sequence containing a vowel than by a vowelless segment (with or without further context), and vowelless segments that were potential devoicing environments were no easier than those not allowing devoicing. Thus asa, “morning,” was easier in asau or asazu than in all of asap, asapdo, asaf, or asafte, despite the fact that the /f/ in the latter two is a possible realization of fu, with devoiced [u]. Japanese listeners thus do not treat devoicing contexts as if they always contain vowels. Words in final position in nonsense sequences, however, produced a different pattern: here, preceding vowelless contexts allowing devoicing impeded word detection less strongly (so, sake was detected less accurately, but not less rapidly, in nyaksake—possibly arising from nyakusake—than in nyagusake). This is consistent with listeners treating consonant sequences as potential realizations of parts of existing lexical candidates wherever possible.

Abstract

Recognizing word boundaries in continuous speech requires detailed knowledge of the native language. In the first year of life, infants acquire considerable word segmentation abilities. Infants at this early stage in word segmentation rely to a large extent on the metrical pattern of their native language, at least in stress-based languages. In Dutch and English (both languages with a preferred trochaic stress pattern), segmentation of strong-weak words develops rapidly between 7 and 10 months of age. Nevertheless, trochaic languages contain not only strong-weak words but also words with a weak-strong stress pattern. In this article, we present electrophysiological evidence of the beginnings of weak-strong word segmentation in Dutch 10-month-olds. At this age, the ability to combine different cues for efficient word segmentation does not yet seem to be completely developed. We provide evidence that Dutch infants still largely rely on strong syllables, even for the segmentation of weak-strong words.

Abstract

Two artificial-language learning experiments directly compared English, French, and Dutch listeners’ use of suprasegmental cues for continuous-speech segmentation. In both experiments, listeners heard unbroken sequences of consonant-vowel syllables, composed of recurring three- and four-syllable “words.” These words were demarcated by(a) no cue other than transitional probabilities induced by their recurrence, (b) a consistent left-edge cue, or (c) a consistent right-edge cue. Experiment 1 examined a vowel lengthening cue. All three listener groups benefited from this cue in right-edge position; none benefited from it in left-edge position. Experiment 2 examined a pitch-movement cue. English listeners used this cue in left-edge position, French listeners used it in right-edge position, and Dutch listeners used it in both positions. These findings are interpreted as evidence of both language-universal and language-specific effects. Final lengthening is a language-universal effect expressing a more general (non-linguistic) mechanism. Pitch movement expresses prominence which has characteristically different placements across languages: typically at right edges in French, but at left edges in English and Dutch. Finally, stress realization in English versus Dutch encourages greater attention to suprasegmental variation by Dutch than by English listeners, allowing Dutch listeners to benefit from an informative pitch-movement cue even in an uncharacteristic position.

Abstract

British andAmerican speakers exhibit different verb number agreement patterns when sentence subjects have collective headnouns. From linguistic andpsycholinguistic accounts of how agreement is implemented, three alternative hypotheses can be derived to explain these differences. The hypotheses involve variations in the representation of notional number, disparities in how notional andgrammatical number are used, and inequalities in the grammatical number specifications of collective nouns. We carriedout a series of corpus analyses, production experiments, andnorming studies to test these hypotheses. The results converge to suggest that British and American speakers are equally sensitive to variations in notional number andimplement subjectverb agreement in much the same way, but are likely to differ in the lexical specifications of number for collectives. The findings support a psycholinguistic theory that explains verb and pronoun agreement within a parallel architecture of lexical andsyntactic formulation.

Abstract

Rudolf Meringer (1859–1931), Indo-European philologist, published two collections of slips of the tongue, annotated and interpreted. From 1909, he was the founding editor of the cultural morphology movement's journal Wörter und Sachen. Meringer was the first to note the linguistic significance of speech errors, and his interpretations have stood the test of time. This work, rather than his mainstream philological research, has proven his most lasting linguistic contribution

Abstract

The mapping of phonetic information to lexical representations in second-language (L2) listening was examined using an eyetracking paradigm. Japanese listeners followed instructions in English to click on pictures in a display. When instructed to click on a picture of a rocket, they experienced interference when a picture of a locker was present, that is, they tended to look at the locker instead. However, when instructed to click on the locker, they were unlikely to look at the rocket. This asymmetry is consistent with a similar asymmetry previously observed in Dutch listeners’ mapping of English vowel contrasts to lexical representations. The results suggest that L2 listeners may maintain a distinction between two phonetic categories of the L2 in their lexical representations, even though their phonetic processing is incapable of delivering the perceptual discrimination required for correct mapping to the lexical distinction. At the phonetic processing level, one of the L2 categories is dominant; the present results suggest that dominance is determined by acoustic–phonetic proximity to the nearest L1 category. At the lexical processing level, representations containing this dominant category are more likely than representations containing the non-dominant category to be correctly contacted by the phonetic input.

Abstract

A perceptual learning experiment provides evidence that the mental lexicon cannot consist solely of detailed acoustic traces of recognition episodes. In a training lexical decision phase, listeners heard an ambiguous [f–s] fricative sound, replacing either [f] or [s] in words. In a test phase, listeners then made lexical decisions to visual targets following auditory primes. Critical materials were minimal pairs that could be a word with either [f] or [s] (cf. English knife–nice), none of which had been heard in training. Listeners interpreted the minimal pair words differently in the second phase according to the training received in the first phase. Therefore, lexically mediated retuning of phoneme perception not only influences categorical decisions about fricatives (Norris, McQueen, & Cutler, 2003), but also benefits recognition of words outside the training set. The observed generalization across words suggests that this retuning occurs prelexically. Therefore, lexical processing involves sublexical phonological abstraction, not only accumulation of acoustic episodes.

Abstract

The speech perception system must be flexible in responding to the variability in speech sounds caused by differences among speakers and by language change over the lifespan of the listener. Indeed, listeners use lexical knowledge to retune perception of novel speech (Norris, McQueen, & Cutler, 2003). In that study, Dutch listeners made lexical decisions to spoken stimuli, including words with an ambiguous fricative (between [f] and [s]), in either [f]- or [s]-biased lexical contexts. In a subsequent categorization test, the former group of listeners identified more sounds on an [εf] - [εs] continuum as [f] than the latter group. In the present experiment, listeners received the same exposure and test stimuli, but did not make lexical decisions to the exposure items. Instead, they counted them. Categorization results were indistinguishable from those obtained earlier. These adjustments in fricative perception therefore do not depend on explicit judgments during exposure. This learning effect thus reflects automatic retuning of the interpretation of acoustic-phonetic information.

Abstract

The goal of speech perception is understanding a speaker's message. To achieve this, listeners must recognize the words that comprise a spoken utterance. This in turn implies distinguishing these words from other minimally different words (e.g., word from bird, etc.), and this involves making phonemic distinctions. The article summarizes research on the perception of phonemic distinctions, on how listeners cope with the continuity and variability of speech signals, and on how phonemic information is mapped onto the representations of words. Particular attention is paid to theories of speech perception and word recognition.

Abstract

We propose that speech comprehension involves the activation of token representations of the phonological forms of current lexical hypotheses, separately from the ongoing construction of a conceptual interpretation of the current utterance. In a series of cross-modal priming experiments, facilitation of lexical decision responses to visual target words (e.g., time) was found for targets that were semantic associates of auditory prime words (e.g., date) when the primes were isolated words, but not when the same primes appeared in sentence contexts. Identity priming (e.g., faster lexical decisions to visual date after spoken date than after an unrelated prime) appeared, however, both with isolated primes and with primes in prosodically neutral sentences. Associative priming in sentence contexts only emerged when sentence prosody involved contrastive accents, or when sentences were terminated immediately after the prime. Associative priming is therefore not an automatic consequence of speech processing. In no experiment was there associative priming from embedded words (e.g., sedate-time), but there was inhibitory identity priming (e.g., sedate-date) from embedded primes in sentence contexts. Speech comprehension therefore appears to involve separate distinct activation both of token phonological word representations and of conceptual word representations. Furthermore, both of these types of representation are distinct from the long-term memory representations of word form and meaning.

Abstract

Participants made visual lexical decisions to upper-case words and nonwords, and then categorized an ambiguous N–H letter continuum. The lexical decision phase included different exposure conditions: Some participants saw an ambiguous letter “?”, midway between N and H, in N-biased lexical contexts (e.g., REIG?), plus words with unambiguousH(e.g., WEIGH); others saw the reverse (e.g., WEIG?, REIGN). The first group categorized more of the test continuum as N than did the second group. Control groups, who saw “?” in nonword contexts (e.g., SMIG?), plus either of the unambiguous word sets (e.g., WEIGH or REIGN), showed no such subsequent effects. Perceptual learning about ambiguous letters therefore appears to be based on lexical knowledge, just as in an analogous speech experiment (Norris, McQueen, & Cutler, 2003) which showed similar lexical influence in learning about ambiguous phonemes. We argue that lexically guided learning is an efficient general strategy available for exploitation by different specific perceptual tasks.

Abstract

We examined infants' recognition of functors and the accuracy of the representations that infants construct of the perceived word forms. Auditory stimuli were “Functor + Content Word” versus “Nonsense Functor + Content Word” sequences. Eight-, 11-, and 13-month-old infants heard both real functors and matched nonsense functors (prosodically analogous to their real counterparts but containing a segmental change). Results reveal that 13-month-olds recognized functors with attention to segmental detail. Eight-month-olds did not distinguish real versus nonsense functors. The performance of 11-month-olds fell in between that of the older and younger groups, consistent with an emerging recognition of real functors. The three age groups exhibited a clear developmental trend. We propose that in the earliest stages of vocabulary acquisition, function elements receive no segmentally detailed representations, but such representations are gradually constructed so that once vocabulary growth starts in earnest, fully specified functor representations are in place to support it.

Abstract

High-frequency functors are arguably among the earliest perceived word forms and may assist extraction of initial vocabulary items. Canadian 11- and 8-month-olds were familiarized to pseudo-nouns following either a high-frequency functor the or a low-frequency functor her versus phonetically similar mispronunciations of each, kuh and ler, and then tested for recognition of the pseudo-nouns. A preceding the (but not kuh, her, ler)facilitated extraction of the pseudo-nouns for 11-month-olds; the is thus well-specified in form for these infants. However, both the and kuh (but not her-ler )f aciliated segmentation or 8-month-olds, suggesting an initial underspecified representation of high-frequency functors.

Abstract

The distribution of energy across the noise spectrum provides the primary cues for the identification of a fricative. Formant transitions have been reported to play a role in identification of some fricatives, but the combined results so far are conflicting. We report five experiments testing the hypothesis that listeners differ in their use of formant transitions as a function of the presence of spectrally similar fricatives in their native language. Dutch, English, German, Polish, and Spanish native listeners performed phoneme monitoring experiments with pseudowords containing either coherent or misleading formant transitions for the fricatives / s / and / f /. Listeners of German and Dutch, both languages without spectrally similar fricatives, were not affected by the misleading formant transitions. Listeners of the remaining languages were misled by incorrect formant transitions. In an untimed labeling experiment both Dutch and Spanish listeners provided goodness ratings that revealed sensitivity to the acoustic manipulation. We conclude that all listeners may be sensitive to mismatching information at a low auditory level, but that they do not necessarily take full advantage of all available systematic acoustic variation when identifying phonemes. Formant transitions may be most useful for listeners of languages with spectrally similar fricatives.

Abstract

Highly proficient German users of English as a second language, and native speakers of American English, listened to nonsense sequences and responded whenever they detected an embedded English word. The responses of both groups were equivalently facilitated by preceding context that both by English and by German phonotactic constraints forced a boundary at word onset (e.g., lecture was easier to detect in moinlecture than in gorklecture, and wish in yarlwish than in plookwish. The American L1 speakers’ responses were strongly facilitated, and the German listeners’ responses almost as strongly facilitated, by contexts that forced a boundary in English but not in German thrarshlecture, glarshwish. The German listeners’ responses were significantly facilitated also by contexts that forced a boundary in German but not in English )moycelecture, loitwish, while L1 listeners were sensitive to acoustic boundary cues in these materials but not to the phonotactic sequences. The pattern of results suggests that proficient L2 listeners can acquire the phonotactic probabilities of an L2 and use them to good effect in segmenting continuous speech, but at the same time they may not be able to prevent interference from L1 constraints in their L2 listening.

Abstract

The lexicon, considered as a component of the process of recognizing speech, is a device that accepts a sound image as input and outputs meaning. Lexical access is the process of formulating an appropriate input and mapping it onto an entry in the lexicon's store of sound images matched with their meanings. This chapter addresses the problems of auditory lexical access from continuous speech. The central argument to be proposed is that utterance prosody plays a crucial role in the access process. Continuous listening faces problems that are not present in visual recognition (reading) or in noncontinuous recognition (understanding isolated words). Aspects of utterance prosody offer a solution to these particular problems.

Abstract

The recent claim by Black and Byng (1986) that lexical access in reading is subject to prosodic constraints is examined and found to be unsupported. The evidence from impaired reading which Black and Byng report is based on poorly controlled stimulus materials and is inadequately analysed and reported. An alternative explanation of their findings is proposed, and new data are reported for which this alternative explanation can account but their model cannot. Finally, their proposal is shown to be theoretically unmotivated and in conflict with evidence from normal reading.

Abstract

The present experiment tested the suggestion that human listeners may exploit durational information in speech to parse continuous utterances into words. Listeners were presented with six-syllable unpredictable utterances under noise-masking, and were required to judge between alternative word strings as to which best matched the rhythm of the masked utterances. For each utterance there were four alternative strings: (a) an exact rhythmic and word boundary match, (b) a rhythmic mismatch, and (c) two utterances with the same rhythm as the masked utterance, but different word boundary locations. Listeners were clearly able to perceive the rhythm of the masked utterances: The rhythmic mismatch was chosen significantly less often than any other alternative. Within the three rhythmically matched alternatives, the exact match was chosen significantly more often than either word boundary mismatch. Thus, listeners both perceived speech rhythm and used durational cues effectively to locate the position of word boundaries.

Abstract

SPEECH, in any language, is continuous; speakers provide few reliable cues to the boundaries of words, phrases, or other meaningful units. To understand speech, listeners must divide the continuous speech stream into portions that correspond to such units. This segmentation process is so basic to human language comprehension that psycholinguists long assumed that all speakers would do it in the same way. In previous research1,2, however, we reported that segmentation routines can be language-specific: speakers of French process spoken words syllable by syllable, but speakers of English do not. French has relatively clear syllable boundaries and syllable-based timing patterns, whereas English has relatively unclear syllable boundaries and stress-based timing; thus syllabic segmentation would work more efficiently in the comprehension of French than in the comprehension of English. Our present study suggests that at this level of language processing, there are limits to bilingualism: a bilingual speaker has one and only one basic language.

Abstract

A model of speech segmentation in a stress language is proposed, according to which the occurrence of a strong syllable triggers segmentation of the speech signal, whereas occurrence of a weak syllable does not trigger segmentation. We report experiments in which listeners detected words embedded in nonsense bisyllables more slowly when the bisyllable had two strong syllables than when it had a strong and a weak syllable; mint was detected more slowly in mintayve than in mintesh. According to our proposed model, this result is an effect of segmentation: When the second syllable is strong, it is segmented from the first syllable, and successful detection of the embedded word therefore requires assembly of speech material across a segmentation position. Speech recognition models involving phonemic or syllabic recoding, or based on strictly left-to-right processes, do not predict this result. It is argued that segmentation at strong syllables in continuous speech recognition serves the purpose of detecting the most efficient locations at which to initiate lexical access. (C) 1988 by the American Psychological Association

Abstract

Although spontaneous speech occurs more frequently in most listeners’ experience than read speech, laboratory studies of human speech recognition typically use carefully controlled materials read from a script. The phonological and prosodic characteristics of spontaneous and read speech differ considerably, however, which suggests that laboratory results may not generalize to the recognition of spontaneous and read speech materials, and their response time to detect word-initial target phonemes was measured. Response were, overall, equally fast in each speech mode. However analysis of effects previously reported in phoneme detection studies revealed significant differences between speech modes. In read speech but not in spontaneous speech, later targets were detected more rapidly than earlier targets, and targets preceded by long words were detected more rapidly than targets preceded by short words. In contrast, in spontaneous speech but not in read speech, targets were detected more rapidly in accented than unaccented words and in strong than in weak syllables. An explanation for this pattern is offered in terms of characteristic prosodic differences between spontaneous and read speech. The results support claim from previous work that listeners pay great attention to prosodic information in the process of recognizing speech.

Abstract

Previous research comparing detection times for syllables and for phonemes has consistently found that syllables are responded to faster than phonemes. This finding poses theoretical problems for strictly hierarchical models of speech recognition, in which smaller units should be able to be identified faster than larger units. However, inspection of the characteristics of previous experiments’stimuli reveals that subjects have been able to respond to syllables on the basis of only a partial analysis of the stimulus. In the present experiment, five groups of subjects listened to identical stimulus material. Phoneme and syllable monitoring under standard conditions was compared with monitoring under conditions in which near matches of target and stimulus occurred on no-response trials. In the latter case, when subjects were forced to analyze each stimulus fully, phonemes were detected faster than syllables.