6,332 research outputs found
Children at risk : their phonemic awareness development in holistic instruction
Includes bibliographical references (p. 17-19
Time and information in perceptual adaptation to speech
Presubmission manuscript and supplementary files (stimuli, stimulus presentation code, data, data analysis code).Perceptual adaptation to a talker enables listeners to efficiently resolve the many-to-many mapping between variable speech acoustics and abstract linguistic representations. However, models of speech perception have not delved into the variety or the quantity of information necessary for successful adaptation, nor how adaptation unfolds over time. In three experiments using speeded classification of spoken words, we explored how the quantity (duration), quality (phonetic detail), and temporal continuity of talker-specific context contribute to facilitating perceptual adaptation to speech. In single- and mixed-talker conditions, listeners identified phonetically-confusable target words in isolation or preceded by carrier phrases of varying lengths and phonetic content, spoken by the same talker as the target word. Word identification was always slower in mixed-talker conditions than single-talker ones. However, interference from talker variability decreased as the duration of preceding speech increased but was not affected by the amount of preceding talker-specific phonetic information. Furthermore, efficiency gains from adaptation depended on temporal continuity between preceding speech and the target word. These results suggest that perceptual adaptation to speech may be understood via models of auditory streaming, where perceptual continuity of an auditory object (e.g., a talker) facilitates allocation of attentional resources, resulting in more efficient perceptual processing.NIH NIDCD (R03DC014045
A summary of the 2012 JHU CLSP Workshop on Zero Resource Speech Technologies and Models of Early Language Acquisition
We summarize the accomplishments of a multi-disciplinary workshop exploring the computational and scientific issues surrounding zero resource (unsupervised) speech technologies and related models of early language acquisition. Centered around the tasks of phonetic and lexical discovery, we consider unified evaluation metrics, present two new approaches for improving speaker independence in the absence of supervision, and evaluate the application of Bayesian word segmentation algorithms to automatic subword unit tokenizations. Finally, we present two strategies for integrating zero resource techniques into supervised settings, demonstrating the potential of unsupervised methods to improve mainstream technologies.5 page(s
Production and perception of speaker-specific phonetic detail at word boundaries
Experiments show that learning about familiar voices affects speech processing in many tasks. However, most studies focus on isolated phonemes or words and do not explore which phonetic properties are learned about or retained in memory. This work investigated inter-speaker phonetic variation involving word boundaries, and its perceptual consequences. A production experiment found significant variation in the extent to which speakers used a number of acoustic properties to distinguish junctural minimal pairs e.g. 'So he diced them'—'So he'd iced them'. A perception experiment then tested intelligibility in noise of the junctural minimal pairs before and after familiarisation with a particular voice. Subjects who heard the same voice during testing as during the familiarisation period showed significantly more improvement in identification of words and syllable constituents around word boundaries than those who heard different voices. These data support the view that perceptual learning about the particular pronunciations associated with individual speakers helps listeners to identify syllabic structure and the location of word boundaries
Why not model spoken word recognition instead of phoneme monitoring?
Norris, McQueen & Cutler present a detailed account of the decision stage of the phoneme monitoring task. However, we question whether this contributes to our understanding of the speech recognition process itself, and we fail to see why phonotactic knowledge is playing a role in phoneme recognition.
Aptitude, experience and second language pronunciation proficiency development in classroom settings: a longitudinal study
The current study longitudinally examined the influence of aptitude on second language (L2) pronunciation development when 40 first-year Japanese university students engaged in practice activities inside and outside English-as-a-Foreign-Language classrooms over one academic year. Spontaneous speech samples were elicited at the beginning, middle and end points of the project, analyzed for global, segmental, syllabic, prosodic and temporal aspects of L2 pronunciation, and linked to their aptitude and experience profiles. Results indicated that the participants generally enhanced the global comprehensibility of their speech (via reducing vowel insertion errors in complex syllables) as a function of increased classroom experience during their first semester, and explicit learning aptitude (associative memory, phonemic coding) appeared to help certain learners further enhance their pronunciation proficiency through the development of fluency and prosody. In the second semester, incidental learning ability (sound sequence recognition) was shown to be a significant predictor of the extent to which certain learners continued to improve and ultimately attain advanced-level L2 comprehensibility, largely thanks to improved segmental accuracy
Are words easier to learn from infant- than adult-directed speech? A quantitative corpus-based investigation
We investigate whether infant-directed speech (IDS) could facilitate word
form learning when compared to adult-directed speech (ADS). To study this, we
examine the distribution of word forms at two levels, acoustic and
phonological, using a large database of spontaneous speech in Japanese. At the
acoustic level we show that, as has been documented before for phonemes, the
realizations of words are more variable and less discriminable in IDS than in
ADS. At the phonological level, we find an effect in the opposite direction:
the IDS lexicon contains more distinctive words (such as onomatopoeias) than
the ADS counterpart. Combining the acoustic and phonological metrics together
in a global discriminability score reveals that the bigger separation of
lexical categories in the phonological space does not compensate for the
opposite effect observed at the acoustic level. As a result, IDS word forms are
still globally less discriminable than ADS word forms, even though the effect
is numerically small. We discuss the implication of these findings for the view
that the functional role of IDS is to improve language learnability.Comment: Draf
Listeners normalize speech for contextual speech rate even without an explicit recognition task
Speech can be produced at different rates. Listeners take this rate variation into account by normalizing vowel duration for contextual speech rate: An ambiguous Dutch word /m?t/ is perceived as short /mAt/ when embedded in a slow context, but long /ma:t/ in a fast context. Whilst some have argued that this rate normalization involves low-level automatic perceptual processing, there is also evidence that it arises at higher-level cognitive processing stages, such as decision making. Prior research on rate-dependent speech perception has only used explicit recognition tasks to investigate the phenomenon, involving both perceptual processing and decision making. This study tested whether speech rate normalization can be observed without explicit decision making, using a cross-modal repetition priming paradigm. Results show that a fast precursor sentence makes an embedded ambiguous prime (/m?t/) sound (implicitly) more /a:/-like, facilitating lexical access to the long target word "maat" in a (explicit) lexical decision task. This result suggests that rate normalization is automatic, taking place even in the absence of an explicit recognition task. Thus, rate normalization is placed within the realm of everyday spoken conversation, where explicit categorization of ambiguous sounds is rare
Exploiting Low-dimensional Structures to Enhance DNN Based Acoustic Modeling in Speech Recognition
We propose to model the acoustic space of deep neural network (DNN)
class-conditional posterior probabilities as a union of low-dimensional
subspaces. To that end, the training posteriors are used for dictionary
learning and sparse coding. Sparse representation of the test posteriors using
this dictionary enables projection to the space of training data. Relying on
the fact that the intrinsic dimensions of the posterior subspaces are indeed
very small and the matrix of all posteriors belonging to a class has a very low
rank, we demonstrate how low-dimensional structures enable further enhancement
of the posteriors and rectify the spurious errors due to mismatch conditions.
The enhanced acoustic modeling method leads to improvements in continuous
speech recognition task using hybrid DNN-HMM (hidden Markov model) framework in
both clean and noisy conditions, where upto 15.4% relative reduction in word
error rate (WER) is achieved
Strategies for Representing Tone in African Writing Systems
Tone languages provide some interesting challenges for the designers of new orthographies.
One approach is to omit tone marks, just as stress is not marked in English (zero marking).
Another approach is to do phonemic tone analysis and then make heavy use of diacritic
symbols to distinguish the `tonemes' (exhaustive marking). While orthographies based on
either system have been successful, this may be thanks to our ability to manage inadequate
orthographies rather than to any intrinsic advantage which is afforded by one or the other
approach. In many cases, practical experience with both kinds of orthography in sub-Saharan
Africa has shown that people have not been able to attain the level of reading and writing
fluency that we know to be possible for the orthographies of non-tonal languages. In some
cases this can be attributed to a sociolinguistic setting which does not favour vernacular
literacy. In other cases, the orthography itself might be to blame. If the orthography of a tone
language is difficult to user or to learn, then a good part of the reason, I believe, is that the
designer either has not paid enough attention to the function of tone in the language, or has
not ensured that the information encoded in the orthography is accessible to the ordinary
(non-linguist) user of the language. If the writing of tone is not going to continue to be a
stumbling block to literacy efforts, then a fresh approach to tone orthography is required, one
which assigns high priority to these two factors.
This article describes the problems with orthographies that use too few or too many tone
marks, and critically evaluates a wide range of creative intermediate solutions. I review the
contributions made by phonology and reading theory, and provide some broad methodological
principles to guide someone who is seeking to represent tone in a writing system. The tone
orthographies of several languages from sub-Saharan Africa are presented throughout the
article, with particular emphasis on some tone languages of Cameroon
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