1,020 research outputs found

    Articulatory and bottleneck features for speaker-independent ASR of dysarthric speech

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    The rapid population aging has stimulated the development of assistive devices that provide personalized medical support to the needies suffering from various etiologies. One prominent clinical application is a computer-assisted speech training system which enables personalized speech therapy to patients impaired by communicative disorders in the patient's home environment. Such a system relies on the robust automatic speech recognition (ASR) technology to be able to provide accurate articulation feedback. With the long-term aim of developing off-the-shelf ASR systems that can be incorporated in clinical context without prior speaker information, we compare the ASR performance of speaker-independent bottleneck and articulatory features on dysarthric speech used in conjunction with dedicated neural network-based acoustic models that have been shown to be robust against spectrotemporal deviations. We report ASR performance of these systems on two dysarthric speech datasets of different characteristics to quantify the achieved performance gains. Despite the remaining performance gap between the dysarthric and normal speech, significant improvements have been reported on both datasets using speaker-independent ASR architectures.Comment: to appear in Computer Speech & Language - https://doi.org/10.1016/j.csl.2019.05.002 - arXiv admin note: substantial text overlap with arXiv:1807.1094

    The role of frequency in the retrieval of nouns and verbs in aphasia

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    Background: Word retrieval in aphasia involves different levels of processing; lemma retrieval, grammatical encoding, lexeme retrieval and phonological encoding, before articulation can be programmed and executed. Several grammatical, semantic, lexical and phonological characteristics, such as word class, age of acquisition, imageability and word frequency influence the degree of success in word retrieval. It is, however, not yet clear how these factors interact. The current study focuses on retrieval of nouns and verbs in isolation and in sentence context and evaluates the impact of the mentioned factors on the performance of a group of 54 aphasic individuals. Aims: The main aim is to measure the effect of word frequency on the retrieval of nouns and verb by disentangling the influence of word class, age of acquisition, imageability and lemma and lexeme frequency on word retrieval in aphasia. Outcomes and Results: Word class, age of acquisition and imageability play a significant role in the retrieval of nouns and verbs: nouns are easier than verbs; the earlier a word has been learned and the more concrete it is, the easier it is to retrieve. When performance is controlled for these factors, lemma frequency turns out to play a minor role: only in object naming it affects word retrieval: the higher the lemma frequency of a noun, the easier it is to access. Such an effect does not exist for verbs, neither on an action-naming test, nor when verbs have to be retrieved in sentence context. Lexeme frequency was not found to be a better predictor than lemma frequency in predicting word retrieval in aphasia. Conclusions: Word retrieval in aphasia is influenced by grammatical, semantic and lexical factors. Word frequency only plays a minor role: it affects the retrieval of nouns, but not of verbs

    CroDA: Hrvatski diskursni korpus govornika s afazijom

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    The paper describes data collection and transcription to develop the Croatian discourse corpus of speakers with aphasia (CroDA), developed within the framework of the project Adult Language Processing (HRZZ 2421-UIP-11-2013) and available from 2017 as part of the AphasiaBank database of multimedia interactions for studying communication among speakers with aphasia. In accordance with the AphasiaBank Protocol, the following discourse tasks were sampled: personal narrative, picture description, story narrative and procedura discourse. Recorded speech was transcribed according to the Codes for Human Analysis of Transcripts (CHAT). CroDA, as the first discourse corpus of speakers with aphasia in Croatian, may provide new insights into specific linguistic features of discourse produced by speakers with aphasia and serve as a useful resource for quantitative and qualitative analysis.Rad opisuje postupak prikupljanja podataka i transkripciju upotrijebljenu u razvoju Hrvatskog diskursnog korpusa govornika s afazijom razvijenog u sklopu projekta Adult Language Processing (HRZZ-2421-UIP-11-2013) i dostupnog od 2017. kao dio AphasiaBank - baze multimedijalne interakcije za proučavanje komunikacije među govornicima s afazijom. U skladu s protokolom AphasiaBanka uzorkovani su diskursi na temelju četiriju zadataka: pripovijedanja osobne priče, opisa slike, prepričavanja priče i proceduralnog diskursa. Snimljeni govorni uzorci transkribirani su u skladu s Codes for Human Analysis of Transcripts (CHAT). CroDA, kao prvi diskursni korpus govornika s afazijom u hrvatskom može dati nove uvide u specifična jezična obilježja diskursne proizvodnje govornika s afazijom i poslužiti kao korisni izvor za kvantitativne i kvalitativne analize

    Comparing phoneme frequency, age of acquisition, and loss in aphasia:Implications for phonological universals

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    Phonological complexity may be central to the nature of human language. It may shape the distribution of phonemes and phoneme sequences within languages, but also determine age of acquisition and susceptibility to loss in aphasia. We evaluated this claim using frequency statistics derived from a corpus of phonologically transcribed Italian words (phonitalia, available at phonitalia,org), rankings of phoneme age of acquisition (AoA) and rate of phoneme errors in patients with apraxia of speech (AoS) as an indication of articulatory complexity. These measures were related to cross-linguistically derived markedness rankings. We found strong correspondences. AoA, however, was predicted by both apraxic errors and frequency, suggesting independent contributions of these variables. Our results support the reality of universal principles of complexity. In addition they suggest that these complexity principles have articulatory underpinnings since they modulate the production of patients with AoS, but not the production of patients with more central phonological difficulties

    Syntactic Frequency and Sentence Processing in Standard Indonesian:Data from agrammatic aphasia and ERP

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    Aphasia is a language impairment caused by focal brain damage affecting multiple channels of language. Studies have shown that one third of stroke patients show some form of aphasia. One of the key characteristics of aphasia is that in most types, patients show deficits in sentence processing. This is so much so that many aphasia assessment tools utilize sentence comprehension or production tasks to determine aphasia type or severity, or perhaps to provide a more detailed profile on the symptoms. Individuals with aphasia have been known to face difficulties in processing sentences with a derived or non-canonical structure, like the passive. While numerous studies have discussed the morphosyntactic basis of this deficit, other aspects of sentence processing such as frequency of the sentence structures are often neglected. There is considerable possibility of syntactic frequency affecting sentence processing, as a large body of research has shown the impact of word-level frequency towards language processing. Could the impairment of processing non-canonical sentences be related to the low frequency of these sentences?This thesis examines sentence processing in Standard Indonesian, a language where the passive occurs at a rate that is comparable to active sentences. Individuals with aphasia and controls were tested with sentence comprehension and production tasks, and an event-related potential study of sentence processing for healthy adults were conducted. We found the passive to be unimpaired for aphasic individuals, and we also did not find any observable processing differences between the active and the passive in the neuroimaging experiment

    PhonItalia: a phonological lexicon for Italian.

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    In this article, we present the first open-access lexical database that provides phonological representations for 120,000 Italian word forms. Each of these also includes syllable boundaries and stress markings and a comprehensive range of lexical statistics. Using data derived from this lexicon, we have also generated a set of derived databases and provided estimates of positional frequency use for Italian phonemes, syllables, syllable onsets and codas, and character and phoneme bigrams. These databases are freely available from phonitalia.org. This article describes the methods, content, and summarizing statistics for these databases. In a first application of this database, we also demonstrate how the distribution of phonological substitution errors made by Italian aphasic patients is related to phoneme frequency
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