Recognition of Spanish consonants in 8-talker babble by children with cochlear implants, and by children and adults with normal hearing.

This paper presents the results of closed-set recognition task for 80 Spanish consonant-vowel sounds in 8-talker babble. Three groups of subjects participated in the study: a group of children using cochlear implants (CIs; age range: 7-13), an age-matched group of children with normal hearing (NH), and a group of adults with NH. The speech-to-noise ratios at which the participants recognized 33% of the target consonants were +7.8 dB, -3 dB, and -6 dB, respectively. In order to clarify the qualitative differences between the groups, groups were matched for the percentage of recognized syllables. As compared with the two groups with NH, the children with CIs: (1) produced few "I do not know" responses; (2) frequently selected the voiced stops (i.e., /b, d, ɡ/) and the most energetic consonants (i.e., /l, r, ʝ, s, ʧ/); (3) showed no vowel context effects; and (4) had a robust voicing bias. As compared with the adults with NH, both groups of children showed a fronting bias in place of articulation errors. The factors underlying these error patterns are discussed.

Analysis of Spanish consonant recognition in 8-talker babble.

This paper presents the results of a closed-set recognition task for 80 Spanish consonant-vowel sounds (16 C × 5 V, spoken by 2 talkers) in 8-talker babble (-6, -2, +2 dB). A ranking of resistance to noise was obtained using the signal detection d' measure, and confusion patterns were analyzed using a graphical method (confusion graphs). The resulting ranking indicated the existence of three resistance groups: (1) high resistance: /ʧ, s, ʝ/; (2) mid resistance: /r, l, m, n/; and (3) low resistance: /t, θ, x, É¡, b, d, k, f, p/. Confusions involved mostly place of articulation and voicing errors, and occurred especially among consonants in the same resistance group. Three perceptual confusion groups were identified: the three low-energy fricatives (i.e., /f, θ, x/), the six stops (i.e., /p, t, k, b, d, É¡/), and three consonants with clear formant structure (i.e., /m, n, l/). The factors underlying consonant resistance and confusion patterns are discussed. The results are compared with data from other languages.

Sensitive periods and language in cochlear implant users.

This study explores the hypothesis that the existence of a short sensitive period for lower-level speech perception/articulation skills, and a long one for higher-level language skills, may partly explain the language outcomes of children with cochlear implants (CIs). The participants were fourteen children fitted with a CI before their second birthday. Data about their language skills and the environmental conditions (e.g. Family Involvement in rehabilitation) were obtained over a period of three years. Age at implantation correlated exclusively with the ratio of errors of place of articulation, a phonological feature for which CIs provide insufficient information. The degree of Family Involvement was significantly correlated with the remaining language measures. We conclude that small plasticity reductions affecting lower-level skills may partly explain the difficulties of some CI users in developing language.

The emergence of productive speech and language in Spanish-learning paediatric cochlear implant users.

It has been proposed that cochlear implant users may develop robust categorical perception skills, but that they show limited precision in perception. This article explores if a parallel contrast is observable in production, and if, despite acquiring typical linguistic representations, their early words are inconsistent. The participants were eight Spanish-learning deaf children implanted before their second birthday. Two studies examined the transition from babbling to words, and the one-word period. Study 1 found that the participants used the same sound types in babbling and in words, indicating that production is guided by stored motor patterns. No clear evidence of inconsistent production was observed. Study 2 found that in the one-word period CI users develop typical prosodic representations, but that their productions are highly unstable. Results are discussed in terms of the role of auditory feedback for the development of productive language skills.

Lexical and grammatical development in a child with cochlear implant and attention deficit: A case study.

This is the first study to explore lexical and grammatical development in a deaf child diagnosed with Attention Deficit Hyperactivity Disorder, Inattentive sub-type (ADHD/I). The child, whose family language was Spanish, was fitted with a cochlear implant (CI) when she was 18 months old. ADHD/I, for which she was prescribed medication, was diagnosed 3;6 years later. Speech samples were videotaped over the first 4 years of CI use and during a follow-up session 1 year later. Samples were transcribed according to CHAT conventions and several measures of expressive language were obtained. Receptive language was evaluated with standardized tests. Results show that while some aspects of her development seemed relatively positive (e.g., acquisition of verbal morphemes at the same auditory age as typical children), other characteristics were atypical for a CI user: (1) preference for paralexical expressions in early lexicon; (2) lexical errors in colours and other abstract words; and (3) low MLU and varied grammatical errors including disorganized discourse. Medication had a positive effect on all these characteristics, providing evidence of a link with ADHD/I. This study concludes that ADHD/I had a direct impact on the lexical and grammatical development in this child, as well as an indirect influence over her communicative style. More studies are needed to explore language characteristics of children with CI and ADHD.

Consonant and vowel articulation accuracy in younger and middle-aged Spanish healthy adults.

Children acquire vowels earlier than consonants, and the former are less vulnerable to speech disorders than the latter. This study explores the hypothesis that a similar contrast exists later in life and that consonants are more vulnerable to ageing than vowels. Data was obtained with two experiments comparing the speech of Younger Adults (YAs) and Middle-aged Adults (MAs). In the first experiment an Automatic Speech Recognition (ASR) system was trained with a balanced corpus of 29 YAs and 27 MAs. The productions of each speaker were obtained in a Spanish language word (W) and non-word (NW) repetition task. The performance of the system was evaluated with the same corpus used for training using a cross validation approach. The ASR system recognized to a similar extent the Ws of both groups of speakers, but it was more successful with the NWs of the YAs than with those of the MAs. Detailed error analysis revealed that the MA speakers scored below the YA speakers for consonants and also for the place and manner of articulation features; the results were almost identical in both groups of speakers for vowels and for the voicing feature. In the second experiment a group of healthy native listeners was asked to recognize isolated syllables presented with background noise. The target speakers were one YA and one MA that had taken part in the first experiment. The results were consistent with those of the ASR experiment: the manner and place of articulation were better recognized, and vowels and voicing were worse recognized, in the YA speaker than in the MA speaker. We conclude that consonant articulation is more vulnerable to ageing than vowel articulation. Future studies should explore whether or not these early and selective changes in articulation accuracy might be caused by changes in speech perception skills (e.g., in auditory temporal processing).

Developmental Dynamic Dysphasia: Are Bilateral Brain Abnormalities a Signature of Inefficient Neural Plasticity?

The acquisition and evolution of speech production, discourse and communication can be negatively impacted by brain malformations. We describe, for the first time, a case of developmental dynamic dysphasia (DDD) in a right-handed adolescent boy (subject D) with cortical malformations involving language-eloquent regions (inferior frontal gyrus) in both the left and the right hemispheres. Language evaluation revealed a markedly reduced verbal output affecting phonemic and semantic fluency, phrase and sentence generation and verbal communication in everyday life. Auditory comprehension, repetition, naming, reading and spelling were relatively preserved, but executive function was impaired. Multimodal neuroimaging showed a malformed cerebral cortex with atypical configuration and placement of white matter tracts bilaterally and abnormal callosal fibers. Dichotic listening showed right hemisphere dominance for language, and functional magnetic resonance imaging (fMRI) additionally revealed dissociated hemispheric language representation with right frontal activation for phonology and bilateral dominance for semantic processing. Moreover, subject D also had congenital mirror movements (CMM), defined as involuntary movements of one side of the body that mirror intentional movements of the other side. Transcranial magnetic stimulation and fMRI during voluntary unimanual (left and right) hand movements showed bilateral motor cortex recruitment and tractography revealed a lack of decussation of bilateral corticospinal tracts. Genetic testing aimed to detect mutations that disrupt the development of commissural tracts correlating with CMM (e.g., Germline DCC mutations) was negative. Overall, our findings suggest that DDD in subject D resulted from the underdevelopment of the left inferior frontal gyrus with limited capacity for plastic reorganization by its homologous counterpart in the right hemisphere. Corpus callosum anomalies probably contributed to hinder interhemispheric connectivity necessary to compensate language and communication deficits after left frontal involvement.

Cholinergic Potentiation and Audiovisual Repetition-Imitation Therapy Improve Speech Production and Communication Deficits in a Person with Crossed Aphasia by Inducing Structural Plasticity in White Matter Tracts.

Donepezil (DP), a cognitive-enhancing drug targeting the cholinergic system, combined with massed sentence repetition training augmented and speeded up recovery of speech production deficits in patients with chronic conduction aphasia and extensive left hemisphere infarctions (Berthier et al., 2014). Nevertheless, a still unsettled question is whether such improvements correlate with restorative structural changes in gray matter and white matter pathways mediating speech production. In the present study, we used pharmacological magnetic resonance imaging to study treatment-induced brain changes in gray matter and white matter tracts in a right-handed male with chronic conduction aphasia and a right subcortical lesion (crossed aphasia). A single-patient, open-label multiple-baseline design incorporating two different treatments and two post-treatment evaluations was used. The patient received an initial dose of DP (5 mg/day) which was maintained during 4 weeks and then titrated up to 10 mg/day and administered alone (without aphasia therapy) during 8 weeks (Endpoint 1). Thereafter, the drug was combined with an audiovisual repetition-imitation therapy (Look-Listen-Repeat, LLR) during 3 months (Endpoint 2). Language evaluations, diffusion weighted imaging (DWI), and voxel-based morphometry (VBM) were performed at baseline and at both endpoints in JAM and once in 21 healthy control males. Treatment with DP alone and combined with LLR therapy induced marked improvement in aphasia and communication deficits as well as in selected measures of connected speech production, and phrase repetition. The obtained gains in speech production remained well-above baseline scores even 4 months after ending combined therapy. Longitudinal DWI showed structural plasticity in the right frontal aslant tract and direct segment of the arcuate fasciculus with both interventions. VBM revealed no structural changes in other white matter tracts nor in cortical areas linked by these tracts. In conclusion, cholinergic potentiation alone and combined with a model-based aphasia therapy improved language deficits by promoting structural plastic changes in right white matter tracts.

Mild Developmental Foreign Accent Syndrome and Psychiatric Comorbidity: Altered White Matter Integrity in Speech and Emotion Regulation Networks.

Foreign accent syndrome (FAS) is a speech disorder that is defined by the emergence of a peculiar manner of articulation and intonation which is perceived as foreign. In most cases of acquired FAS (AFAS) the new accent is secondary to small focal lesions involving components of the bilaterally distributed neural network for speech production. In the past few years FAS has also been described in different psychiatric conditions (conversion disorder, bipolar disorder, and schizophrenia) as well as in developmental disorders (specific language impairment, apraxia of speech). In the present study, two adult males, one with atypical phonetic production and the other one with cluttering, reported having developmental FAS (DFAS) since their adolescence. Perceptual analysis by naïve judges could not confirm the presence of foreign accent, possibly due to the mildness of the speech disorder. However, detailed linguistic analysis provided evidence of prosodic and segmental errors previously reported in AFAS cases. Cognitive testing showed reduced communication in activities of daily living and mild deficits related to psychiatric disorders. Psychiatric evaluation revealed long-lasting internalizing disorders (neuroticism, anxiety, obsessive-compulsive disorder, social phobia, depression, alexithymia, hopelessness, and apathy) in both subjects. Diffusion tensor imaging (DTI) data from each subject with DFAS were compared with data from a group of 21 age- and gender-matched healthy control subjects. Diffusion parameters (MD, AD, and RD) in predefined regions of interest showed changes of white matter microstructure in regions previously related with AFAS and psychiatric disorders. In conclusion, the present findings militate against the possibility that these two subjects have FAS of psychogenic origin. Rather, our findings provide evidence that mild DFAS occurring in the context of subtle, yet persistent, developmental speech disorders may be associated with structural brain anomalies. We suggest that the simultaneous involvement of speech and emotion regulation networks might result from disrupted neural organization during development, or compensatory or maladaptive plasticity. Future studies are required to examine whether the interplay between biological trait-like diathesis (shyness, neuroticism) and the stressful experience of living with mild DFAS lead to the development of internalizing psychiatric disorders.

Loss of regional accent after damage to the speech production network.

Lesion-symptom mapping studies reveal that selective damage to one or more components of the speech production network can be associated with foreign accent syndrome, changes in regional accent (e.g., from Parisian accent to Alsatian accent), stronger regional accent, or re-emergence of a previously learned and dormant regional accent. Here, we report loss of regional accent after rapidly regressive Broca's aphasia in three Argentinean patients who had suffered unilateral or bilateral focal lesions in components of the speech production network. All patients were monolingual speakers with three different native Spanish accents (Cordobés or central, Guaranítico or northeast, and Bonaerense). Samples of speech production from the patient with native Córdoba accent were compared with previous recordings of his voice, whereas data from the patient with native Guaranítico accent were compared with speech samples from one healthy control matched for age, gender, and native accent. Speech samples from the patient with native Buenos Aires's accent were compared with data obtained from four healthy control subjects with the same accent. Analysis of speech production revealed discrete slowing in speech rate, inappropriate long pauses, and monotonous intonation. Phonemic production remained similar to those of healthy Spanish speakers, but phonetic variants peculiar to each accent (e.g., intervocalic aspiration of /s/ in Córdoba accent) were absent. While basic normal prosodic features of Spanish prosody were preserved, features intrinsic to melody of certain geographical areas (e.g., rising end F0 excursion in declarative sentences intoned with Córdoba accent) were absent. All patients were also unable to produce sentences with different emotional prosody. Brain imaging disclosed focal left hemisphere lesions involving the middle part of the motor cortex, the post-central cortex, the posterior inferior and/or middle frontal cortices, insula, anterior putamen and supplementary motor area. Our findings suggest that lesions affecting the middle part of the left motor cortex and other components of the speech production network disrupt neural processes involved in the production of regional accent features.

Repeating with the right hemisphere: reduced interactions between phonological and lexical-semantic systems in crossed aphasia?

Knowledge on the patterns of repetition amongst individuals who develop language deficits in association with right hemisphere lesions (crossed aphasia) is very limited. Available data indicate that repetition in some crossed aphasics experiencing phonological processing deficits is not heavily influenced by lexical-semantic variables (lexicality, imageability, and frequency) as is regularly reported in phonologically-impaired cases with left hemisphere damage. Moreover, in view of the fact that crossed aphasia is rare, information on the role of right cortical areas and white matter tracts underpinning language repetition deficits is scarce. In this study, repetition performance was assessed in two patients with crossed conduction aphasia and striatal/capsular vascular lesions encompassing the right arcuate fasciculus (AF) and inferior frontal-occipital fasciculus (IFOF), the temporal stem and the white matter underneath the supramarginal gyrus. Both patients showed lexicality effects repeating better words than non-words, but manipulation of other lexical-semantic variables exerted less influence on repetition performance. Imageability and frequency effects, production of meaning-based paraphrases during sentence repetition, or better performance on repeating novel sentences than overlearned clichés were hardly ever observed in these two patients. In one patient, diffusion tensor imaging disclosed damage to the right long direct segment of the AF and IFOF with relative sparing of the anterior indirect and posterior segments of the AF, together with fully developed left perisylvian white matter pathways. These findings suggest that striatal/capsular lesions extending into the right AF and IFOF in some individuals with right hemisphere language dominance are associated with atypical repetition patterns which might reflect reduced interactions between phonological and lexical-semantic processes.

Foreign accent syndrome: a multimodal evaluation in the search of neuroscience-driven treatments.

Foreign accent syndrome (FAS) is a rare condition which is placed in the mildest end of the spectrum of speech disorders. The impairment, not severe enough to elicit phonological errors, is associated with various alterations in the fine execution of speech sounds which cause the impression of foreignness. There is a growing interest in the study of linguistic and paralinguistic components, psychosocial aftermaths, and neural basis of FAS, but there are not yet neuroscience-driven treatments for this condition. A multimodal evaluation was conducted in a single patient with the aim of searching for clues which may assist to design neuroscience-driven therapies. The patient was a middle-aged bilingual woman who had chronic FAS. She had segmental deficits, abnormal production of linguistic and emotional prosody, impaired verbal communication, and reduced motivation and social engagement. Magnetic resonance imaging showed bilateral small lesions mainly affecting the left deep frontal operculum and dorsal anterior insula. Diffusion tensor tractography suggested disrupted left deep frontal operculum-anterior insula connectivity. Metabolic activity measured with positron emission tomography was primarily decreased in key components of networks implicated in planning and execution of speech production, cognitive control and emotional communication (Brodmann's areas 4/6/9/10/13/25/47, basal ganglia, and anterior cerebellar vermis). Compensatory increases of metabolic activity were found in cortical areas (left anterior cingulate gyrus, left superior temporal gyrus and right prefrontal cortex) associated with feedback and focal attention processes critical for monitoring and adjustment of verbal utterances. Moreover, bilateral structural and functional abnormalities probably interrupted the trajectory of the lateral and medial cholinergic pathways causing region-specific hypoactivity. The results from this study provide targets for further investigation and some clues to design therapeutic interventions.

From 1-word to 2-words with cochlear implant and cued speech: a case study.

This paper describes early language development in a deaf Spanish child fitted with a cochlear implant (CI) when she was 1;6 years old. The girl had been exposed to Cued Speech (CS) since that age. The main aim of the research was to identify potential areas of slow language development as well as the potential benefit of CI and CS. At the beginning of this research the child was 2;6 years (she had been using the CI for 12 months). Adult-child 30-minute sessions were videotaped every week for 1 year (13-24 months of CI use), and transcribed according to CHAT norms. Measures of phonemic inventory, intelligibility, lexicon, and grammar development were obtained. Part of the data were compared with data from two normally hearing (NH) children with the same mean length of utterance (MLU). In order to confirm trends observed during these 12 months of observation, an extra set of data was obtained in the next 3 months (25-27 months of CI use). Results in the initial 12 month period (13-24 months of CI use) showed irregular language development in the deaf child. The development of her phonemic inventory and lexicon progressed at a rate that was similar to, or faster than, that of NH children. However, the slow acquisition of articles and also the slow development of MLU suggested that the child might have problems with grammar. Data from the next 3 months (25-27 months of CI use) confirmed this trend. Results are discussed in relation to similar studies in other languages. Potential benefits of CS are also discussed.

Quantitative and qualitative evaluation of linguistic input support to a prelingually deaf child with cued speech: A case study.

This paper studies the linguistic input attended by a deaf child exposed to cued speech (CS) in the final part of her prelinguistic period (18-24 months). Subjects are the child, her mother, and her therapist. Analyses have provided data about the quantity of input directed to the child (oral input, more than 1,000 words per half-an-hour session; cued ratio, more than 60% of oral input; and attended ratio, more than 55% of oral input), its linguistic quality (lexical variety, grammatical complexity, etc.), and other properties of interaction (child attention and use of spontaneous gestures). Results show that both adults provided a rich linguistic input to the child and that the child attended most of the input that the adults cued. These results might explain the positive linguistic development of children exposed early to CS.

El desarrollo vocal en niños sordos de familias hispanohablantes / Prelinguistic vocal development and children with hearing loss who are acquiring Spanish

El desarrollo vocal es un proceso que precede a la producción de las primeras palabras; durante este proceso el niño comienza a emitir sonidos cada vez más parecidos a los del adulto, aumentando poco apoco la complejidad de las sílabas, las palabras y la variedad de los sonidos. A pesar del interés clínico de este proceso, hasta la fecha pocos estudios han examinado el desarrollo vocal en bebés de familias hispanohablantes. Este artículo representa un esfuerzo por llenar ese vacío. En él el lector encontrará un análisis de los patrones típicos de desarrollo vocal en niños de diferentes contextos lingüísticos, con especial atención al caso de los niños que aprenden español. También se presenta un procedimiento para evaluar el desarrollo vocal mediante muestras espontáneas de producción y se describe una propuesta de intervención para niños con retraso en su desarrollo vocal. Los análisis y propuestas recogidos deben ser de interés para logopedas, audiólogos, maestros de sordos y terapeutas del lenguaje infantil en general. Los autores confían que este trabajo sirva de estímulo para abordar nuevas investigaciones sobre el desarrollo vocal de niños que familias hispanohablantes (AU)

Prelinguistic vocal development is the process by which children begin to produce increasingly complex, phonetically diverse, and speech-like utterances before theysay words on a regular basis. Despite its clinical interest, few studies have explored vocal development in very young children with hearing loss who are acquiring Spanish. This article represents an effort to fill this gap. In it, the reader will find a discussion of typical patterns of development in children from different language environments, with a special emphasis on Spanish. In addition, procedures for assessing vocal development through speech sampling and an intervention approach for children with delays in vocal development are presented. This information is intended to be of use for speech-language therapists, audiologists, and teachers of deaf children, and to encourage further research into the prelinguistic and early linguistic abilities of very young children with hearing losses who come from Spanish-speaking families (AU)