Recognising foreign-accented speech of varying intelligibility and linguistic complexity: insights from older listeners with or without hearing loss.

OBJECTIVE: The goal of this study was to assess recognition of foreign-accented speech of varying intelligibility and linguistic complexity in older adults. It is important to understand the factors that influence the recognition of this commonly encountered type of speech, in a population that remains understudied in this regard. DESIGN: A repeated measures design was used. Listeners repeated back linguistically simple and complex sentences heard in noise. The sentences were produced by three talkers of varying intelligibility: one native American English, one foreign-accented talker of high intelligibility and one foreign-accented talker of low intelligibility. Percentage word recognition in sentences was measured. STUDY SAMPLE: Twenty-five older listeners with a range of hearing thresholds participated. RESULTS: We found a robust interaction between talker intelligibility and linguistic complexity. Recognition accuracy was higher for simple versus complex sentences, but only for the native and high intelligibility foreign-accented talkers. This pattern was present after effects of working memory capacity and hearing acuity were taken into consideration. CONCLUSION: Older listeners exhibit qualitatively different speech processing strategies for low versus high intelligibility foreign-accented talkers. Differences in recognition accuracy for words presented in simple versus in complex sentence contexts only emerged for speech over a threshold of intelligibility.

Using the Relative Entropy of Linguistic Complexity to Assess L2 Language Proficiency Development.

This study applies relative entropy in naturalistic large-scale corpus to calculate the difference among L2 (second language) learners at different levels. We chose lemma, token, POS-trigram, conjunction to represent lexicon and grammar to detect the patterns of language proficiency development among different L2 groups using relative entropy. The results show that information distribution discrimination regarding lexical and grammatical differences continues to increase from L2 learners at a lower level to those at a higher level. This result is consistent with the assumption that in the course of second language acquisition, L2 learners develop towards a more complex and diverse use of language. Meanwhile, this study uses the statistics method of time series to process the data on L2 differences yielded by traditional frequency-based methods processing the same L2 corpus to compare with the results of relative entropy. However, the results from the traditional methods rarely show regularity. As compared to the algorithms in traditional approaches, relative entropy performs much better in detecting L2 proficiency development. In this sense, we have developed an effective and practical algorithm for stably detecting and predicting the developments in L2 learners' language proficiency.

The interaction of linguistic and arithmetic factors affects adult performance on arithmetic word problems.

Performance on word problems is influenced by linguistic and arithmetic factors, and by their interaction. To study these factors and interactions, we manipulated linguistic and arithmetic factors independently in a within-participant design that included complexity parameters (a) in the domain of arithmetic: carry/borrow (no-carry/borrow vs. carry/borrow), operation (addition vs. subtraction), (b) in the domain of linguistics: nominalization (nominalized vs. verbalized form), and (c) linking the two domains: lexical consistency (linguistic predicate locally consistent vs. inconsistent with mathematical operation). Response times of 25 students solving 320 one-step word problems were measured. All four factors showed a main effect on response times, and interactions between linguistic and arithmetic factors affected response times. These interactions were observed when the linguistic and arithmetic factors were conceptually linked. Our results highlight that not only the linguistic and arithmetic complexities of an item contribute to the difficulty of a word problem, but linguistic and arithmetic factors interact. We discuss the theoretical implications for the numerical and the linguistic domain as well as the possible impact of domain-general characteristics, such as working memory limitations as a potential reason for the observed interactions between numerical and linguistic attributes.

Analyzing input quality along three dimensions: interactive, linguistic, and conceptual.

This paper provides an overview of the features of caregiver input that facilitate language learning across early childhood. We discuss three dimensions of input quality: interactive, linguistic, and conceptual. All three types of input features have been shown to predict children's language learning, though perhaps through somewhat different mechanisms. We argue that input best designed to promote language learning is interactionally supportive, linguistically adapted, and conceptually challenging for the child's age/level. Furthermore, input features interact across dimensions to promote learning. Some but not all qualities of input vary based on parent socioeconomic status, language, or culture, and contexts such as book-reading or pretend play generate uniquely facilitative input features. The review confirms that we know a great deal about the role of input quality in promoting children's development, but that there is much more to learn. Future research should examine input features across the boundaries of the dimensions distinguished here.

A transcallosal fibre system between homotopic inferior frontal regions supports complex linguistic processing.

Inferior frontal regions in the left and right hemisphere support different aspects of language processing. In the canonical model, left inferior frontal regions are mostly involved in processing based on phonological, syntactic and semantic features of language, whereas the right inferior frontal regions process paralinguistic aspects like affective prosody. Using diffusion tensor imaging (DTI)-based probabilistic fibre tracking in 20 healthy volunteers, we identify a callosal fibre system connecting left and right inferior frontal regions that are involved in linguistic processing of varying complexity. Anatomically, we show that the interhemispheric fibres are highly aligned and distributed along a rostral to caudal gradient in the body and genu of the corpus callosum to connect homotopic inferior frontal regions. In the light of converging data, taking previous DTI-based tracking studies and clinical case studies into account, our findings suggest that the right inferior frontal cortex not only processes paralinguistic aspects of language (such as affective prosody), as purported by the canonical model, but also supports the computation of linguistic aspects of varying complexity in the human brain. Our model may explain patterns of right-hemispheric contribution to stroke recovery as well as disorders of prosodic processing. Beyond language-related brain function, we discuss how inter-species differences in interhemispheric connectivity and fibre density, including the system we described here may also explain differences in transcallosal information transfer and cognitive abilities across different mammalian species.

The effect of speech training experiences on speechreading skills of Chinese children with hearing impairment.

Speechreading contributes significantly to effective communication, and persons with hearing impairment (HI) may need to rely more on speechreading. However, whether they may benefit from training/practice to improve their speechreading performance remains unclear. In this study, we examine the effect of speech training on speechreading performance of children with HI in China, and how such effect, if any, may be influenced by age. Fifty-nine HI children with speech training experiences, and fifty-eight HI children without speech training experiences completed tasks measuring their ability to speechread Chinese at the linguistic levels of words, phrases, and sentences. The children ranged from 7 to 14 years old, and were divided into four age groups by two-year age intervals. Both accuracy rate and response time data were collected. Results revealed three findings: (1) HI children with speech training experiences speechread more accurately but more slowly than those without speech training experiences; (2) while speechreading performance generally improved with age, age didn't alter the relative performance between the two groups; and (3) speechreading performance was best for phrases, and worst for sentences. These findings suggest that HI children benefit from speech training to improve their speechreading performance, and their speechreading performance is influenced by age, linguistic level, and the specific measure used.

How much does language proficiency by non-native listeners influence speech audiometric tests in noise?

OBJECTIVE: The current study investigates the extent to which the linguistic complexity of three commonly employed speech recognition tests and second language proficiency influence speech recognition thresholds (SRTs) in noise in non-native listeners. DESIGN: SRTs were measured for non-natives and natives using three German speech recognition tests: the digit triplet test (DTT), the Oldenburg sentence test (OLSA), and the Göttingen sentence test (GÖSA). STUDY SAMPLE: Sixty-four non-native and eight native listeners participated. RESULTS: Non-natives can show native-like SRTs in noise only for the linguistically easy speech material (DTT). Furthermore, the limitation of phonemic-acoustical cues in digit triplets affects speech recognition to the same extent in non-natives and natives. For more complex and less familiar speech materials, non-natives, ranging from basic to advanced proficiency in German, require on average 3-dB better signal-to-noise ratio for the OLSA and 6-dB for the GÖSA to obtain 50% speech recognition compared to native listeners. CONCLUSIONS: In clinical audiology, SRT measurements with a closed-set speech test (i.e. DTT for screening or OLSA test for clinical purposes) should be used with non-native listeners rather than open-set speech tests (such as the GÖSA or HINT), especially if a closed-set version in the patient's own native language is available.

Effects of linguistic context and noise type on speech comprehension.

Introduction: Understanding speech in background noise is an effortful endeavor. When acoustic challenges arise, linguistic context may help us fill in perceptual gaps. However, more knowledge is needed regarding how different types of background noise affect our ability to construct meaning from perceptually complex speech input. Additionally, there is limited evidence regarding whether perceptual complexity (e.g., informational masking) and linguistic complexity (e.g., occurrence of contextually incongruous words) interact during processing of speech material that is longer and more complex than a single sentence. Our first research objective was to determine whether comprehension of spoken sentence pairs is impacted by the informational masking from a speech masker. Our second objective was to identify whether there is an interaction between perceptual and linguistic complexity during speech processing. Methods: We used multiple measures including comprehension accuracy, reaction time, and processing effort (as indicated by task-evoked pupil response), making comparisons across three different levels of linguistic complexity in two different noise conditions. Context conditions varied by final word, with each sentence pair ending with an expected exemplar (EE), within-category violation (WV), or between-category violation (BV). Forty young adults with typical hearing performed a speech comprehension in noise task over three visits. Each participant heard sentence pairs presented in either multi-talker babble or spectrally shaped steady-state noise (SSN), with the same noise condition across all three visits. Results: We observed an effect of context but not noise on accuracy. Further, we observed an interaction of noise and context in peak pupil dilation data. Specifically, the context effect was modulated by noise type: context facilitated processing only in the more perceptually complex babble noise condition. Discussion: These findings suggest that when perceptual complexity arises, listeners make use of the linguistic context to facilitate comprehension of speech obscured by background noise. Our results extend existing accounts of speech processing in noise by demonstrating how perceptual and linguistic complexity affect our ability to engage in higher-level processes, such as construction of meaning from speech segments that are longer than a single sentence.

Linguistic complexity of South Slavic dialects: a new perspective on old data.

This article presents the results of a quantitative study in which the complexity levels of dialectal varieties belonging to the South Slavic dialect continuum are measured and analyzed. The sample comprises 919 data points, pertaining to the Bulgarian-Macedonian and Serbo-Croatian dialect continua. Complexity is viewed in this study as a property demonstrating variation across areas and subject to diachronic change which can be associated either with language-internal processes or with language contact. This study discusses which linguistic processes produced varying levels of complexity in the modern South Slavic varieties. In particular, a correlation of complexity with altitude and distance to the Albanian border, two factors which can be associated with degree of isolation versus contact of speech communities, is investigated for a subset of varieties spoken across the areas with bi- and multilingual population. Suggestions on which constellations of societal features could act as determinants of linguistic change are made for several areas within the South Slavic continuum. Particular attention is paid to the contact-related developments in the South Slavic varieties spoken in the areas of intensive past and present contact, such as the west of North Macedonia, the south of Montenegro, Kosovo, and Southeast Serbia.

Linguistically-Based Comparison of Different Approaches to Building Corpora for Text Simplification: A Case Study on Italian.

In this paper, we present an overview of existing parallel corpora for Automatic Text Simplification (ATS) in different languages focusing on the approach adopted for their construction. We make the main distinction between manual and (semi)-automatic approaches in order to investigate in which respect complex and simple texts vary and whether and how the observed modifications may depend on the underlying approach. To this end, we perform a two-level comparison on Italian corpora, since this is the only language, with the exception of English, for which there are large parallel resources derived through the two approaches considered. The first level of comparison accounts for the main types of sentence transformations occurring in the simplification process, the second one examines the results of a linguistic profiling analysis based on Natural Language Processing techniques and carried out on the original and the simple version of the same texts. For both levels of analysis, we chose to focus our discussion mostly on sentence transformations and linguistic characteristics that pertain to the morpho-syntactic and syntactic structure of the sentence.

Could Linguistic Complexity Be Automatically Evaluated? A Multilingual Study on WHO's Emergency Learning Platform.

The ability of assessing any type of linguistic complexity of any given contents could potentially improve knowledge reproduction, especially tacit knowledge which can be expensive during a pandemic. In this paper, we develop a simple and crosslinguistic model of complexity which considers formal accounts on the study of linguistic systems, but can be easily implemented by non-linguists' groups, e.g., communication experts and policymakers. To test our model, we conduct a study on a corpus extracted from the World Health Organization (WHO)'s emergency learning platform in 6 languages. Data extracted from open-access encyclopaedic entries act as control groups. The results show that the measurements adopted signal a trend for a minimization of complexity and can be exploited as features for (automatic) text classification.

Kolmogorov complexity metrics in assessing L2 proficiency: An information-theoretic approach.

Based on 774 argumentative writings produced by Chinese English as a foreign language (EFL) learners, this study examined the extent to which Kolmogorov complexity metrics can distinguish the proficiency levels of beginner, lower-intermediate, and upper-intermediate second language (L2) English learners. Kolmogorov complexity metric is a holistic information-theoretic approach, which measures three facets of linguistic complexity, i.e., overall, syntactic, and morphological complexity simultaneously. To assess its validity in distinguishing L2 proficiency, Kolmogorov complexity metric is compared with traditional syntactic and morphological complexity metrics as well as fine-grained syntactic complexity metrics. Results showed that Kolmogorov overall and syntactic complexity could significantly distinguish any adjacent pair of L2 levels, serving as the best separators explored in the present study. Neither Kolmogorov morphological complexity nor other complexity metrics at both the syntactic and morphological levels can distinguish between all pairs of adjacent levels. Results of correlation analysis showed that Kolmogorov syntactic complexity was not or weakly correlated with all the fine-grained syntactic complexity metrics, indicating that they may address distinct linguistic features and can complement each other to better predict different proficiency levels.

Neglected Factors Bearing on Reaction Time in Language Production.

The input to phonological reasoning are alternations, that is, variations in the pronunciation of related words, such as in electri[k] - electri[s]-ity. But phonologists cannot agree what counts as a relevant alternation: the issue is highly contentious despite a research record of over 50 years. We believe that the experimental setup presented may contribute to this debate based on a kind of evidence that was not brought to bear to date. Our experiment was thus designed to distinguish between alternations where phonological computation plays no role, and those where it has contributed to language production. The design manipulates two factors that to date have not been considered in experimental studies of language production: linguistic complexity and alternation specificity. The former is understood as extra processing demands issued by two types of linguistic activity, morphosyntactic and phonological. Our results show that reaction time latencies are longer when participants are burdened with both morphosyntactic and phonological tasks than when they carry out just a morphosyntactic task, and they are still shorter in absence of both types of demands. These results allowed us to address alternation specificity, that is, the fact that different alternations (within a language or across languages) may be driven by different production routines (an idea that is consensual among linguists but underdeveloped in the psycholinguistic literature). Our study shows that four different alternations in French produce alternation-specific signatures in reaction time latencies. These findings may thus redound to the advantage of psycholinguistic studies by identifying two new factors, as well as produce results that speak to the linguistic quarrels.

Use of Linguistic Complexity in Writing Among Chinese EFL Learners in High-Stakes Tests: Insights From a Corpus of TOEFL iBT.

In studies on second language writing, linguistic complexity exhibited by learners has long been regarded as being indicative of writing proficiency. However, there are relatively scant studies focusing on the diversity and structural elaboration of complexity in L2 production data that are extracted from high-stakes tests [such as Test of English as a Foreign Language (TOEFL) and International English Language Testing System (IELTS)]. Using a large-scale learner corpus collected from a TOEFL (internet-based test (iBT), this study aims to explore the extent to which the three dimensions of linguistic complexity, syntactic, lexical, and morphological complexity, are associated with human scoring in high-stakes tests. In addition, we also tend to tap into within-genre topic effects on the production of complexity measures by learners. To this end, a total of 1,002 writing samples were collected from a TOEFL11 corpus, and six automated-coding instruments were used to investigate the variations of complexity among Chinese English as a Foreign Language (EFL) learners. The results from the correlation analysis, multiple linear regression, and independent sample t-tests indicated that there was not a linear correlation between the majority of linguistic complexity and human-rated score levels and that proficiency among Chinese EFL learners did not signal a discriminative power in their language production. In the meantime, strong within-proficiency topic effects were found on the majority of measures in the syntactic, lexical, and morphological dimensions.

Effect of Speech Rate on Neural Tracking of Speech.

Speech comprehension requires effort in demanding listening situations. Selective attention may be required for focusing on a specific talker in a multi-talker environment, may enhance effort by requiring additional cognitive resources, and is known to enhance the neural representation of the attended talker in the listener's neural response. The aim of the study was to investigate the relation of listening effort, as quantified by subjective effort ratings and pupil dilation, and neural speech tracking during sentence recognition. Task demands were varied using sentences with varying levels of linguistic complexity and using two different speech rates in a picture-matching paradigm with 20 normal-hearing listeners. The participants' task was to match the acoustically presented sentence with a picture presented before the acoustic stimulus. Afterwards they rated their perceived effort on a categorical effort scale. During each trial, pupil dilation (as an indicator of listening effort) and electroencephalogram (as an indicator of neural speech tracking) were recorded. Neither measure was significantly affected by linguistic complexity. However, speech rate showed a strong influence on subjectively rated effort, pupil dilation, and neural tracking. The neural tracking analysis revealed a shorter latency for faster sentences, which may reflect a neural adaptation to the rate of the input. No relation was found between neural tracking and listening effort, even though both measures were clearly influenced by speech rate. This is probably due to factors that influence both measures differently. Consequently, the amount of listening effort is not clearly represented in the neural tracking.

Expressed parental concern regarding childhood stuttering and the Test of Childhood Stuttering.

PURPOSE: The purpose of the present study was to determine whether the Test of Childhood Stuttering observational rating scales (TOCS; Gillam et al., 2009) (1) differed between parents who did versus did not express concern (independent from the TOCS) about their child's speech fluency; (2) correlated with children's frequency of stuttering measured during a child-examiner conversation; and (3) correlated with the length and complexity of children's utterances, as indexed by mean length of utterance (MLU). METHOD: Participants were 183 young children ages 3:0-5:11. Ninety-one had parents who reported concern about their child's stuttering (65 boys, 26 girls) and 92 had parents who reported no such concern (50 boys, 42 girls). Participants' conversational speech during a child-examiner conversation was analyzed for (a) frequency of occurrence of stuttered and non-stuttered disfluencies, and (b) MLU. Besides expressing concern or lack thereof about their child's speech fluency, parents completed the TOCS observational rating scales documenting how often they observe different disfluency types in speech of their children, as well as disfluency-related consequences. RESULTS: There were three main findings. First, parents who expressed concern (independently from the TOCS) about their child's stuttering reported significantly higher scores on the TOCS Speech Fluency and Disfluency-Related Consequences rating scales. Second, children whose parents rated them higher on the TOCS Speech Fluency rating scale produced more stuttered disfluencies during a child-examiner conversation. Third, children with higher scores on the TOCS Disfluency-Related Consequences rating scale had shorter MLU during child-examiner conversation, across age and level of language ability. CONCLUSIONS: Findings support the use of the TOCS observational rating scales as one documentable, objective means to determine parental perception of and concern about their child's stuttering. Findings also support the notion that parents are reasonably accurate, if not reliable, judges of the quantity and quality (i.e., stuttered vs. non-stuttered) of their child's speech disfluencies. Lastly, findings that some children may decrease their verbal output in attempts to minimize instances of stuttering - as indexed by relatively low MLU and a high TOCS Disfluency-Related Consequences scores - provides strong support for sampling young children's speech and language across various situations to obtain the most representative index possible of the child's MLU and associated instances of stuttering.

Longitudinal changes in linguistic complexity among professional football players.

Reductions in spoken language complexity have been associated with the onset of various neurological disorders. The objective of this study is to analyze whether similar trends are found in professional football players who are at risk for chronic traumatic encephalopathy. We compare changes in linguistic complexity (as indexed by the type-to-token ratio and lexical density) measured from the interview transcripts of players in the National Football League (NFL) to those measured from interview transcripts of coaches and/or front-office NFL executives who have never played professional football. A multilevel mixed model analysis reveals that exposure to the high-impact sport (vs no exposure) was associated with an overall decline in language complexity scores over time. This trend persists even after controlling for age as a potential confound. The results set the stage for a prospective study to test the hypothesis that language complexity decline is a harbinger of chronic traumatic encephalopathy.

The structural linguistic complexity of lawyers' questions and children's responses in Scottish criminal courts.

In the first study to systematically assess the structural linguistic complexity of lawyers' questions of children in Scotland, we examined 56 trial transcripts of 5- to 17-year-old children testifying as alleged victims of sexual abuse. Complexity was assessed using 8 quantitative measures of each utterance's components (number of questions, phrases, clauses, sentences, false starts, average word count, word length, and sentence length) and a composite measure was used in the analyses. Lawyers did not alter the complexity of questions when prompting children of different ages. Defense lawyers asked more structurally complex questions than prosecutors. Directive questions were the least structurally complex questions, followed by option-posing questions. Suggestive questions, followed by invitations, were the most structurally complex questions. Option-posing and suggestive questions were more complex when asked by defense lawyers than prosecutors. Of suggestive questions, confrontation and tagged questions were more complex than any other question type. Increased structural complexity led to more unresponsiveness, more expressions of uncertainty, and more self-contradictions regardless of which lawyer asked, the question type, or the children's ages. These findings highlight the additional risks associated with asking some types of questions in structurally complex ways and highlight the need for further innovations (e.g., the use of intermediaries) to facilitate the questioning of vulnerable witnesses in Scottish criminal courts.

Introduction on Using the FastPCR Software and the Related Java Web Tools for PCR and Oligonucleotide Assembly and Analysis.

This chapter introduces the FastPCR software as an integrated tool environment for PCR primer and probe design, which predicts properties of oligonucleotides based on experimental studies of the PCR efficiency. The software provides comprehensive facilities for designing primers for most PCR applications and their combinations. These include the standard PCR as well as the multiplex, long-distance, inverse, real-time, group-specific, unique, overlap extension PCR for multi-fragments assembling cloning and loop-mediated isothermal amplification (LAMP). It also contains a built-in program to design oligonucleotide sets both for long sequence assembly by ligase chain reaction and for design of amplicons that tile across a region(s) of interest. The software calculates the melting temperature for the standard and degenerate oligonucleotides including locked nucleic acid (LNA) and other modifications. It also provides analyses for a set of primers with the prediction of oligonucleotide properties, dimer and G/C-quadruplex detection, linguistic complexity as well as a primer dilution and resuspension calculator. The program consists of various bioinformatical tools for analysis of sequences with the GC or AT skew, CG% and GA% content, and the purine-pyrimidine skew. It also analyzes the linguistic sequence complexity and performs generation of random DNA sequence as well as restriction endonucleases analysis. The program allows to find or create restriction enzyme recognition sites for coding sequences and supports the clustering of sequences. It performs efficient and complete detection of various repeat types with visual display. The FastPCR software allows the sequence file batch processing that is essential for automation. The program is available for download at http://primerdigital.com/fastpcr.html , and its online version is located at http://primerdigital.com/tools/pcr.html .

Are Experienced Hearing Aid Users Faster at Grasping the Meaning of a Sentence Than Inexperienced Users? An Eye-Tracking Study.

This study assessed the effects of hearing aid (HA) experience on how quickly a participant can grasp the meaning of an acoustic sentence-in-noise stimulus presented together with two similar pictures that either correctly (target) or incorrectly (competitor) depict the meaning conveyed by the sentence. Using an eye tracker, the time taken by the participant to start fixating the target (the processing time) was measured for two levels of linguistic complexity (low vs. high) and three HA conditions: clinical linear amplification (National Acoustic Laboratories-Revised), single-microphone noise reduction with National Acoustic Laboratories-Revised, and linear amplification ensuring a sensation level of ≥ 15 dB up to at least 4 kHz for the speech material used here. Timed button presses to the target stimuli after the end of the sentences (offline reaction times) were also collected. Groups of experienced (eHA) and inexperienced (iHA) HA users matched in terms of age, hearing loss, and working memory capacity took part (N = 15 each). For the offline reaction times, no effects were found. In contrast, processing times increased with linguistic complexity. Furthermore, for all HA conditions, processing times were longer (poorer) for the iHA group than for the eHA group, despite comparable speech recognition performance. Taken together, these results indicate that processing times are more sensitive to speech processing-related factors than offline reaction times. Furthermore, they support the idea that HA experience positively impacts the ability to process noisy speech quickly, irrespective of the precise gain characteristics.