Publications

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

Four experiments examined Dutch listeners’ use of suprasegmental information in spoken-word recognition. Isolated syllables excised from minimal stress pairs such as VOORnaam/voorNAAM could be reliably assigned to their source words. In lexical decision, no priming was observed from one member of minimal stress pairs to the other, suggesting that the pairs’ segmental ambiguity was removed by suprasegmental information.Words embedded in nonsense strings were harder to detect if the nonsense string itself formed the beginning of a competing word, but a suprasegmental mismatch to the competing word significantly reduced this inhibition. The same nonsense strings facilitated recognition of the longer words of which they constituted the beginning, butagain the facilitation was significantly reduced by suprasegmental mismatch. Together these results indicate that Dutch listeners effectively exploit suprasegmental cues in recognizing spoken words. Nonetheless, suprasegmental mismatch appears to be somewhat less effective in constraining activation than segmental mismatch.

Abstract

We introduce the papers in this special issue by summarising the current major issues in spoken word recognition. We argue that a full understanding of the process of lexical access during speech comprehension will depend on resolving several key representational issues: what is the form of the representations used for lexical access; how is phonological information coded in the mental lexicon; and how is the morphological and semantic information about each word stored? We then discuss a number of distinct access processes: competition between lexical hypotheses; the computation of goodness-of-fit between the signal and stored lexical knowledge; segmentation of continuous speech; whether the lexicon influences prelexical processing through feedback; and the relationship of form-based processing to the processes responsible for deriving an interpretation of a complete utterance. We conclude that further progress may well be made by swapping ideas among the different sub-domains of the discipline.

Abstract

In two word-spotting experiments, Japanese listeners detected Japanese words faster in vowel contexts (e.g., agura, to sit cross-legged, in oagura) than in consonant contexts (e.g., tagura). In the same experiments, however, listeners spotted words in vowel contexts (e.g., saru, monkey, in sarua) no faster than in moraic nasal contexts (e.g., saruN). In a third word-spotting experiment, words like uni, sea urchin, followed contexts consisting of a consonant-consonant-vowel mora (e.g., gya) plus either a moraic nasal (gyaNuni), a vowel (gyaouni) or a consonant (gyabuni). Listeners spotted words as easily in the first as in the second context (where in each case the target words were aligned with mora boundaries), but found it almost impossible to spot words in the third (where there was a single consonant, such as the [b] in gyabuni, between the beginning of the word and the nearest preceding mora boundary). Three control experiments confirmed that these effects reflected the relative ease of segmentation of the words from their contexts.We argue that the listeners showed sensitivity to the viability of sound sequences as possible Japanese words in the way that they parsed the speech into words. Since single consonants are not possible Japanese words, the listeners avoided lexical parses including single consonants and thus had difficulty recognizing words in the consonant contexts. Even though moraic nasals are also impossible words, they were not difficult segmentation contexts because, as with the vowel contexts, the mora boundaries between the contexts and the target words signaled likely word boundaries. Moraic rhythm appears to provide Japanese listeners with important segmentation cues.

Abstract

Two word-spotting experiments are reported that examine whether the Possible-Word Constraint (PWC) is a language-specific or language-universal strategy for the segmentation of continuous speech. The PWC disfavours parses which leave an impossible residue between the end of a candidate word and any likely location of a word boundary, as cued in the speech signal. The experiments examined cases where the residue was either a CVC syllable with a schwa, or a CV syllable with a lax vowel. Although neither of these syllable contexts is a possible lexical word in English, word-spotting in both contexts was easier than in a context consisting of a single consonant. Two control lexical-decision experiments showed that the word-spotting results reflected the relative segmentation difficulty of the words in different contexts. The PWC appears to be language-universal rather than language-specific.

Abstract

Four cross-modal priming experiments in Spanish addressed the role of suprasegmental and segmental information in the activation of spoken words. Listeners heard neutral sentences ending with word fragments (e.g., princi-) and made lexical decisions on letter strings presented at fragment offset. Responses were compared for fragment primes that fully matched the spoken form of the initial portion of target words, versus primes that mismatched in a single element (stress pattern; one vowel; one consonant), versus control primes. Fully matching primes always facilitated lexical decision responses, in comparison to the control condition, while mismatching primes always produced inhibition. The respective strength of the contribution of stress, vowel, and consonant (one feature mismatch or more) information did not differ statistically. The results support a model of spoken-word recognition involving automatic activation of word forms and competition between activated words, in which the activation process is sensitive to all acoustic information relevant to the language’s phonology.

Abstract

In this paper, we use articulatory measures to determine whether Dutch schwa epenthesis is an abstract phonological process or a concrete phonetic process depending on articulatory timing. We examine tongue position during /l/ before underlying schwa and epenthetic schwa and in coda position. We find greater tip raising before both types of schwa, indicating light /l/ before schwa and dark /l/ in coda position. We argue that the ability of epenthetic schwa to condition the /l/ alternation shows that Dutch schwa epenthesis is an abstract phonological process involving insertion of some unit, and cannot be accounted for within Articulatory Phonology.

Abstract

In three experiments, the processing of lexical tone in Cantonese was examined. Cantonese listeners more often accepted a nonword as a word when the only difference between the nonword and the word was in tone, especially when the F0 onset difference between correct and erroneous tone was small. Same–different judgments by these listeners were also slower and less accurate when the only difference between two syllables was in tone, and this was true whether the F0 onset difference between the two tones was large or small. Listeners with no knowledge of Cantonese produced essentially the same same-different judgment pattern as that produced by the native listeners, suggesting that the results display the effects of simple perceptual processing rather than of linguistic knowledge. It is argued that the processing of lexical tone distinctions may be slowed, relative to the processing of segmental distinctions, and that, in speeded-response tasks, tone is thus more likely to be misprocessed than is segmental structure.

Abstract

Research on the exploitation of prosodic information in the recognition of spoken language is reviewed. The research falls into three main areas: the use of prosody in the recognition of spoken words, in which most attention has been paid to the question of whether the prosodic structure of a word plays a role in initial contact with stored lexical representations; the use of prosody in the computation of syntactic structure, in which the resolution of global and local ambiguities has formed the central focus; and the role of prosody in the processing of discourse structure, in which there has been a preponderance of work on the contribution of accentuation and deaccentuation to integration of concepts with an existing discourse model. The review reveals that in each area progress has been made towards new conceptions of prosody's role in processing, and in particular this has involved abandonment of previously held deterministic views of the relationship between prosodic structure and other aspects of linguistic structure

Abstract

Psycholinguists strive to construct a model of human language processing in general. But this does not imply that they should confine their research to universal aspects of linguistic structure, and avoid research on language-specific phenomena. First, even universal characteristics of language structure can only be accurately observed cross-linguistically. This point is illustrated here by research on the role of the syllable in spoken-word recognition, on the perceptual processing of vowels versus consonants, and on the contribution of phonetic assimilation phonemena to phoneme identification. In each case, it is only by looking at the pattern of effects across languages that it is possible to understand the general principle. Second, language-specific processing can certainly shed light on the universal model of language comprehension. This second point is illustrated by studies of the exploitation of vowel harmony in the lexical segmentation of Finnish, of the recognition of Dutch words with and without vowel epenthesis, and of the contribution of different kinds of lexical prosodic structure (tone, pitch accent, stress) to the initial activation of candidate words in lexical access. In each case, aspects of the universal processing model are revealed by analysis of these language-specific effects. In short, the study of spoken-language processing by human listeners requires cross-linguistic comparison.

Abstract

We propose that word recognition in continuous speech is subject to constraints on what may constitute a viable word of the language. This Possible-Word Constraint (PWC) reduces activation of candidate words if their recognition would imply word status for adjacent input which could not be a word - for instance, a single consonant. In two word-spotting experiments, listeners found it much harder to detectapple,for example, infapple(where [f] alone would be an impossible word), than invuffapple(wherevuffcould be a word of English). We demonstrate that the PWC can readily be implemented in a competition-based model of continuous speech recognition, as a constraint on the process of competition between candidate words; where a stretch of speech between a candidate word and a (known or likely) word boundary is not a possible word, activation of the candidate word is reduced. This implementation accurately simulates both the present results and data from a range of earlier studies of speech segmentation.

Abstract

Finnish vowel harmony rules require that if the vowel in the first syllable of a word belongs to one of two vowel sets, then all subsequent vowels in that word must belong either to the same set or to a neutral set. A harmony mismatch between two syllables containing vowels from the opposing sets thus signals a likely word boundary. We report five experiments showing that Finnish listeners can exploit this information in an on-line speech segmentation task. Listeners found it easier to detect words likehymyat the end of the nonsense stringpuhymy(where there is a harmony mismatch between the first two syllables) than in the stringpyhymy(where there is no mismatch). There was no such effect, however, when the target words appeared at the beginning of the nonsense string (e.g.,hymypuvshymypy). Stronger harmony effects were found for targets containing front harmony vowels (e.g.,hymy) than for targets containing back harmony vowels (e.g.,paloinkypaloandkupalo). The same pattern of results appeared whether target position within the string was predictable or unpredictable. Harmony mismatch thus appears to provide a useful segmentation cue for the detection of word onsets in Finnish speech.

Abstract

Infants acquire whatever language is spoken in the environment into which they are born. The mental capability of the newborn child is not biased in any way towards the acquisition of one human language rather than another. Because psychologists who attempt to model the process of language comprehension are interested in the structure of the human mind, rather than in the properties of individual languages, strategies which they incorporate in their models are presumed to be universal, not language-specific. In other words, strategies of comprehension are presumed to be characteristic of the human language processing system, rather than, say, the French, English, or Igbo language processing systems. We report here, however, on a comprehension strategy which appears to be used by native speakers of French but not by native speakers of English.

Abstract

Spontaneous self-corrections in speech pose a communication problem; the speaker must make clear to the listener not only that the original Utterance was faulty, but where it was faulty and how the fault is to be corrected. Prosodic marking of corrections - making the prosody of the repair noticeably different from that of the original utterance - offers a resource which the speaker can exploit to provide the listener with such information. A corpus of more than 400 spontaneous speech repairs was analysed, and the prosodic characteristics compared with the syntactic and semantic characteristics of each repair. Prosodic marking showed no relationship at all with the syntactic characteristics of repairs. Instead, marking was associated with certain semantic factors: repairs were marked when the original utterance had been actually erroneous, rather than simply less appropriate than the repair; and repairs tended to be marked more often when the set of items encompassing the error and the repair was small rather than when it was large. These findings lend further weight to the characterization of accent as essentially semantic in function.