A perception-induced /t/-to-/k/ sound change: evidence from a cross-linguistic study.

John Ohala claimed that the source of sound change may lie in misperceptions which can be replicated in the laboratory. We tested this claim for a historical change of /t/ to /k/ in the coda in the Southern Min dialect of Chaoshan. We conducted a forced-choice segment identification task with CVC syllables in which the final C varied across the segments [p t k ʔ] in addition to a number of further variables, including the V, which ranged across [i u a]. The results from three groups of participants whose native languages have the coda systems /p t k ʔ/ (Zhangquan), /p k ʔ/ (Chaoshan) and /p t k/ (Dutch) indicate that [t] is the least stably perceived segment overall. It is particularly disfavoured when it follows [a], where there is a bias towards [k]. We argue that this finding supports a perceptual account of the historically documented scenario whereby a change from /at/ to /ak/ preceded and triggered a more general merger of /t/ with /k/ in the coda of Chaoshan. While we grant that perceptual sound changes are not the only or even the most common type of sound change, the fact that the perception results are essentially the same across the three language groups lends credibility to Ohala's perceptually motivated sound changes.

Assessing speech intelligibility of pathological speech in sentences and word lists: The contribution of phoneme-level measures.

INTRODUCTION: Speech intelligibility is an important indicator of the degree of speech impairment in pathological speech. Articulation, as a key feature of dysarthria, has been found to be a stronger contributor to intelligibility of dysarthric speech compared to voice quality, nasality, and prosody. In fact, therapy addressing articulation is often used by speech-language pathologists. Since phoneme-level measures are more directly related to articulation, they may contribute to better evaluating articulation imprecision in speakers with dysarthria and to monitoring the effectiveness of therapy. METHOD: We collected two types of phoneme-level measures: a) Accuracy of Phonemes, the percentage of correctly transcribed phonemes, and b) Phonetic Distance, from orthographic transcriptions obtained from expert raters in two types of speech materials (i.e., meaningful sentences and word lists). We first examined the measures' interrater reliability using Generalizability Theory. Then we studied the validity of the measures by correlating them to three criterion variables. Following this, we explored their ability in distinguishing speakers in two classification tasks according to speakers' types (i.e., healthy vs dysarthric) and their severity levels of dysarthria, respectively. RESULTS: The results showed that both types of phoneme-level measures are highly reliable and valid in two different speech materials. They also showed acceptable results for both classification tasks in different speech materials, with word lists performing better than meaningful sentences. The differences between the two speech materials may be largely caused by differences in word structures and contextual cues in the materials. CONCLUSION: The results indicate that both types of phoneme-level measures show largely similar reliability and validity in both speech materials. These measures perform better in word lists than in meaningful sentences, suggesting an advantage for using word lists in clinical practice and research. On the other hand, meaningful sentences can be used for classifying healthy and dysarthric speakers. Our results suggest that using different speech materials gives a better overview of the speakers' intelligibility at the segmental level and the implications of their articulation impairments.

Assessing speech intelligibility of pathological speech: test types, ratings and transcription measures.

Speech intelligibility is an essential though complex construct in speech pathology. In this paper, we investigated the interrater reliability and validity of two types of intelligibility measures: a rating-based measure, through Visual Analogue Scales (VAS), and a transcription-based measure called Accuracy of Words (AcW), through two forms of orthographic transcriptions, one containing only existing words (EWTrans) and one allowing all sorts of words, including both existing words and pseudowords (AWTrans). Both VAS and AcW scores were collected from five expert raters. We selected speakers with various severity levels of dysarthria (SevL) and employed two types of speech materials, i.e. meaningful sentences and word lists. To measure reliability, we applied Generalizability Theory, which is relatively unknown in the field of pathological speech and language research but enables more comprehensive analyses than traditional methods, e.g., the intraclass correlation coefficient. The results convincingly indicate that five expert raters were sufficient to provide reliable rating-based (VAS) and transcription-based (AcW) measures, and that reliability increased as the number of raters or utterances increased. Generalizability Theory has proved effective in systematically dealing with reliability issues in our experimental design. We also investigated construct and concurrent validity. Construct validity was addressed by exploring the correlations between VAS and AcW within and across speech materials. Concurrent validity was addressed by exploring the correlations between our measures, i.e. VAS and AcW, and two external measures, i.e. phoneme intelligibility and SevL. The correlations corroborate the validity of VAS and AcW to assess speech intelligibility, both in sentences and word lists.

On Serendipitous Campus Meetings: A User Survey.

With campuses opening up and stimulating interactions among different campus users more and more, we aim to identify the characteristics of successful meeting places (locations) on campus. These can help practitioners such as campus managers and directors to further optimize their campus to facilitate unplanned or serendipitous meetings between academic staff and companies. A survey on three Dutch campuses, including questions on both services and locations, was analyzed both spatially and statistically using principal component (PC) and regression analysis. Four PCs were found for services (Relax, Network, Proximity and Availability) and three PCs were found for locations (Aesthetics, Cleaned and Indoor Environment). Personal characteristics as explanatory variables were not significant or only had very small effect sizes, indicating that a campus' design does not need to be tailored to certain user groups but can be effective for all. The pattern of successful locations is discussed, including the variables in each PC. These PCs provide a framework for practitioners who want to improve their campus' design to further facilitate unplanned meetings, thus contributing to cooperation between campus users, hopefully leading to further innovation.

Increased rate of respiratory symptoms in children with Down syndrome: a 2-year web-based parent-reported prospective study.

To compare the incidence of respiratory symptoms and short-term consequences between children with Down syndrome and children from the general population, we conducted a prospective parent-reported observational study. Children with Down syndrome (≤ 18 years) were included between March 2012 and June 2014. Caregivers received a baseline questionnaire with follow-up 1-2 years after inclusion. Caregivers received a weekly questionnaire about respiratory symptoms, fever, antibiotic prescriptions, doctor's visits, and consequences for school and work attendance. Children with Down syndrome were compared to a cohort of the general population ("Kind en Ziek" study) with similar weekly questionnaires. A total of 9,011 childweeks were reported for 116 participants with Down syndrome (75% response rate). The frequency of respiratory symptoms was higher in children with Down syndrome than in children from the general population (30% vs 15.2%). In addition, symptoms subsided later (around 8 vs 5 years of age). The seasonal influence was limited, both in children with Down syndrome and children from the general population. Consequences of respiratory disease were significant in children with Down syndrome compared to children from the general population, with a higher rate of doctor's visits (21.3% vs 11.8%), antibiotic prescriptions (47.8% vs 26.3%), and absenteeism from school (55.5% vs 25.4%) and work (parents, 9.4% vs 8.1%).  Conclusion: Children with Down syndrome have a higher frequency of respiratory symptoms and symptoms last until a later age, confirming the impression of professionals and caregivers. Individualized treatment plans might prevent unfavorable consequences of chronic recurrent respiratory disease in children with Down syndrome. What is Known: • Children with Down syndrome have an altered immune system and are prone to a more severe course of respiratory tract infections. • The overall conception is that patients with Down syndrome suffer from respiratory tract infections more often. What is New: • Children with Down syndrome suffer from respiratory symptoms more frequently than children from the general population. • The respiratory symptoms in children with Down syndrome subside at a later age compared to children from the general population.

Linking Linguistic and Geographic Distance in Four Semantic Domains: Computational Geo-Analyses of Internal and External Factors in a Dialect Continuum.

Dialectometry studies patterns of linguistic variation through correlations between geographic and aggregate measures of linguistic distance. However, aggregating smooths out the role of semantic characteristics, which have been shown to affect the distribution of lexical variants across dialects. Furthermore, although dialectologists have always been well-aware of other variables like population size, isolation and socio-demographic features, these characteristics are generally only included in dialectometric analyses afterwards for further interpretation of the results rather than as explanatory variables. This study showcases linear mixed-effects modelling as a method that is able to incorporate both language-external and language-internal factors as explanatory variables of linguistic variation in the Limburgish dialect continuum in Belgium and the Netherlands. Covering four semantic domains that vary in their degree of basic vs. cultural vocabulary and their degree of standardization, the study models linguistic distances using a combination of external (e.g., geographic distance, separation by water, population size) and internal (semantic density, salience) sources of variation. The results show that both external and internal factors contribute to variation, but that the exact role of each individual factor differs across semantic domains. These findings highlight the need to incorporate language-internal factors in studies on variation, as well as a need for more comprehensive analysis tools to help better understand its patterns.

Where does a 'foreign' accent matter? German, Spanish and Singaporean listeners' reactions to Dutch-accented English, and standard British and American English accents.

How well L2 English is understood and how L2 English speakers perceive one another within varying communication contexts has been studied relatively rarely, even though most speakers of English in the world are L2 speakers. In this matched-guise experiment (N = 1699) the effects of L1 and L2 English accents and communication context were tested on speech understandability (intelligibility, comprehensibility, interpretability) and speaker evaluations (status, affect, dynamism). German (N = 617), Spanish (N = 540), and Singaporean listeners (N = 542) were asked to evaluate three accents (Dutch-accented English, standard British English, standard American English) in three communication contexts (Lecture, Audio Tour, Job Pitch). The main finding is that the Dutch-accented English accent was understood as well as the two L1 English accents. Furthermore, Dutch-accented English evoked equally positive evaluations to the two L1 English accents in German listeners, and more positive evaluations than the two L1 English accents in Spanish and Singaporean listeners. These results suggest that accent training aimed at achieving an L1 English accent may not always be necessary for (Dutch) English language learners, especially when they are expected to mostly interact with other L2 speakers of English. More generally, our results indicate that L2 English speakers' understanding and their evaluation of L1 and L2 Englishes would not seem to reflect traditional language norms. Instead, they seem to reflect the socio-cultural embedding of a language norm in a Lingua Franca English speech community that does not view accent varieties as a hindrance to successful communication.

Respiratory Symptoms in Post-infancy Children. A Dutch Pediatric Cohort Study.

Aim: To study the pattern of respiratory symptoms in children in the general population. Method: We followed a cohort of children for up to 2 years through parents completing weekly online questionnaires in the Child-Is-Ill study ("Kind-en-Ziekmeting" in Dutch); the study was running 2012-2015. Inclusion criteria were "an ordinary child" (according to the parents) and <18 years old at inclusion. We especially encouraged participation of post-infancy children. Age at inclusion, sex, smoking exposure, allergy in the family, and frequent infections in the family were noted. Pearson's correlation, principal component analysis, latent class analysis, latent profile analysis, linear regression, and linear mixed effects regression were used in the statistical analyses. Results: Data were collected on 55,524 childweeks in 755 children (50% girls; median age, 7 years; interquartile range, 4-11 years, 97% ≥2 years at inclusion), with reported symptom(s) in 8,425 childweeks (15%), leading to school absenteeism in 25%, doctor's visits in 12%, and parental sick leave in 8%; symptoms lasting ≥3 weeks were rare (2% of episodes). Linear mixed effects regression showed significant, but only limited, effects of season on the proportion of "symptom(s) reported" per individual child. Only runny nose showed a significant, but very small, age effect. However, the variability between the children was considerable. There were no obvious subgroups of children with specific symptom combinations. Conclusion: In any randomly chosen week, the vast majority of children (85%) in our-mainly-post-infancy cohort derived from the general population did not have any symptom, even in the younger age group, even in winter. The children showed considerable variability; no clear subgroups of symptom patterns could be identified, underlining the difficult position of healthcare providers. These results support our opinion that post-infancy children in the general population should not be evaluated as if they are infants when they have recurrent respiratory symptoms. If they clearly deviate from the above-described most common pattern, it is wise to keep an eye on potential, maybe even rare, serious underlying causes.

Big data suggest strong constraints of linguistic similarity on adult language learning.

When adults learn new languages, their speech often remains noticeably non-native even after years of exposure. These non-native variants ('accents') can have far-reaching socio-economic consequences for learners. Many factors have been found to contribute to a learners' proficiency in the new language. Here we examine a factor that is outside of the control of the learner, linguistic similarities between the learner's native language (L1) and the new language (Ln). We analyze the (open access) speaking proficiencies of about 50,000 Ln learners of Dutch with 62 diverse L1s. We find that a learner's L1 accounts for 9-22% of the variance in Ln speaking proficiency. This corresponds to 28-69% of the variance explained by a model with controls for other factors known to affect language learning, such as education, age of acquisition and length of exposure. We also find that almost 80% of the effect of L1 can be explained by combining measures of phonological, morphological, and lexical similarity between the L1 and the Ln. These results highlight the constraints that a learner's native language imposes on language learning, and inform theories of L1-to-Ln transfer during Ln learning and use. As predicted by some proposals, we also find that L1-Ln phonological similarity is better captured when subcategorical properties (phonological features) are considered in the calculation of phonological similarities.

The geographical configuration of a language area influences linguistic diversity.

Like the transfer of genetic variation through gene flow, language changes constantly as a result of its use in human interaction. Contact between speakers is most likely to happen when they are close in space, time, and social setting. Here, we investigated the role of geographical configuration in this process by studying linguistic diversity in Japan, which comprises a large connected mainland (less isolation, more potential contact) and smaller island clusters of the Ryukyuan archipelago (more isolation, less potential contact). We quantified linguistic diversity using dialectometric methods, and performed regression analyses to assess the extent to which distance in space and time predict contemporary linguistic diversity. We found that language diversity in general increases as geographic distance increases and as time passes-as with biodiversity. Moreover, we found that (I) for mainland languages, linguistic diversity is most strongly related to geographic distance-a so-called isolation-by-distance pattern, and that (II) for island languages, linguistic diversity reflects the time since varieties separated and diverged-an isolation-by-colonisation pattern. Together, these results confirm previous findings that (linguistic) diversity is shaped by distance, but also goes beyond this by demonstrating the critical role of geographic configuration.

Challenges in investigating patients with isolated decreased serum IgM: The SIMcal study.

The clinical consequences of isolated decreased serum immunoglobulin (Ig)M are not sufficiently known. Therefore, it is difficult to determine the clinical policy following such a finding. Only few reported IgM-deficient patients fulfil the European Society for Immunodeficiencies (ESID) diagnostic criteria for selective IgM deficiency (true sIgMdef), or their diagnosis is uncertain due to insufficient laboratory data (possible sIgMdef). Decreased serum IgM is often incidentally found in asymptomatic adults. The objective of our study was to further characterize true sIgMdef and to compare the European data collected through the ESID Registry community (tertiary centres) to our previously published Dutch cohort (secondary centre). Fifteen centres (12 countries) participated with 98 patients. Patients were excluded if serum IgM was only determined once (n = 14), had normalized (n = 8), or if they also had other immunological abnormalities (n = 15). Ten patients (5 adults) completely fulfilled the ESID criteria for true sIgMdef. Age-matched cut-off values varied widely between centres; when using the ESID diagnostic protocol reference values, only six patients (five adults) had true sIgMdef. Because of these small numbers, further analyses were performed in patients with true or possible sIgMdef (13 adults, 48 children). Respiratory infections were commonly reported at presentation (adults 54%, children 60%). Symptomatic adults had lower serum IgM levels (mean 0.27 g/L, 95% CI 0.22-0.31) than those without symptoms (mean 0.33 g/L, 95% CI 0.30-0.36; P = 0.02). To be able to explore the clinical consequences of true sIgMdef, we should fully analyse and accurately describe those patients in whom a decreased serum IgM is found.

Talker-familiarity benefit in non-native recognition memory and word identification: The role of listening conditions and proficiency.

Native listeners benefit from talker familiarity in recognition memory and word identification, especially in adverse listening conditions. The present study addresses the talker familiarity benefit in non-native listening, and the role of listening conditions and listeners' lexical proficiency in the emergence of this benefit. Dutch non-native listeners of English were trained to identify four English talkers over 4 days. Talker familiarity benefit in recognition memory was investigated using a recognition memory task with "old" and "new" words produced by familiar and unfamiliar talkers presented either in the clear or in noise. Talker familiarity benefit in word identification was investigated by comparing non-native listeners' performances on the first and the last day in identifying words in different noise levels, produced by either a trained (included in the voice recognition training) or by an untrained talker (not included in the voice recognition training). Non-native listeners demonstrated a talker familiarity benefit in recognition memory, which was modulated by listening conditions and proficiency in the non-native language. No talker familiarity benefit was found in word identification. These results suggest that, similar to native listening, both linguistic and indexical (talker-specific) information influence non-native speech perception. However, this is dependent on the task and type of speech recognition process involved.

Language balance and switching ability in children acquiring English as a second language.

This study investigated whether relative lexical proficiency in Dutch and English in child second language (L2) learners is related to executive functioning. Participants were Dutch primary school pupils of three different age groups (4-5, 8-9, and 11-12 years) who either were enrolled in an early-English schooling program or were age-matched controls not on that early-English program. Participants performed tasks that measured switching, inhibition, and working memory. Early-English program pupils had greater knowledge of English vocabulary and more balanced Dutch-English lexicons. In both groups, lexical balance, a ratio measure obtained by dividing vocabulary scores in English by those in Dutch, was related to switching but not to inhibition or working memory performance. These results show that for children who are learning an L2 in an instructional setting, and for whom managing two languages is not yet an automatized process, language balance may be more important than L2 proficiency in influencing the relation between childhood bilingualism and switching abilities.

The effect of background noise on the word activation process in nonnative spoken-word recognition.

This article investigates 2 questions: (1) does the presence of background noise lead to a differential increase in the number of simultaneously activated candidate words in native and nonnative listening? And (2) do individual differences in listeners' cognitive and linguistic abilities explain the differential effect of background noise on (non-)native speech recognition? English and Dutch students participated in an English word recognition experiment, in which either a word's onset or offset was masked by noise. The native listeners outperformed the nonnative listeners in all listening conditions. Importantly, however, the effect of noise on the multiple activation process was found to be remarkably similar in native and nonnative listening. The presence of noise increased the set of candidate words considered for recognition in both native and nonnative listening. The results indicate that the observed performance differences between the English and Dutch listeners should not be primarily attributed to a differential effect of noise, but rather to the difference between native and nonnative listening. Additional analyses showed that word-initial information was found to be more important than word-final information during spoken-word recognition. When word-initial information was no longer reliably available word recognition accuracy dropped and word frequency information could no longer be used suggesting that word frequency information is strongly tied to the onset of words and the earliest moments of lexical access. Proficiency and inhibition ability were found to influence nonnative spoken-word recognition in noise, with a higher proficiency in the nonnative language and worse inhibition ability leading to improved recognition performance. (PsycINFO Database Record

L2 voice recognition: The role of speaker-, listener-, and stimulus-related factors.

Previous studies examined various factors influencing voice recognition and learning with mixed results. The present study investigates the separate and combined contribution of these various speaker-, stimulus-, and listener-related factors to voice recognition. Dutch listeners, with arguably incomplete phonological and lexical knowledge in the target language, English, learned to recognize the voice of four native English speakers, speaking in English, during four-day training. Training was successful and listeners' accuracy was shown to be influenced by the acoustic characteristics of speakers and the sound composition of the words used in the training, but not by lexical frequency of the words, nor the lexical knowledge of the listeners or their phonological aptitude. Although not conclusive, listeners with a lower working memory capacity seemed to be slower in learning voices than listeners with a higher working memory capacity. The results reveal that speaker-related, listener-related, and stimulus-related factors accumulate in voice recognition, while lexical information turns out not to play a role in successful voice learning and recognition. This implies that voice recognition operates at the prelexical processing level.

The paired t test and beyond: Recommendations for testing the central tendencies of two paired samples in research on speech, language and hearing pathology.

PURPOSE: In this tutorial we review current practice in the analysis of data obtained in designs involving two dependent samples and evaluate two conventional statistics: the t test for paired samples and its non-parametric alternative, the Wilcoxon Signed Ranks test (WSR). It is a sequel to our tutorial on the analysis of designs with two independent samples on the basis of non-count data (Rietveld & van Hout, 2015). The frequency with which these statistics are used is assessed on the basis of publications on disordered communication in Clinical Linguistics & Phonetics, Journal of Communication Disorders and Journal of Speech, Language and Hearing Research for the time interval 2006-2015. We conclude with a number of recommendations for the analysis and presentation of data. CONCLUSIONS: Researchers should more consistently present the relevant characteristics of their data (means, medians, SD, skewness, tailedness, outliers etc.) and explicitly consider the assumptions that apply to their statistical methods, such as correlations between data obtained on two occasions, interactions between participants and treatment, and the symmetry of difference scores, many of which are hardly ever reported or even tested. Two recommendations are particularly relevant. First, the WSR is not a proper test for central tendencies as a replacement of the conventional t test for paired samples whenever assumptions about the dependent variable are in doubt. Second, researchers should choose statistical procedures on the basis of the null hypothesis (H0) to be tested and not primarily on the basis of the type of data (ordinal or interval). Two relevant H0's in the field of speech-language pathology are: (1) µ1=µ2 (the mean obtained in condition 1 is equal to the mean in condition 2) and (2) p=0.5, which says: the probability to obtain (for instance) higher scores in condition 2 than in condition 1 is 0.5. We recommend the permuted t test for paired samples to test the first H0 and the permuted Brunner-Munzel rank test to test the second.

The Challenge of Immunoglobulin-G Subclass Deficiency and Specific Polysaccharide Antibody Deficiency--a Dutch Pediatric Cohort Study.

PURPOSE: Immunoglobulin(Ig)G-subclass deficiency and specific polysaccharide antibody deficiency (SPAD) are among the most frequent causes of recurrent respiratory infections in children. Little is known about their prevalence, clinical presentation and prognosis. No study has been published in a Western-European nor in a mainly non-tertiary cohort until now. Therefore, we performed this observational cohort study in children recruited from secondary and tertiary pediatric practices all over The Netherlands. METHODS: Dutch pediatricians were monthly asked to report patients with IgG-subclass deficiency and/or SPAD. Demographic, clinical and laboratory characteristics were collected. Separate informed consent was asked from parents and children (≥ 12 years of age) for annual update of the medical status. RESULTS: 49 children with confirmed IgG-subclass deficiency and/or SPAD were included. The majority of children (69%) was reported by four (out of 12) secondary hospitals with a pediatric immunologist in the staff. 45 children had ≥ 1 low IgG-subclass level and 11 had SPAD. IgG2 deficiency was the most prevalent IgG-subclass deficiency (37/49;76%). 10% of these children already showed bronchiectasis. Two-thirds were male (33/49;67%, p = 0.015). From 10 years of age, only boys were left and only boys showed progressive immunodeficiency during follow-up (11/24; 46%). CONCLUSIONS: This is the first Western-European mainly non-tertiary cohort of children with IgG-subclass deficiency and/or SPAD. The disease course is not always benign, especially in boys. Most children were reported and managed in secondary hospitals with a pediatric immunologist in the staff. To identify more patients, the awareness of these diseases among general pediatricians should increase.

The Gender Gap in Second Language Acquisition: Gender Differences in the Acquisition of Dutch among Immigrants from 88 Countries with 49 Mother Tongues.

Gender differences were analyzed across countries of origin and continents, and across mother tongues and language families, using a large-scale database, containing information on 27,119 adult learners of Dutch as a second language. Female learners consistently outperformed male learners in speaking and writing proficiency in Dutch as a second language. This gender gap remained remarkably robust and constant when other learner characteristics were taken into account, such as education, age of arrival, length of residence and hours studying Dutch. For reading and listening skills in Dutch, no gender gap was found. In addition, we found a general gender by education effect for all four language skills in Dutch for speaking, writing, reading, and listening. Female language learners turned out to profit more from higher educational training than male learners do in adult second language acquisition. These findings do not seem to match nurture-oriented explanatory frameworks based for instance on a human capital approach or gender-specific acculturation processes. Rather, they seem to corroborate a nature-based, gene-environment correlational framework in which language proficiency being a genetically-influenced ability interacting with environmental factors such as motivation, orientation, education, and learner strategies that still mediate between endowment and acquiring language proficiency at an adult stage.

The t test and beyond: Recommendations for testing the central tendencies of two independent samples in research on speech, language and hearing pathology.

PURPOSE: In this Tutorial we compare current practice of the analysis of data obtained in designs involving two independent samples with new developments in statistics and evidence on the behavior of conventional statistics. We included t tests, non-parametric alternatives, such as the Wilcoxon-Mann-Whitney test, and recently developed approaches, known as bootstrapping and randomization tests. The relative use of the different statistics is illustrated on the basis of counts carried out in three journals on disordered communication in the time interval 2005-2013: Clinical Linguistics & Phonetics, Journal of Communication Disorders and Journal of Speech, Language and Hearing Research. A number of recommendations are given to guide the researcher in the presentation and analysis of her/his data. CONCLUSIONS: The main messages are (a) that researchers should present more relevant features of their data (means, medians, SD, skewness, tailedness, outliers etc.), (b) not routinely use conventional non-parametric tests like Wilcoxon-Mann-Whitney test in case one or more of the assumptions of t tests are not met, and (c) should consider using less conventional, but robust statistics which have been developed and tested in the last decades.

Epidemiology of respiratory symptoms in children with Down syndrome: a nationwide prospective web-based parent-reported study.

BACKGROUND: Children with Down syndrome suffer from recurrent respiratory tract and ear-nose-throat complaints that influence daily life. Little is known about the frequency of these complaints, as well as their relation to co-morbidity and ageing. METHODS/DESIGN: A prospective web-based parent-reported observational study was designed for parents having a child with Down syndrome (age 0 to 18 years). Upon registration, parents receive an email containing a link to a weekly questionnaire regarding respiratory symptoms during two consecutive years. Additionally, at the beginning, after one year and at the end of the study they receive an extended questionnaire concerning baseline data, daily activities and medical history. The data will be compared to the ongoing "child-is-ill" study, which collects weekly data in an identical fashion in children that are considered to be "normal as to being ill" by their parents. DISCUSSION: This study will provide important data on the epidemiology of respiratory symptoms in children with Down syndrome, which will be useful for further studies on treatment options. Also, this study will gain insight in healthcare usage and work absence due to the child's illnesses.