Publications

Abstract

Prominence, the expression of informational weight within utterances, can be signaled by
prosodic highlighting (head-prominence, as in English) or by position (as in Korean edge-prominence).
Prominence confers processing advantages, even if conveyed only by discourse manipulations. Here
we compared processing of prominence in English and Korean, using a task that indexes processing
success, namely recognition memory. In each language, participants’ memory was tested for target
words heard in sentences in which they were prominent due to prosody, position, both or neither.
Prominence produced recall advantage, but the relative effects differed across language. For Korean
listeners the positional advantage was greater, but for English listeners prosodic and syntactic
prominence had equivalent and additive effects. In a further experiment semantic and phonological
foils tested depth of processing of the recall targets. Both foil types were correctly rejected,
suggesting that semantic processing had not reached the level at which word form was no longer
available. Together the results suggest that prominence processing is primarily driven by universal
effects of information structure; but language-specific differences in frequency of experience prompt
different relative advantages of prominence signal types. Processing efficiency increases in each case,
however, creating more accurate and more rapidly contactable memory representations.

Abstract

Science regularly experiences periods in which simply describing the world is prioritised over attempting to explain it. Cognition, this journal, came into being some 45 years ago as an attempt to lay one such period to rest; without doubt, it has helped create the current cognitive science climate in which theory is decidedly welcome. Here we summarise the reasons why a theoretical approach is imperative in our field, and call attention to some potentially counter-productive trends in which cognitive models are concerned too exclusively with how processes work at the expense of why the processes exist in the first place and thus what the goal of modelling them must be.

Abstract

Adults who as children were adopted into a different linguistic community retain knowledge of their birth language. The possession (without awareness) of such knowledge is known to facilitate the (re)learning of birth-language speech patterns; this perceptual learning predicts such adults' production success as well, indicating that the retained linguistic knowledge is abstract in nature. Adoptees' acquisition of their adopted language is fast and complete; birth-language mastery disappears rapidly, although this latter process has been little studied. Here, 46 international adoptees from China aged four to 10 years, with Dutch as their new language, plus 47 matched non-adopted Dutch-native controls and 40 matched non-adopted Chinese controls, undertook across a two-week period 10 blocks of training in perceptually identifying Chinese speech contrasts (one segmental, one tonal) which were unlike any Dutch contrasts. Chinese controls easily accomplished all these tasks. The same participants also provided speech production data in an imitation task. In perception, adoptees and Dutch controls scored equivalently poorly at the outset of training; with training, the adoptees significantly improved while the Dutch controls did not. In production, adoptees' imitations both before and after training could be better identified, and received higher goodness ratings, than those of Dutch controls. The perception results confirm that birth-language knowledge is stored and can facilitate re-learning in post-adoption childhood; the production results suggest that although processing of phonological category detail appears to depend on access to the stored knowledge, general articulatory dimensions can at this age also still be remembered, and may facilitate spoken imitation.

Abstract

Listeners learn from their past experience of listening to spoken words, and use this learning to maximise the efficiency of future word recognition. This paper summarises evidence that the facilitatory effects of drawing on past experience are mediated by abstraction, enabling learning to be generalised across new words and new listening situations. Phoneme category retuning, which allows adaptation to speaker-specific articulatory characteristics, is generalised on the basis of relatively brief experience to words previously unheard from that speaker. Abstract knowledge of prosodic regularities is applied to recognition even of novel words for which these regularities were violated. Prosodic word-boundary regularities drive segmentation of speech into words independently of the membership of the lexical candidate set resulting from the segmentation operation. Each of these different cases illustrates how abstraction from past listening experience has contributed to the efficiency of lexical recognition.

Abstract

The phoneme detection task is widely used in spoken-word recognition research. Alphabetically literate participants, however, are more used to explicit representations of letters than of phonemes. The present study explored whether phoneme detection is sensitive to how target phonemes are, or may be, orthographically realized. Listeners detected the target sounds [b, m, t, f, s, k] in word-initial position in sequences of isolated English words. Response times were faster to the targets [b, m, t], which have consistent word-initial spelling, than to the targets [f, s, k], which are inconsistently spelled, but only when spelling was rendered salient by the presence in the experiment of many irregularly spelled filler words. Within the inconsistent targets [f, s, k], there was no significant difference between responses to targets in words with more usual (foam, seed, cattle) versus less usual (phone, cede, kettle) spellings. Phoneme detection is thus not necessarily sensitive to orthographic effects; knowledge of spelling stored in the lexical representations of words does not automatically become available as word candidates are activated. However, salient orthographic manipulations in experimental input can induce such sensitivity. We attribute this to listeners' experience of the value of spelling in everyday situations that encourage phonemic decisions (such as learning new names)

Abstract

Adverse listening conditions always make the perception of speech harder, but their deleterious effect is far greater if the speech we are trying to understand is in a non-native language. An imperfect signal can be coped with by recourse to the extensive knowledge one has of a native language, and imperfect knowledge of a non-native language can still support useful communication when speech signals are high-quality. But the combination of imperfect signal and imperfect knowledge leads rapidly to communication breakdown. This phenomenon is undoubtedly well known to every reader of Speech Communication from personal experience. Many readers will also have a professional interest in explaining, or remedying, the problems it produces. The journal’s readership being a decidedly interdisciplinary one, this interest will involve quite varied scientific approaches, including (but not limited to) modelling the interaction of first and second language vocabularies and phonemic repertoires, developing targeted listening training for language learners, and redesigning the acoustics of classrooms and conference halls. In other words, the phenomenon that this special issue deals with is a well-known one, that raises important scientific and practical questions across a range of speech communication disciplines, and Speech Communication is arguably the ideal vehicle for presentation of such a breadth of approaches in a single volume. The call for papers for this issue elicited a large number of submissions from across the full range of the journal’s interdisciplinary scope, requiring the guest editors to apply very strict criteria to the final selection. Perhaps unique in the history of treatments of this topic is the combination represented by the guest editors for this issue: a phonetician whose primary research interest is in second-language speech (MLGL), an engineer whose primary research field is the acoustics of masking in speech processing (MC), and a psychologist whose primary research topic is the recognition of spoken words (AC). In the opening article of the issue, these three authors together review the existing literature on listening to second-language speech under adverse conditions, bringing together these differing perspectives for the first time in a single contribution. The introductory review is followed by 13 new experimental reports of phonetic, acoustic and psychological studies of the topic. The guest editors thank Speech Communication editor Marc Swerts and the journal’s team at Elsevier, as well as all the reviewers who devoted time and expert efforts to perfecting the contributions to this issue.

Abstract

If listening in adverse conditions is hard, then listening in a foreign language is doubly so: non-native listeners have to cope with both imperfect signals and imperfect knowledge. Comparison of native and non-native listener performance in speech-in-noise tasks helps to clarify the role of prior linguistic experience in speech perception, and, more directly, contributes to an understanding of the problems faced by language learners in everyday listening situations. This article reviews experimental studies on non-native listening in adverse conditions, organised around three principal contributory factors: the task facing listeners, the effect of adverse conditions on speech, and the differences among listener populations. Based on a comprehensive tabulation of key studies, we identify robust findings, research trends and gaps in current knowledge.

Abstract

Listeners rely on native-language rhythm in segmenting speech; in different languages, stress-, syllable- or mora-based rhythm is exploited. The rhythmic similarity hypothesis holds that where two languages have similar rhythm, listeners of each language should segment their own and the other language similarly. Such similarity in listening was previously observed only for related languages (English-Dutch; French-Spanish). We now report three experiments in which speakers of Telugu, a Dravidian language unrelated to Japanese but similar to it in crucial aspects of rhythmic structure, heard speech in Japanese and in their own language, and Japanese listeners heard Telugu. For the Telugu listeners, detection of target sequences in Japanese speech was harder when target boundaries mismatched mora boundaries, exactly the pattern that Japanese listeners earlier exhibited with Japanese and other languages. The same results appeared when Japanese listeners heard Telugu speech containing only codas permissible in Japanese. Telugu listeners' results with Telugu speech were mixed, but the overall pattern revealed correspondences between the response patterns of the two listener groups, as predicted by the rhythmic similarity hypothesis. Telugu and Japanese listeners appear to command similar procedures for speech segmentation, further bolstering the proposal that aspects of language phonological structure affect listeners' speech segmentation.

Abstract

Previous studies have shown that segmentation skills are language-specific, making it difficult to segment continuous speech in an unfamiliar language into its component words. Here we present the first study capturing the delay in segmentation and recognition in the foreign listener using ERPs. We compared the ability of Dutch adults and of English adults without knowledge of Dutch (‘foreign listeners’) to segment familiarized words from continuous Dutch speech. We used the known effect of repetition on the event-related potential (ERP) as an index of recognition of words in continuous speech. Our results show that word repetitions in isolation are recognized with equivalent facility by native and foreign listeners, but word repetitions in continuous speech are not. First, words familiarized in isolation are recognized faster by native than by foreign listeners when they are repeated in continuous speech. Second, when words that have previously been heard only in a continuous-speech context re-occur in continuous speech, the repetition is detected by native listeners, but is not detected by foreign listeners. A preceding speech context facilitates word recognition for native listeners, but delays or even inhibits word recognition for foreign listeners. We propose that the apparent difference in segmentation rate between native and foreign listeners is grounded in the difference in language-specific skills available to the listeners.

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.

Abstract

The roles which word class (open/closed) and sentential stress play in the sentence comprehension processes of both agrammatic (Broca's) aphasics and normal listeners were examined with a word monitoring task. Overall, normal listeners responded more quickly to stressed than to unstressed items, but showed no effect of word class. Aphasics also responded more quickly to stressed than to unstressed materials, but, unlike the normals, responded faster to open than to closed class words regardless of their stress. The results are interpreted as support for the theory that Broca's aphasics lack the functional underlying open/closed class word distinction used in word recognition by normal listeners.