The role of phonemes and syllables in the perceived similarity of speech sounds for children

In two experiments, we investigated the factors that influence the perceived similarity of speech sounds at two developmental levels. Kindergartners and second graders were asked to classify nonsense words, which were related by syllable and phoneme correspondences. The results support the existence of a developmental trend toward increased attention to individual phonemic segments. Moreover, one significant factor in determining the perceived similarity of speech sounds appears to be the position of the component correspondences; attention to the beginning of utterances may have developmental priority. An unexpected finding was that the linguistic status of the unit involved in a correspondence (whether it was a syllable or a phoneme) did not seem particularly important. Apparently, the factors which contribute to the perceived similarity of speech sounds in the classification task are not identical to those which underlie performance in explicit segmentation and manipulation tasks, since in the latter sort of task, syllables are more accessible than phonemes for young children. The present task may tap a level of processing that is closer to the one entailed in word recognition and lexical access.     

汉语口语词汇产生的音韵编码单元：内隐启动范式的ERP研究

本研究中选择英语水平低的汉语母语者, 排除作为二语的英语音韵编码单元(音素)可能对汉语口语词汇产生过程的影响后, 运用事件相关电位技术, 考察了汉语口语产生过程中音节和音素效应的时间进程。实验采用内隐启动范式, 要求被试看到提示词之后说出对应的目标词。事件相关电位分析结果发现, 音节效应出现在线索词呈现后的100~400 ms之间, 音素效应出现在500~600 ms之间, 波形表现为相关条件比无关条件的波形更正。这表明在词汇选择之后的音韵编码阶段讲话者首先提取的单元是音节, 而音素效应出现的时间窗口可能是音韵编码阶段后期或者是语音编码阶段, 结果验证了合适编码单元假说的观点。     

Syllables as units in speech production: Data from aphasia

The syllable has received considerable empirical support as a unit of processing in speech perception, but its status in speech production remains unclear. Some researchers propose that syllables are individually represented and retrieved during phonological encoding (e.g., Dell, 1986; Ferrand, Segui, & Grainger, 1996; MacKay, 1987). We test this hypothesis by examining the influence of syllable frequency on the phonological errors of two aphasics. These individuals both had an impairment in phonological encoding, but appeared to differ in the precise locus of that impairment. They each read aloud and repeated 110 pairs of words matched for syllabic complexity, but differing in final syllable frequency. Lexical frequency was also controlled. Neither aphasic was more error-prone on low than on high frequency syllables (indeed, one showed a near-significant reverse effect), and neither showed a preference for more frequent syllables in their errors. These findings provide no support for the view that syllables are individually represented and accessed during phonological encoding.     

Using mnemonic images and explicit sound contrasting to help Japanese children learn English alphabet sounds

Although mnemonics have been shown to be effective in remembering letter-sound associations, the use of foreign words as cues for English phonemes had not been investigated. Learning phonemes in Japan is challenging because the Japanese language is based on a different sound unit called mora (mostly consonant-vowel combinations). This study investigated the effectiveness of using mnemonic images utilizing Japanese words as cues for the phonemes, and explicit sound contrasting of phonemic sounds with morae they could be confused with, in facilitating children's acquisition of knowledge about alphabet letter-sound correspondence. The participants were 140 6th-grade Japanese students who were taught phoneme-consonant correspondence, with or without the use of mnemonics or explicit sound contrasting. Analysis of the students’ pre- and post-instruction assessments revealed significant interaction effects between types of instruction provided and instruction phase, indicating better performance in letter-sound association as a consequence of the inclusion of both mnemonics and explicit sound contrasting.     

Disorder in sequential speech perception: a case study on pure word deafness

We described disorders of a patient which were uniquely restricted to speech perception of syllable sequences after brain damage. The results of series of experiments using syllable sequences showed "negative recency effect," in which the subject's repetition performance at the latter syllable position was remarkably poor. Experimental analyses suggested that the "negative recency effect" could be due to dual factors: the lower rate of processing of speech sounds and the memory load of holding processes of preceding syllables imposed on the succeeding phonological processing. The results also suggested that the holding processes which imposed the memory load on the succeeding auditory phonological coding processing were modality nonspecific.     

A Cross-Linguistic Speech Error Investigation of Functional Complexity

This work is a systematic, cross-linguistic examination of speech errors in English, Hindi, Japanese, Spanish and Turkish. It first describes a methodology for the generation of parallel corpora of error data, then uses these data to examine three general hypotheses about the relationship between language structure and the speech production system. All of the following hypotheses were supported by the data. Languages are equally complex. No overall differences were found in the numbers of errors made by speakers of the five languages in the study. Languages are processed in similar ways. English-based generalizations about language production were tested to see to what extent they would hold true across languages. It was found that, to a large degree, languages follow similar patterns. However, the relative numbers of phonological anticipations and perseverations in other languages did not follow the English pattern. Languages differ in that speech errors tend to cluster around loci of complexity within each language. Languages such as Turkish and Spanish, which have more inflectional morphology, exhibit more errors involving inflected forms, while languages such as Japanese, with rich systems of closed-class forms, tend to have more errors involving closed-class items.     

音节在语言产生中的作用

综述了音节在语言产生中的作用。首先简单介绍了音节的概念;然后介绍了两类语言产生理论关于音节存储和音节如何起作用的不同观点;第三,从实验研究的主要范式和主要问题两个方面分析了目前在语言产生领域对音节的研究成果及存在的问题。主要的研究范式有：掩蔽启动范式、重复启动范式、内隐启动范式和图画－词汇干扰实验范式。研究的主要问题有：音节是否是言语产生中的功能单位,音节在言语产生中是如何起作用的,以及音节启动效应的发生位置。最后根据汉语音节的特点,分析了汉语词汇产生中对音节的研究以及今后的研究趋势     

The functional unit in phonological encoding: evidence for moraic representation in native Japanese speakers

Speech production studies have shown that the phonological form of a word is made up of phonemic segments in stress-timed languages (e.g., Dutch) and of syllables in syllable-timed languages (e.g., Chinese). To clarify the functional unit of mora-timed languages, the authors asked native Japanese speakers to perform an implicit priming task (A. S. Meyer, 1990, 1991). In Experiment 1, participants could speed up their production latencies when initial consonant and vowel (CV) of a target word were known in advance but failed to do so when the vowel was unknown. In Experiment 2, prior knowledge of the consonant and glide (Cj) produced no significant priming effect. However, in Experiment 3, significant effects were found for the consonant-vowel coupled with a nasal coda (CVN) and the consonant with a diphthong (CVV), compared with the consonant-vowel alone (CV). These results suggest that the implicit priming effects for Japanese are closely related to the CV-C and CV-V structure, called the mora. The authors discuss cross-linguistic differences in the phonological representation involved in phonological encoding, within current theories of word production.     

Syllable frequency and syllable structure in apraxia of speech

Recent accounts of the pathomechanism underlying apraxia of speech (AOS) were based on the speech production model of Levelt, Roelofs, and Meyer, and Meyer (1999)1999. The apraxic impairment was localized to the phonetic encoding level where the model postulates a mental store of motor programs for high-frequency syllables. Varley and Whiteside (2001a) assumed that in patients with AOS syllabic motor programs are no longer accessible and that these patients are required to use a subsyllabic encoding route. In this study, we tested this hypothesis by exploring the influence of syllable frequency and syllable structure on word repetition in 10 patients with AOS. A significant effect of syllable frequency on error rates was found. Moreover, apraxic errors on consonant clusters were influenced by their position relative to syllable boundaries. These results demonstrate that apraxic patients have access to the syllabary, but that they fail to retrieve the syllabic motor patterns correctly. Our findings are incompatible with a subsyllabic route model of apraxia of speech.     

Some consequences of stimulus variability on speech processing by 2-month-old infants.

The present study explores how stimulus variability in speech production influences the 2-month-old infant's perception and memory for speech sounds. Experiment 1 focuses on the consequences of talker variability for the infant's ability to detect differences between speech sounds. When tested with high-amplitude sucking (HAS) procedure, infants who listened to versions of a syllable, such as [symbol: see text], produced by 6 male and 6 female talkers, detected a change to another syllable, such as [symbol: see text], uttered by the same group of talkers. In fact, infants exposed to multiple talkers performed as well as other infants who heard utterances produced by only a single talker. Moreover, other results showed that infants discriminate the voices of the individual talkers, although discriminating one mixed group of talkers (3 males and 3 females) from another is too difficult for them. Experiment 2 explored the consequences of talker variability on infants' memory for speech sounds. The HAS procedure was modified by introducing a 2-min delay period between the familiarization and test phases of the experiment. Talker variability impeded infants' encoding of speech sounds. Infants who heard versions of the same syllable produced by 12 different talkers did not detect a change to a new syllable produced by the same talkers after the delay period. However, infants who heard the same syllable produced by a single talker were able to detect the phonetic change after the delay. Finally, although infants who heard productions from a single talker retained information about the phonetic structure of the syllable during the delay, they apparently did not retain information about the identity of the talker. Experiment 3 reduced the range of variability across talkers and investigated whether variability interferes with retention of all speech information. Although reducing the range of variability did not lead to retention of phonetic details, infants did recognize a change in the gender of the talkers' voices (from male to female or vice versa) after a 2-min delay. Two additional experiments explored the consequences of limiting the variability to a single talker. In Experiment 4, with an immediate testing procedure, infants exposed to 12 different tokens of one syllable produced by the same talker discriminated these from 12 tokens of another syllable.(ABSTRACT TRUNCATED AT 400 WORDS)     

Irrelevant sound disrupts speech production: Exploring the relationship between short-term memory and experimentally induced slips of the tongue

To explore the relationship between short-term memory and speech production, we developed a speech error induction technique. The technique, which was adapted from a Japanese word game, exposed participants to an auditory distractor word immediately before the utterance of a target word. In Experiment 1, the distractor words that were phonologically similar to the target word led to a greater number of errors in speaking the target than did the dissimilar distractor words. Furthermore, the speech error scores were significantly correlated with memory span scores. In Experiment 2, memory span scores were again correlated with the rate of the speech errors that were induced from the task-irrelevant speech sounds. Experiment 3 showed a strong irrelevant-sound effect in the serial recall of nonwords. The magnitude of the irrelevant-sound effects was not affected by phonological similarity between the to-be-remembered nonwords and the irrelevant-sound materials. Analysis of recall errors in Experiment 3 also suggested that there were no essential differences in recall error patterns between the dissimilar and similar irrelevant-sound conditions. Weproposed two different underlying mechanisms in immediate memory, one operating via the phonological short-term memory store and the other via the processes underpinning speech production.     

Alterations of the phonetic coding of speech sounds during repetition

One aspect of the comprehension of speech is the assignment of a phonetic representation to the sounds being heard. However, if a person listens to a meaningless syllable that is continually repeated, over time he will hear the syllable undergo a variety of changes. These changes are very systematic in character and represent alterations in the phonetic coding assigned to an unchanging sound stimulus. When the restricted nature of the changes that occur is analyzed phonetically, these changes are found to invlove a reorganization of the phones constituting the syllables and changes in a small number of distinctive features.     

Effects of syllable structure in aphasic errors: implications for a new model of speech production

Current models of word production assume that words are stored as linear sequences of phonemes which are structured into syllables only at the moment of production. This is because syllable structure is always recoverable from the sequence of phonemes. In contrast, we present theoretical and empirical evidence that syllable structure is lexically represented. Storing syllable structure would have the advantage of making representations more stable and resistant to damage. On the other hand, re-syllabifications affect only a minimal part of phonological representations and occur only in some languages and depending on speech register. Evidence for these claims comes from analyses of aphasic errors which not only respect phonotactic constraints, but also avoid transformations which move the syllabic structure of the word further away from the original structure, even when equating for segmental complexity. This is true across tasks, types of errors, and, crucially, types of patients. The same syllabic effects are shown by apraxic patients and by phonological patients who have more central difficulties in retrieving phonological representations. If syllable structure was only computed after phoneme retrieval, it would have no way to influence the errors of phonological patients. Our results have implications for psycholinguistic and computational models of language as well as for clinical and educational practices.     

Syllables in the processing of spoken Italian

Five experiments explored the role of the syllable in the processing of spoken Italian. According to the syllabic hypothesis, the sublexical unit used by speakers of Romance languages to segment speech and access the lexicon is the syllable. However, languages with different degrees of acoustic-phonetic transparency give rise to syllabic effects that vary in robustness. It follows from this account that speakers of phonologically similar languages should behave in a similar way. By exploiting the similarities between Spanish and Italian, the authors tested this prediction in Experiments 1-4. Indeed, Italian listeners were found to produce syllabic effects similar to those observed in Spanish listeners. In Experiment 5, the predictions of the syllabic hypothesis with respect to lexical access were tested. The results corroborated these predictions. The findings are discussed in relation to current models of speech processing.     

Towards an auditory account of speech rhythm: application of a model of the auditory 'primal sketch' to two multi-language corpora

The world's languages display important differences in their rhythmic organization; most particularly, different languages seem to privilege different phonological units (mora, syllable, or stress foot) as their basic rhythmic unit. There is now considerable evidence that such differences have important consequences for crucial aspects of language acquisition and processing. Several questions remain, however, as to what exactly characterizes the rhythmic differences, how they are manifested at an auditory/acoustic level and how listeners, whether adult native speakers or young infants, process rhythmic information. In this paper it is proposed that the crucial determinant of rhythmic organization is the variability in the auditory prominence of phonetic events. In order to test this auditory prominence hypothesis, an auditory model is run on two multi-language data-sets, the first consisting of matched pairs of English and French sentences, and the second consisting of French, Italian, English and Dutch sentences. The model is based on a theory of the auditory primal sketch, and generates a primitive representation of an acoustic signal (the rhythmogram) which yields a crude segmentation of the speech signal and assigns prominence values to the obtained sequence of events. Its performance is compared with that of several recently proposed phonetic measures of vocalic and consonantal variability.     

Motor movement matters: The flexible abstractness of inner speech

Inner speech is typically characterized as either the activation of abstract linguistic representations or a detailed articulatory simulation that lacks only the production of sound. We present a study of the speech errors that occur during the inner recitation of tongue-twister-like phrases. Two forms of inner speech were tested: inner speech without articulatory movements and articulated (mouthed) inner speech. Although mouthing one’s inner speech could reasonably be assumed to require more articulatory planning, prominent theories assume that such planning should not affect the experience of inner speech and, consequently, the errors that are “heard” during its production. The errors occurring in articulated inner speech exhibited the phonemic similarity effect and the lexical bias effect—two speech-error phenomena that, in overt speech, have been localized to an articulatory-feature-processing level and a lexical—phonological level, respectively. In contrast, errors in unarticulated inner speech did not exhibit the phonemic similarity effect—just the lexical bias effect. The results are interpreted as support for a flexible abstraction account of inner speech. This conclusion has ramifications for the embodiment of language and speech and for the theories of speech production.     

Evidence for a specific cross-modal association deficit in dyslexia: an electrophysiological study of letter-speech sound processing

The phonological deficit theory of dyslexia assumes that degraded speech sound representations might hamper the acquisition of stable letter-speech sound associations necessary for learning to read. However, there is only scarce and mainly indirect evidence for this assumed letter-speech sound association problem. The present study aimed at clarifying the nature and the role of letter-speech sound association problems in dyslexia by analysing event-related potentials (ERP) of 11-year-old dyslexic children to speech sounds in isolation or combined with letters, which were presented either simultaneously with or 200 ms before the speech sounds. Recent studies with normal readers revealed that letters systematically modulated speech sound processing in an early (mismatch negativity or MMN) and late (Late Discriminatory Negativity or LDN) time-window. The amplitude of the MMN and LDN to speech sounds was enhanced when speech sounds were presented with letters. The dyslexic readers in the present study, however, did not exhibit any early influences of letters on speech sounds even after 4 years of reading instruction, indicating no automatic integration of letters and speech sounds. Interestingly, they revealed a systematic late effect of letters on speech sound processing, probably reflecting the mere association of letters and speech sounds. This pattern is strongly divergent from that observed in age-matched normal readers, who showed both early and late effects, but reminiscent of that observed in beginner normal readers in a previous study (Froyen, Bonte, van Atteveldt & Blomert, 2009). The finding that the quality of letter-speech sound processing is directly related to reading fluency urges further research into the role of audiovisual integration in the development of reading failure in dyslexia.