Large gaps exist in understanding the symptomatic and functional impact of sarcoidosis, a rare multisystem granulomatous disease affecting fewer than 200,000 individuals in the United States. Smartphones could be used for prospective research, especially for rare diseases where organizing large cohorts can be challenging, given their near ubiquitous ownership and ability to track objective and subjective data with increasingly sophisticated technology.We aimed to investigate whether smartphones could assess the quality of life (QoL) and physical activity of a large cohort of individuals with sarcoidosis.We developed a mobile app (Sarcoidosis App) for a prospective, cross-sectional study on individuals with sarcoidosis. The Sarcoidosis App was made available on both Apple and Android smartphones. Individuals with sarcoidosis were recruited, consented, and enrolled entirely within the app. Surveys on sarcoidosis history, medical history, and medications were administered. Patients completed modules from the Sarcoidosis Assessment Tool, a validated patient-reported outcomes assessment of physical activity, fatigue, pain, skin symptoms, sleep, and lungs symptoms. Physical activity measured by smartphones was tracked as available.P<.001, ρ=0.250) and fatigue  correlated with actual smartphone-tracked physical activity. Overall, 19.0% (98/517) of participants missed at least 1 week of school or work in an observed month owing to sarcoidosis, and 44.4% (279/629) reported that finances “greatly” or “severely” affected by sarcoidosis. Furthermore, 71.2% (437/614) of participants reported taking medications for sarcoidosis, with the most common being prednisone, methotrexate, hydroxychloroquine, and infliximab. Moreover, 46.4% (244/526) reported medication side effects, most commonly due to prednisone.From April 2018 to May 2020, the App was downloaded 2558 times, and 629 individuals enrolled . Two-thirds of participants had a college or graduate degree, and more than half of them reported an income greater than US $60,000. Both QoL related to physical activity (We demonstrate that smartphones can prospectively recruit, consent, and study physical activity, QoL, and medication usage in a large sarcoidosis cohort, using both passively collected objective data and qualitative surveys that did not require any in-person encounters. Our study’s limitations include the study population being weighted toward more educated and wealthier individuals, suggesting that recruitment was not representative of the full spectrum of patients with sarcoidosis in the United States. Our study provides a model for future smartphone-enabled clinical research for rare diseases and highlights key technical challenges that future research teams interested in smartphone-based research for rare diseases should anticipate. Sarcoidosis is a multisystem granulomatous disease that most commonly affects the lungs, skin, eyes, and lymph nodes. In the United States, over 185,000 patients with sarcoidosis seek medical care annually, and 25,000 new cases of sarcoidosis are diagnosed [Sarcoidosis is a rare disease, which is defined as affecting fewer than 200,000 individuals. Clinical research of rare diseases is challenging—nearly one-third of rare disease clinical trials are discontinued with insufficient patient accrual being the most common reason . Large cThe goal of our study was to develop and launch a smartphone app to assess patient-reported quality of life (QoL) in a large population of patients with sarcoidosis and to characterize patients’ symptomatology and functional status. We designed this app to describe physical activity and correlate physical activity data with self-reported characteristics through QoL surveys, medication use, and adverse effects and comorbidities. Here, we describe the development and launch of the app and present results from the surveys and physical activity data collected from patients.The Sarcoidosis App , developPatients with sarcoidosis were recruited via outpatient dermatology clinic visits at the University of Pennsylvania Health System, the Foundation for Sarcoidosis Research mailing list, and targeted social media advertisements. After prospective participants downloaded the app, they were presented with an inclusion and exclusion criteria questionnaire to provide multiple means of participant recruitment. Participants were eligible for study enrollment if they were aged greater than 18 years, lived in the United States, and self-reported a diagnosis of sarcoidosis. Participants were asked for permission to enable the app to read HealthKit or Google Fit data. To ensure participants understood the risks, benefits, and options of study participation, they were required to pass a quiz concerning these issues before digitally signing the informed consent document .The Sarcoidosis App administered baseline surveys of (1) sarcoidosis history, (2) pertinent medical history, (3) sarcoidosis treatment medications, and (4) items from modules of the Sarcoidosis Assessment Tool (SAT). The SAT is a validated patient-reported assessment that comprises select generic measures from the Patient-Reported Outcomes Measurement Information System, as well as several sarcoidosis-specific item banks, including physical functioning, satisfaction with roles and activities, fatigue, pain interference, sleep disturbance, lung concerns, skin concerns, and skin stigma and embarrassment . After tDescriptive statistics were calculated for demographic information, patient-reported outcomes, and physical activity data. Missing data were excluded from analyses except where described. Spearman correlation coefficients were calculated for correlating responses to the SAT modules for physical activity, lungs, and fatigue with average daily steps and traveled distance from smartphone-recorded data, as much of the survey and physical activity measures were not normally distributed. In addition, the use of ranks through Spearman correlation diminishes the influence of outliers in some of the physical activity measures. All statistics were calculated using Stata  and R . The survey data and physical activity data used in this study is available upon reasonable request to BC and MR.This study was approved by the institutional review board of the University of Pennsylvania (824080). This paper adheres to STROBE  reporting guidelines. Participants who met eligibility criteria proceeded to provide electronic informed consent.From April 2018 to May 2020, the app was downloaded 2558 times: 1603 from the Apple App Store and 955 from Google Play. A quarter (629/2558) of downloads converted to study participation, with 629 unique participants completing at least one component of the background survey concerning basic demographic data . Of themIn total, 597 unique participants filled out at least one of the SAT modules. The mean scores of each SAT module and their SDs are reported in Where data were available for both SAT survey responses and device-measured physical activity, correlational analyses were performed. SAT physical activity scores positively correlated with average daily steps (n=226), and SAT fatigue scores negatively correlated with average daily steps (n=245) . SAT lunMedical resource usage was assessed among 517 unique participants who completed at least one question of an initial survey . OverallIn total, 614 unique participants completed at least one question from the baseline medication survey . OverallParticipants were also asked to complete a survey concerning medication adverse effects within the prior month . OverallIn this study, we demonstrate the novel use of smartphones to prospectively recruit, consent, and study physical activity and QoL in a large cohort of individuals with sarcoidosis, using both objective health tracking data and qualitative survey responses. We were able to demonstrate a strong correlation between the assessment of physical state and the activity level of participants with sarcoidosis, measured by smartphone apps. Specifically, participants who were more active, as measured by daily steps and distance traveled as tracked by their smartphones, also had physical activity and fatigue scores, representing a smaller impact of their disease on these domains on the SAT—a previously-defined patient-reported QoL metric . Nearly The findings of this study suggest that smartphone technology may have advantages in the conduct of prospective clinical research in sarcoidosis and other rare diseases, though robust human and technical resources are critical. First, these data suggest smartphones have potential to enroll patients with sarcoidosis in clinical trials and reliably assess them without requiring a traditional in-person clinic visit. In this way, the clinical research study can be brought directly to participants, bypassing financial and geographic barriers of many socially disadvantaged patients with sarcoidosis, who are often unrepresented in clinical trials. However, these methods cannot replace studies that require laboratory testing or imaging. Second, as these assessments can be made in real time without investigator prompting, this method may avoid significant recall bias and investigator influence respectively. Third, the capability of integrating objective health tracking data with subjective survey data offers a multidimensional assessment of patients with sarcoidosis. In this way, studies using smartphones could provide alternative channels of demonstrating construct validity of patient-reported outcomes.The strengths of our study were tempered by the technical challenges of developing and maintaining a mobile app. Clinical research teams without strong technical experience will encounter many obstacles in designing and launching mobile apps, and partnerships with technology companies are essential to the success of these projects. However, lack of cross-disciplinary understanding presents substantial challenges to meaningful collaboration with external stakeholders; clinical research teams may not even be able to envision what is technically possible, and developers may lack perspective on how these products are actually delivered to patients . Even wiThere were several limitations regarding the background of participants. First, individuals self-reported a diagnosis of sarcoidosis, which introduces the possibility of participants without a true diagnosis, even though participants were recruited directly from sarcoidosis clinics and advocacy groups for patients with sarcoidosis. Another limitation of our study is that our study population was weighted toward more educated and wealthier individuals. It is possible that the rate of response and familiarity with smartphone apps in our cohort was not representative of the full population of patients with sarcoidosis in the United States, particularly older individuals and those with low technology literacy. Future mobile app studies of sarcoidosis and other rare diseases should prioritize recruiting from a diverse set of sarcoidosis clinics that would provide a more representative sample, in addition to patient advocacy groups. Given that sarcoidosis results in disparate outcomes by race, sex, and socioeconomic class  and an aFuture apps could also integrate environmental data, such as location, weather, and air quality to provide additional dimensions of analysis. Wearable devices, such as smartwatches, can also provide valuable data, though ownership is not as prevalent. Beyond observational research, smartphones also present opportunities for digital therapeutics, which are evidence-based interventions driven by software. For example, one group has demonstrated that a smartphone-based stress management tool significantly reduced stress and fatigue in patients with sarcoidosis compared to control patients . In an e


Prosodic features are important in achieving intelligibility, comprehensibility, and fluency in a second or foreign language (L2). However, research on the assessment of prosody as part of oral proficiency remains scarce. Moreover, the acoustic analysis of L2 prosody has often focused on fluency-related temporal measures, neglecting language-dependent stress features that can be quantified in terms of syllable prominence. Introducing the evaluation of prominence-related measures can be of use in developing both teaching and assessment of L2 speaking skills. In this study we compare temporal measures and syllable prominence estimates as predictors of prosodic proficiency in non-native speakers of English with respect to the speaker’s native language (L1).The predictive power of temporal and prominence measures was evaluated for utterance-sized samples produced by language learners from four different L1 backgrounds: Czech, Slovak, Polish, and Hungarian. Firstly, the speech samples were assessed using the revised Common European Framework of Reference scale for prosodic features. The assessed speech samples were then analyzed to derive articulation rate and three fluency measures. Syllable-level prominence was estimated by a continuous wavelet transform analysis using combinations of F0, energy, and syllable duration.The results show that the temporal measures serve as reliable predictors of prosodic proficiency in the L2, with prominence measures providing a small but significant improvement to prosodic proficiency predictions. The predictive power of the individual measures varies both quantitatively and qualitatively depending on the L1 of the speaker. We conclude that the possible effects of the speaker’s L1 on the production of L2 prosody in terms of temporal features as well as syllable prominence deserve more attention in applied research and developing teaching and assessment methods for spoken L2. While the well-known language learning theories have focused on the segmental aspects of pronunciation . Oral L2 proficiency includes many facets, but a core skill in spoken communication is pronunciation on both segmental  and suprasegmental or nciation , prosodynciation . ProsodiSince the prosodic systems of languages differ substantially , languagIn this study, we investigate prosodic features as predictors of L2 English speaking proficiency from two perspectives: measuring temporal features related to fluency, and comparing syllable-level stress realizations of native and L2 speakers. The focus of the paper is on the comparison of the two methods in predicting assessments of prosodic proficiency. In addition, we examine the L2 speech of learners with four different L1 backgrounds: Czech, Slovak, Polish, and Hungarian. The current set of languages differs from that in previous research with respect to typological distance, which broadens the research scope of L1 effects on L2 speech to more fine-grained acoustic differences that remain invisible when studying typologically very distant languages. In the current study, we are interested in whether prominence as an acoustic realization of stress and a local aspect of prosody can predict L2 learners’ oral proficiency better than traditionally used temporal measures, and whether speakers’ L1s play a role in proficiency assessments in spite of the relative closeness of the L1s.L2 prosody has generally been studied from the perspectives of foreign accent and/or fluency . Prosodispeed fluency, referring to the speed at which speech is delivered ; (2) breakdown fluency, referring to pausing phenomena ; and (3) repair fluency, referring to false starts, corrections, and repetitions .Fluency is one of the most commonly used terms in language pedagogy and testing and it is generally included in many assessment criteria of oral L2 skills, such as the Common European Framework of Reference (CEFR) for languages , Internapausing as well as articulation rate. speech rate, mean length of utterance, phonation–time ratio, and number of stressed words produced per minute to be the best predictors of fluency ratings. speech rate was the best predictor of fluency scores in both speech types, especially for the beginner level, while articulation rate had a strong correlation with perceived fluency in read speech but not in spontaneous speech. filled and silent pauses and the mean length of pause together with the mean length of syllable are significant predictors of fluency ratings. the mean length of runs (a combination of speed and breakdown features) and articulation rate were better predictors of perceived fluency than pause measures.Many phonetic studies have used measures related to these components, and measures of speed and breakdown fluency in particular have been found to correlate with fluency assessments. The findings provide, however, a somewhat inconsistent picture: The diversity of these results can be attributed to different conceptualizations and operationalizations of fluency and its measures as well as to the different types of analyzed data. There are, for example, some inconsistencies in defining pauses: depending on the study and speech material, the pause threshold ranges from 50 ms to as long as 3 s , which cSome disfluencies occur differently depending on the context. Filled pauses are generally more typical for spontaneous speech than read speech, but the use of pauses can also be a language-specific phenomenon; for example, prominence to make it stand out acoustically and perceptually. Languages differ in both the positioning and acoustic realization of stress  of prosodic features. The method has been shown to provide strong correlations with perceptual prominence  as well This study investigates the temporal features and syllable prominence of L2 English produced by speakers with either Czech, Slovak, Hungarian, or Polish as a L1. Czech, Slovak, and Polish are West-Slavic Indo-European languages, while Hungarian belongs to the Finno-Ugric branch of the Uralic language family. However, Czech, Slovak, and Hungarian share a number of prosodic characteristics and other linguistic features, which have been hypothesized to stem from historical convergence as well as direct linguistic influence . The speThe difficulties that the English stress system has posed to language learners have been noted in various sources . RegardiThe primary prosodic feature signaling prominence in English is said to be duration: stressed syllables in English are considerably longer than unstressed syllables, and F0 and intensity remain contributing markers of stress . HungariWhile in Hungarian F0 patterns have been assumed to be determined primarily by sentence information structure , Vogel eRelatively few studies have been done on the production of English stress patterns by speakers of Czech, Slovak, Hungarian, and Polish . For HunIn English, the contrast between stressed and unstressed syllables is manifested relatively strongly, often resulting in reduction of the unstressed vowels to a schwa . In CzecIn addition to lexical stress, prominence patterns also arise from temporally wider prosodic phenomena, such as sentence stress. In English, the most prominent part of a phrase (without a specific focus condition) is usually in the final position, and elements before sentence stress are prosodically reduced . HoweverThe acoustic analysis of sentence stress often focuses on finding the F0 peaks in a phrase, but the contributions of intensity and duration have also received attention. In a study by To conclude, the fixed word order in English permits the placement of sentence stress to vary more than in other languages in this study, which may inhibit the functional use of sentence stress in non-native speakers of English. However, language-specific characteristics in the realization of sentence stress can also result in differing manifestations regarding both prominence and overall temporal features in L2 speech.The main objective of this study is to compare fluency-related temporal measures and CWT-based continuous syllable prominence estimates as predictors of L2 prosodic proficiency with respect to a speaker’s L1. The research questions that the current study aims to address are as follows.(RQ1) Can temporal measures be used to predict prosodic proficiency assessments of L2 speakers from different L1 backgrounds?(RQ2) Can syllable-level prominence realizations be used in predicting the same prosodic proficiency assessments?(RQ3) How do the two methods complement each other?To answer RQ1, we study the effect of various temporal measures and their interactions with speakers’ L1s on prosodic proficiency assessments using statistical models designed for ordered categorical data. In order to address RQ2, we calculate correlations between syllable-level prominence estimates for sentences produced by L1 and L2 speakers, and evaluate the potential influence of the speaker’s L1 on the relationship between these prominence-based measures and assessment grades. To answer RQ3, we compare statistical models with temporal measures and CWT-based syllable prominence estimates as predictors of prosodic proficiency.We expect both methods to be applicable for distinguishing speakers with different proficiency levels, following the findings of With regard to the CWT-based method, we expect the salience of different prosodic characteristics  to be language-dependent in prominence production and, therefore, the local prominence measures to reveal differences arising from language-specific acoustic realizations of lexical and phrasal stress. Based on our previous findings , the besN = 14), Czech (N = 14), Polish (N = 17), or Hungarian (N = 16) as their L1 were previously recorded in these universities. Each university aimed at recruiting participants with differing levels of English skills, but the overall proficiency levels of the L2 speakers were not systematically controlled for prior to recording of the material.The speech data used in this study was provided by four universities: Constantine the Philosopher University in Nitra, Slovakia; Metropolitan University Prague, Czech Republic; University of Łódz, Poland; and the Hungarian Academy of Sciences. Adult learners of English with Slovak  speaker, one as an intermediate level (B1), and one as a proficient speaker (C1/C2). Since the proficiency levels were not originally balanced between the L1 groups, the authors did not want to interfere with the proficiency distributions of the groups. This method was also considered less likely to cause bias than excluding samples randomly due to the relatively small number of speakers in the group . The proficiency levels used here are based on the CEFR for languages , which iIn order to compare the prominence realizations between L1 and L2 speakers, data from seven native speakers of English were recorded in a soundproof studio in Constantine the Philosopher University in Nitra reading the same narrative as previously recorded L2 speakers. Five  speakers were native speakers of British English and two  were native speakers of American English.The recordings were done one participant at a time using either a recording studio or some other quiet space with a portable recording device. All participants were given at least 2 min to get acquainted with the text and the opportunity to ask if they did not understand some words. Pronunciation instructions, however, were not given. The participants were then asked to read the text aloud as if they were telling the story to someone. If they stumbled, they could start again from the beginning of a sentence.The narrative text consisted of 16 sentences and the full recordings were approximately 1.5 min long. A subset of four utterances was selected for this study using the following principle: the target utterances differ from each other with respect to utterance and word length, vocabulary, and structure. The same four utterances were extracted from the seven native speakers and 56 L2 speakers, resulting in 28 L1 speech samples and 224 L2 samples. The utterances were extracted as grammatical sentences and are listed in N = 7), Slovak (N = 7), Hungarian (N = 13), and Polish (N = 13). Since our assessors were non-native speakers of English, they were asked to provide a self-evaluation of their English skills based on the CEFR descriptors  majoring either in English or Phonetics. The assessors’ L1s were Czech , silent pause–time ratio (SP-RATIO), silent pause frequency (SP-FREQ), filled pause–time ratio (FP-RATIO), filled pause frequency (FP-FREQ), correction/repetition–time ratio (CR-RATIO), and correction/repetition frequency (CR-FREQ), following the study by The prominence estimates for individual syllables were obtained using a continuous wavelet analysis technique originally developed for word prominence detection and described by CWT is a technique that decomposes a signal to a range of frequency components using a convolution of the signal with a scaled wavelet function. The wavelet function is scaled (stretched in time and amplitude) to obtain the components of appropriate frequencies. Applying the CWT decomposition to prosodic signals, as used here, yields the components roughly corresponding to prosodic events at various time scales, such as syllable, word, or phrase levels of prosodic analysis.For the utterance-sized samples used in study, annotated at a syllable level (yielding syllable durations), F0 contours were extracted using sample-dependent settings to avoid measurement errors arising from speaker- and sample-based F0 characteristics. Syllables with identical labels were numbered in order to separate them in the correlation analysis phase. Energy envelopes were acquired by band-pass filtering the speech signals between 400 and 5000 Hz and then extracting a smoothed Hilbert envelope.The extracted F0 and energy envelope signals were sampled at 200 Hz and pre-processed using the methods described in detail by en), and duration (dur): with each signal separately, all three pairs of signals, and the combination of all three signals.In order to evaluate which signal attributes correspond best to assessments of prosodic proficiency, we compared the CWT-based prominence estimates obtained from seven combinations of fundamental frequency (F0), energy envelope  numeric prominence value for every syllable in each analyzed utterance. Several measures were tested in this work in order to compare realizations of two utterances of the same sentence.z-scored or not) between the prominence vectors can be used as a measure of similarity.Two utterances can be compared by calculating a Pearson correlation coefficient using paired syllable-level prominence values. Alternatively, RMS distance . Similar to As in our previous work , using tAll statistical analyses were computed with the R program . The effAIC) in order to find out the relevant acoustic properties affecting prosodic proficiency assessment.We fitted the POLRs with grade (proficiency levels A1–C2 treated as an ordered factor) as a dependent variable and temporal measures or prominence distance measures as independent variables. For temporal measures, a model combining all measures as well as separate models for each measure was fitted. For prominence distance measures, POLRs were fitted separately for each feature combination used for estimating syllable prominence. In order to take into account the possible differences arising from the speakers’ L1s, the statistical models were centered for each speaker’s L1. We compared the models based on the Akaike information criterion .Collinearity amongst predictors is to be avoided with the proportional logistic regression model. Given the strong relationships among the temporal fluency measures considered here—for example, the frequency and ratio measures for the same type of pauses—we first evaluate the Pearson correlations among the measures. As seen in the correlation table , ARTRATEratio measures (continuous measures slightly less correlated with ARTRATE), but using the corresponding freq measures does not change the results qualitatively.Also, as expected, the correlations between the measures for the same temporal fluency phenomenon are quite high: 0.72 for the silent pause pairs, 0.83 for filled pauses, and 0.67 for correction/repetition. In order to mitigate potential multicollinearity effects and confounding effects mentioned in the introduction, we opted to avoid combining these highly correlated measures in single models. Therefore, here we report the results only involving the ratio plus their interactions with the speaker’s L1 were used as independent variables. To quantify the effect sizes for individual L1s, the fitted models were re-centered for each language separately. Furthermore, the interactions between any given individual measure and speakers’ L1s in the re-centered models were used to compare the effect sizes of the measure on the grade for different languages. In order to estimate the significance levels, p-values were further calculated from t-values with effective degrees of freedom used by the model (DF reported in model-specific summary tables). We chose to use significance levels of p = 0.01–0.05* and p < 0.01**.The relation between the temporal fluency measures and prosodic proficiency assessments was studied by fitting POLRs with grade treated as an ordered categorical dependent variable. The temporal measures ARTRATE, SP-RATIO, FP-RATIO, and CR-AIC value for the fit is 14,865. Given the AIC of the corresponding null model, 16,852, the fit explains around 11.8% of variance in the data.t-values from all independent variables, suggesting that this measure provides the greatest explanatory value in terms of grading. The differences among the reported effect sizes for the different L1 groups are significant, with the exception of the Slovak–Hungarian pair  between the L1 groups. The significantly positive effect of ARTRATE for all L1 groups means that the greater the ARTRATE (the faster the articulation), the better the grade. With the exception of the Polish L1 group, the ARTRATE yields the greatest absolute t-value For FP-RATIO, the fit demonstrates the expected negative relationship between this measure and the grades: the lower the ratio (the fewer filled pauses) the better grade. The effects for FP-RATIO are all significantly negative, except for Slovak for which the effect size is not significantly different from 0 . Similarly, the fit yields a significantly positive effect for CR-RATIO for the Czechs and Slovaks. Apart from Czech–Hungarian for both SP-RATIO and CR-RATIO  but relatively equally distributed among all L1 groups, while silent pauses are more common in the Slovak L1 group (mean SP-RATIO = 0.17) than in other groups .AIC values reveal a considerably better fit for ARTRATE (corresponding to 10.5% variance explained) compared to the remaining measures (between 6.5% and 6.9%).t-value for the effect sizes for all L1 groups including Polish, suggesting the greatest explanatory power for this measure in terms of grading.Also, when fitted separately, ARTRATE provides the highest In order to investigate the effect of syllable-level prominence production on prosodic proficiency assessments, we fitted POLRs separately for each feature combination used for CWT-based prominence estimates. The correlation between the CWT-based prominence estimates for L2 speakers with the best native match with interaction with the speaker L1 were used as independent variables; as before, the assessment grade is the dependent variable.t-values less than 2).dur, the effect sizes are all significantly different among the L1 groups except for the Polish–Hungarian pair (Comparing effect sizes for different fits (using the interaction with L1 as above) reveals an interesting pattern. For F0-based estimates, the effect sizes are not significantly different from each other, except for the Czech–Slovak pair , these fits explain between 4.19% (en) and 5.60% of variance.The This observation gives rise to the question of whether the prominence-based measures add any explanatory power in terms of assessment over the more traditional temporal measures.In order to address this question, we fitted POLRs combining the temporal fluency measures and prominence-based measures (one feature combination per model) as independent variables (with interactions with the L1 group) and used log-likelihood comparisons to compare them with the models using the temporal fluency measures only. All models with additional prominence-based measures provided significantly better fits regardless of the feature combination used . However, statistical models with temporal measures augmented with prominence-based measures explained the assessment results significantly better than the models with only the temporal measures. This indicates that syllable-level prominence realizations bring complementary information to the evaluation of L2 prosody (RQ3).Despite the variation in the research on temporal fluency in L2, most studies have found speed measures such as speech or articulation rate to be amongst the best predictors of fluency or prosodic proficiency . Our resratio = 0.05 for the Czech, 0.03 for the Slovak and Polish, and 0.02 for the Hungarian L1 groups), the predictive power of these measures should be examined critically. Our measures also remain insensitive to differences within disfluency types, such as the placement or length of an individual pause. These aspects, which could be important in the perception of fluency, should be investigated further with larger data and longer speech samples: in this study, the size of the speech data allowed the investigation of only the overall occurrence of disfluencies.The significance of individual temporal measures also varied among L1 groups when modeled separately. This was expected and can, on one hand, be partly attributed to the varying use of silent pauses (which were more common in the Slovak L1 group than in other L1 groups), and on the other hand to the rare occurrence of other disfluencies in the analyzed speech samples. When filled pauses, corrections, and repetitions do occur in speech, they might have a significant effect on prosodic proficiency assessments. However, since the ratio values remained very low  and researchers have questioned the role of duration in signaling prominence in Hungarian . The Hungarian speakers have consistently high effect sizes for all feature combinations involving energy, while duration alone yielded the lowest (yet significant) ungarian , we expeungarian . Hungariungarian . Since pFor the Polish speakers, the best predictive feature was F0, which has previously been found to be the most relevant cue in marking prominence in Polish . It is pFor the feature combinations F0-EN and F0-EN-DUR, the effect sizes were relatively similar among the Czech, Slovak, and Hungarian L1 groups. This may stem from the prosodic similarities among these languages, indicating that the CWT method could reveal interesting information about the similarities and differences among languages realized at the syllable level. It is also encouraging that the most closely related languages here—Czech and Slovak—behave in a relatively similar manner in terms of the effects of the CWT-based measures on proficiency assessments. The fact that the Polish L1 group stands out as different from the other L1 groups may stem from language-specific characteristics our analyses were unable to reveal, or from variation within the Polish L1 group.It should be noted that the native English speakers, used as a reference group in this study, consisted of four British English speakers and two American English speakers. We acknowledge that the number of speakers should be larger in order to give reliable representations of prominence realizations in the two varieties. However, by comparing each L2 utterance to all native English productions of the same utterance and choosing the native rendition with the highest correlation to the L2 production, we avoid possible bias that could emerge from mean or median prominence values of all native speakers.In our data, the higher proficiency levels (C1–C2) were rare in all L1 groups, which influenced statistical analyses for the higher grades. In general, the selected methods were able to distinguish less proficient (A-level) and advanced (C-level) speakers. However, distinguishing between neighboring levels, especially at the higher end of the scale, proved more challenging. This was also the case in our previous studies using the same CEFR scale , 2020. WThe consistency among assessors was very high in our study , despite the fact that we used non-professional and non-native raters. Various factors may have led to this high relative agreement: read speech is easier to assess, since the raters do not have to pay attention to grammar and vocabulary. Our raters were also trained identically and provided with specific instructions and scale for assessments, which have previously been shown to increase inter-rater reliability . The choThe results concerning the predictive power of CWT-based prominence estimates in this study differ from our previous research, where syllable prominence served as a more reliable predictor of prosodic proficiency . PossiblThe contribution of the local prominence-based measurements was relatively small compared to the more traditional temporal features. Nevertheless, our findings (alongside the earlier ones by This study compared traditionally used temporal measures and a relatively new method based on syllable prominence estimates as predictors of prosodic proficiency in non-native speakers of English with respect to their L1 backgrounds. Our results show that temporal measures, articulation rate in particular, serve as good predictors of prosodic proficiency of L2, while local prominence-based measures contribute to the quality of proficiency prediction. The predictive power of the measures varies with regards to speaker’s L1, especially for the syllable-level prominence. This indicates that L2 learners use different acoustic cues in prominence production depending on their L1. This issue remains little addressed in the existing research literature, as stress remains underrepresented in many L2 assessment systems and criteria. The present study reports on a preliminary attempt to untangle the acoustic complexity of L1 transfer to L2 stress production. We conclude that the effect of speaker’s L1 on the production of temporal features as well as syllable prominence in L2 should be taken into account when studying L2 prosody and developing teaching and assessment methods.


The task of transitioning from one interlocutor to another in conversation – taking turns – is a complex social process, but typically transpires rapidly and without incident in conversations between adults. Cross-linguistic similarities in turn timing and turn structure have led researchers to suggest that it is a core antecedent to human language and a primary driver of an innate “interaction engine.” This review focuses on studies that have tested the extent of turn timing and turn structure patterns in two areas: across language modalities and in early language development. Taken together, these two lines of research offer predictions about the development of turn-taking for children who are deaf or hard of hearing (DHH) acquiring sign languages. We introduce considerations unique to signed language development – namely the heterogenous ecologies in which signed language acquisition occurs, suggesting that more work is needed to account for the diverse circumstances of language acquisition for DHH children. We discuss differences between early sign language acquisition at home compared to later sign language acquisition at school in classroom settings, particularly in countries with national sign languages. We also compare acquisition in these settings to communities without a national sign language where DHH children acquire local sign languages. In particular, we encourage more documentation of naturalistic conversations between DHH children who sign and their caregivers, teachers, and peers. Further, we suggest that future studies should consider: visual/manual cues to turn-taking and whether they are the same or different for child or adult learners; the protracted time-course of turn-taking development in childhood, in spite of the presence of turn-taking abilities early in development; and the unique demands of language development in multi-party conversations that happen in settings like classrooms for older children versus language development at home in dyadic interactions. The task of transitioning from one interlocutor to another in conversation – taking turns – is a complex social process. Interlocutors who do not have the floor must process and comprehend ongoing turns, accurately anticipate when the person occupying the floor will provide an opportunity or solicit an opening for a turn shift, and, simultaneously, plan their own contribution . FollowiIn spite of the social and cognitive demands, turn-taking in adult conversations often proceeds smoothly and with considerable efficiency . And whe1 and hard of hearing (DHH) children acquiring signed languages. Prior work offers suggestions about the implications of language modality and development for turn-taking, but we also introduce considerations unique to signed language development – namely the heterogenous ecologies in which signed language acquisition occurs for DHH children.In this article, we consider evidence that this ‘‘universal’’ human skill extends across linguistic modalities, from oral/aural spoken languages to visual/manual signed languages, as well as evidence for the presence of turn-taking abilities early in infancy for hearing children acquiring spoken languages. Based on the literature on turn-taking across modalities and in development, we discuss predictions for the development of turn-taking for deaf2 for this article we will use the term local sign languages, often from smaller communities of signers with a shorter history of use, that are used primarily in the home or informal settings, in contrast with national sign languages, often used by larger, geographically dispersed communities of signers with a longer history of use both at home and in institutional settings like schools. We review the acquisition of turn-taking for DHH children in three settings – two settings from communities with a national sign language and one setting from communities where there is no national sign language in use. In communities with a national sign language, we discuss: family socialization of national sign languages at home and classroom socialization of national sign languages at school. In communities without a national sign language, we discuss family socialization of local sign languages at home. We suggest that there are unique challenges for each of these groups of DHH children, based on their differential access to the language in their environment with a particular focus on three factors that could significantly impact the trajectory of turn-taking development in DHH children learning a sign language. These factors include: (1) language modality—acquiring a visual/manual language, (2) ontogeny—development as a child learner, and (3) socio-cultural factors—characteristics of the acquisition ecology. We suggest that more work is needed to account for the diverse circumstances of language acquisition for DHH children and to consider the role of both modality and unique socialization contexts for the learning of turn-taking in conversation. In particular, we encourage researchers to consider: visual/manual cues to turn-taking and whether they are the same or different for child or adult learners; the protracted time-course of turn-taking development in childhood, in spite of the presence of turn-taking abilities early in development; and the unique demands of language development in multi-party conversations that happen in settings like classrooms for older children versus language development at home in dyadic interactions.The communicative ecologies for language acquisition that DHH children encounter vary across numerous characteristics but we focus on variation in two aspects: setting/interlocutors and language type. In terms of the settings for sign language acquisition, we discuss the difference between language acquisition at home with family members versus language acquisition at school with teachers and peers. In terms of language type, we discuss sign languages that vary along the following dimensions: the age of the language, the size of the community of users, the existence and availability of deaf education, access to medical technologies like hearing aids and cochlear implants, as well as prevailing ideologies about ‘‘best practices’’ for language development of DHH children. Although a variety of terms have been proposed to categorize sign languages,We begin with an overview of studies of turn-taking structures in signed language conversations between adults (see section “Documenting Turn-Taking Structures in Sign Languages”) then discuss studies that have explored modality effects on turn-taking timing and cues by comparing spoken and signed languages directly using either experimental or naturalistic adult conversational data . We then turn to studies of turn-taking in acquisition, providing a brief overview of work on turn-taking development in spoken language acquisition (section “Acquiring Turn-Taking Structures: Spoken Language Development”). In the final section we discuss sign language acquisition in the three social ecologies introduced above: (1) acquisition of a national sign language at home; (2) acquisition of a national sign language at school; and (3) acquisition of a local sign language at home. While there have been few studies dedicated to turn-taking in sign language acquisition, we review studies of interactional skills necessary for turn-taking like attention-getting and we discuss areas where future work could provide important insights for turn-taking development in the visual-manual modality.While many researchers of social behavior  have expressed intuitions that turn-taking patterns vary widely across cultures and languages, the broader paradigm of alternating turns between two or more interlocutors in many tasks, conversation or otherwise, seems to be a human universal , 2019. TDue to the time-intensive nature of collecting and annotating sign language conversation data, studies often involve a limited number of participants and use fewer than five conversations as their dataset, many use a single dyadic or multiparty conversation see . These sIn a descriptive study based on data from two conversations in American Sign Language (ASL), 3 She describes three possible rest positions for signers’ hands, including full-rest, half-rest, and quarter-rest Gaze, this suggests that they are ready for the producer to initiate or continue a turn. If the producer, however, makes eye contact with the addressee (+)Gaze, it often means that they are about to yield their turn. For child signers, this means they must acquire a complex set of signals that are contingent on their current status in an interaction. If a child signer is an addressee, making eye contact with their interlocutor (+)Gaze, will indicate something different than if they were currently the active signer.Many of the cues from Baker serve different functions depending on who produces them – Later studies have contested some of the claims in Baker. In their study of British Sign Language (BSL) conversations, for example, Coates and Sutton-Spence suggest that prior work on conversation structure, particularly turns, focused too much on conversations between dyads and conversations in formal settings like classrooms (p. 526). This led sign language researchers e.g.,  to asserturn construction units (TCUs) or if they were more common at turn relevance places (TRPs) and possible points of completion. In the DSGS conversation that Girard-Groeber analyzed, signers overlapped most frequently at TRPs and possible points of completion .In a study focused on the sequential context of turn overlaps in Swiss German Sign Language (DSGS), Girard-Groeber found substantial overlap of signed turns, even though only turns that overlapped the stroke phase of signs were included in the analysis. If a signer raised their hands to prepare to sign as another signer occupied the floor, this was excluded from the analysis because it was considered the preparatory phase of the sign. This finding contradicts some earlier claims about the significance of the current signer terminating a turn by returning their hands to a full “rest position.” Studies of naturalistic signed language conversations between adults generally suggest that there are specific signals associated with turn transitions as well as strategies for resolving overlapping turns when they occur, and while there is some evidence that turn overlaps happen frequently in signed conversations, it seems that these overlaps happen in similar places in conversational turns to spoken languages. We now turn to corpus and experimental studies that have compared spoken and signed language data directly to explore modality effects for two aspects of turn-taking: turn timing and cues to turn changes.one-at-a-time principle such that language users use strategies to minimize gaps and overlaps between turns.The study of turn-timing affords researchers a way to quantify and compare across disparate languages and social settings; but researchers face a challenge when determining what unit should be measured and compared. Early studies pointed out a basic principle of turn-taking—turn-length is rarely pre-determined in conversations. Regardless of the length of the preceding utterance, however, the transition between interlocutors happens across conversations and circumstances. In terms of timing, this transition could occur in one of three ways, (1) interlocutors could transition turns seamlessly, with no gap; (2) interlocutors could transition turns but there could be a gap with no speaking or signing; (3) interlocutors could overlap their turns, for a number of reasons, including (but not limited to) confusion about who will next occupy the floor, failure to end a turn when expected, or interruptions. one-at-a-time principle in a comparative study of ten languages that varied in their linguistic type  as well as contexts of use . Using video recordings of naturalistic conversations, they measured the “response offset” – the temporal relationship between turns – in polar question-response sequences.In their sample, response offsets were brief – for all languages in the dataset the mean was +208 ms – however there was a continuum of faster versus slower average response offsets across the sample (Japanese speakers had the fastest mean time for turn transitions at 7.29 ms while Danish speakers had the slowest at 468.88 ms). They found that four factors, including: answering, response type, non-verbal behaviors, and the presence of speaker gaze were significant predictors of response offset variation independent of the language spoken. Confirmation responses were faster than disconfirmation, responses with non-verbal behaviors  were faster than vocal-only responses, and responses were faster when the questioner gaze was directed to the addressee. Overall, Even though response offsets may be quantitatively similar across diverse communities of language users, humans appear to be remarkably attuned to the timing patterns in the language they use most often. Thus, within the overarching principle of “minimal gap, minimal overlap” , even smIn a subsequent study, Similar to previous studies of sign language turn-taking, researchers encountered challenges when measuring sign length and identifying sign boundaries. This challenge of what “counts” in measures of turn boundaries is not limited to signed languages. Although gestural cues and inbreaths have been considered potential cues to turn units in oral/aural languages, In The proportion of turns that overlap, based on “sign-naïve turn boundaries” in the NGT sample is 82.2%. This proportion is significantly higher than the proportion of overlapping turns in the cross-linguistic spoken languages sample from When de Vos et al. compared “sign-naïve” and “stroke-to-stroke” measures of turn timing directly, they found turn offsets based on “sign-naïve boundaries” had, on average, lengthy overlaps between turns . When turn offsets were based on “stroke-to-stroke” turn boundaries, there were, on average, short gaps between turns  see . This fiThe findings from the NGT sample of polar questions, both in terms of precise timing of turns and the resulting proportion of turns with significant overlaps or gaps  led the authors to conclude that “…it is therefore plausible that preparatory and retraction movements in signed conversation are best seen as parallel to the pre-beginnings and post-completion elements of spoken turns cf. , and thaQuantitative studies of turn-taking in national sign languages highlight the challenges of directly comparing spoken and signed languages, particularly when using precise measures for timing. Analyzed one way, the NGT sample suggests that overlapping turns in sign language conversations are more frequent and last longer than spoken language overlaps. But analyzed differently, NGT looks very similar to spoken languages, both in its exact timing and in the proportion of turn changes with overlaps and gaps. For DHH children acquiring a sign language, the results are somewhat inconclusive about the relationship between language modality and turn-timing. If children are attentive to the “stroke-to-stroke” cues that de Vos et al., coded, then they will be acquiring a system with similar timing patterns to spoken languages. If, however, they use cues like the preparatory movements of signers’ hands and arms or gaze, then it could be argued that they are acquiring a system with considerably more overlapping of turns than spoken language exchanges.Studies of turn timing have explicit criteria for isolating the unit of analysis: the person currently holding the floor finishes a turn and shifts to a different signer or speaker, but it has been harder for researchers to isolate and measure the cues that language users are producing and perceiving to anticipate turn beginnings and ends. When there is an exchange of turns, it is possible to measure the offset – gap or overlap – between language users. This consistency in the unit of analysis enabled researchers to compare across languages directly, both in a large cross-linguistic sample, and across language modalities between signed and spoken languages.Early work by In studies assessing the role of different kinds of cues for conversational turns, researchers often manipulate language data to control the amount of prosodic and lexical information participants can access. For example, by flattening the intonational contour of a recorded spoken language conversation. Participants are then asked to press a button when they think the current speaker has finished their turn . In theiDue to the difficulty of constructing stimuli, as well as recruiting participants, there have been very few studies of turn prediction in sign languages. Here we review 4 In particular, non-iconic lexical items that are not based on gestural patterns in the speech community, will not be available to them. Thus far we have focused on the relationship between turn-taking and language modality, but turn-taking patterns also vary across development or acquisition. We provide a brief overview of the work on acquisition of turn-taking in spoken languages before we introduce work on turn-taking and related communicative skills in signed language acquisition.For DHH children acquiring a sign language, this finding suggests that learners will have access to some cues for turns, even without early exposure to a sign language. They will not, however, be able to access all of the necessary cues without a language model and linguistic input.Beginning in the 1970s, a considerable body of work was developed focusing on the development of turn-taking in early childhood . Here weThe onset of turn-taking in infancy and childhood was initially debated, some early work debated the agency of infant children, who were observed to exchange vocally with caregivers well before they were able to produce language . ResearcRecalling that on average adult speakers have a 200 ms gap between turns, it is clear that children are slower than adults in their early vocal exchanges. And while turn timing may not be entirely driven by adult communication partners, children do appear to be affected by their interlocutor, based on the gap times reported by Based on a dataset of naturalistic conversations from 5 caregiver-child dyads between ages 1;8 and 3;5, Studies of spoken language interactions with young children thus suggest that children do have the capacity to intentionally engage others from a very young age, prior to their ability to produce or comprehend language, lending support for the universal “interaction engine” . HoweverIn a study of children’s ability to anticipate turn changes, All participants in the study were affected by turn type (question versus non-question); they made more anticipatory gaze switches following questions. Children  were also affected by the language used in the video. Younger children made more anticipatory gaze switches while watching clips from English conversations than non-English conversations, suggesting that children need access to lexicosyntactic information to predict the ends of turns, but as they develop they get better at making use of non-lexicosyntactic information. Contrary to prior findings that children rely primarily on lexical or syntactic information to predict turn endings, this study suggests that children (and adults) have alternative strategies to predict the ends of conversational turns when lexical or syntactic information is unavailable to them.In a follow-up study that more closely controlled the amount of prosodic and lexical information available to participants, Together with the results from studies of sign language turn prediction, studies of child speakers would suggest that DHH children should have some ability to anticipate turn changes in sign conversations from a young age. However, their ability to achieve adult-like efficiency in predicting turn changes will not occur until later in development. There is, further, a critical modality-based difference for DHH children acquiring a sign language versus hearing children acquiring a spoken language. While it is likely helpful for hearing children to be able to turn their head in time to see a speaker begin a turn in a spoken language conversation, DHH children will miss the linguistic signal completely if they do not direct their attention to the next signer in time to see the start of their turn. In other words, hearing children can hear a spoken language turn whether they are looking at the speaker or not, but a DHH children cannot see a signed turn if they are not looking at the signer. Whether gaze is a prerequisite of initiating a turn in adult signed conversations is somewhat contested, but for child signers this is a critical prerequisite for following and eventually entering into sign conversation. In order to follow signed conversation, child signers must recognize the cues and patterns of turns in signed turn exchanges. As noted in the introduction, researchers continue to debate whether the visual/manual modality of sign languages alters their turn-taking structure and whether this has implications for acquisition.5 where no one knows a sign language. They may be born in a community where there is not access to a national sign language or formal schooling for the deaf. In countries with universal hearing screenings at birth, children and their families are rapidly recruited into systems with support for medical interventions like hearing aids or cochlear implants and language intervention like speech therapy or sign language classes  spoken around them and gradually grow in their ability to comprehend and produce them. DHH children, however, are often in very different circumstances from hearing children. They are typically born into hearing families. classes . And whiAs discussed above, the majority of DHH children are born into hearing/speaking families . The smaIn their study comparing DHH and hearing infants from different contexts , Clearly the pace of linguistic turn-taking in the first year of life is slower for dyads in which child and mother are deaf than for dyads in which both are hearing. This difference in pace is to be expected because deaf persons must divide their visual attention between exploring objects in the environment and receiving communications. This effect is not observed in adult conversations, but is a pervasive characteristic of signed conversations with infants and toddlers who have not yet developed the ability to make smooth changes in focus of visual attention (p. 162).Meadow-Orlans et al. suggest that DHH caregivers adjust the pace and timing of their turns to accommodate the visual attention of their DHH child. As discussed above, learning a sign language places different demands on the child in terms of visual attention. In contrast to spoken language input, which the hearing child can access with or without visual attention to the speaker, the child learning a sign language must see signing in order to perceive it, and they must be attentive to engage in turn-taking. Visual attention is thus a necessary prerequisite to turn-taking in sign language, and we include studies of visual attention management in this review. Studies of mother–child dyads suggest that deaf signing mothers make significant adjustments to their signing to engage their child’s visual attention. There are contradictory reports in the literature, however, regarding the strategies that DHH signing mothers use with their DHH signing children.7In many studies, researchers report that deaf signing mothers seem to adopt less overt strategies for capturing and directing their DHH children’s attention; this is reflected in both the amount of time that DHH mothers spent waiting for their child’s attention, as well as their use of explicit attention-getting signals. In a study of four mother-child dyads,8 used few attention-getting devices with their signing children, noting that “In general, parents of two-year-old’s seemed willing to wait for their children’s attention and to allow the child to set the pace of the conversation” (p. 66). Holzrichter compared 2-year-old and 4-year-old signers, reporting that all children were most likely to be engaged in mutual gaze with their parents for most turns (72–77% of turns across the sample), with parents looking away during turns with 4-year-old’s more often than 2-year-old’s. Holzrichter suggests that withholding or averting their gaze could be a strategy that parents of older children are using to maintain the floor, noting that the 4-year-old’s were much more active contributors to conversations, introducing new topics and actively competing for the floor (p. 64).In a cross-linguistic comparative study of deaf children  in deaf signing families from Spain and the United States, The results from Holzrichter are compatible with findings from an earlier study by In general, these studies suggest that deaf signing parents may be less focused on directing or attracting their child’s attention, and more attentive to where the child is already looking and adjusting their own signing, when necessary, to place it within the child’s field of vision or to comment on the target of the child’s visual attention. For the acquisition of turn-taking and early turn-taking patterns between DHH signing adults and young DHH children, this indicates that turn-taking may be quite slow and characterized by sustained breaks in interaction while the adult waits on the child’s attention before initiating the next turn. Deaf signing mothers may seek to provide targeted input and, in particular, are very careful to make sure that they have the child’s attention before they sign, a finding reported across numerous studies of signing conversations with young deaf children. Reports of patient, watchful waiting from deaf signing caregivers contrast somewhat with studies that report on more explicit or overt efforts to get the attention of deaf signing children or to elicit signing from them. 9 enter this ecology at a much later stage of cognitive and social development, in addition to the differences between home and school social settings  directed the class’s attention to a section on the worksheet listing the materials needed for the experiment. She opened the discussion with her WH-question pattern, signing “now,” pointing to the appropriate section on her overhead, and asking what it said… Danny and a number of other students raised their hands. Before anyone was called on, however, Danny dropped his hand and began fingerspelling “materials” to himself. He looked down at the worksheet to confirm the spelling, and continued fingerspelling to himself as Connie pointed to another student, Larry, in the back of the room. As a result, Danny missed Connie’s allocation of the turn to Larry, and when he looked around the room, could not locate him in time to see the answer (pp. 16–17).The authors note that Danny loses track of the conversation, causing him to miss other students’ turns as well as the teachers’ instructions. Danny’s missing skills in discourse were particularly noteworthy to the authors because of his advanced age, but his difficulties closely resemble many patterns observed for younger DHH children in signing preschool classrooms who come from hearing/speaking families.There have been several studies of children who are acquiring a national sign language in classroom settings. As mentioned above, the majority of DHH students are not receiving consistent sign language input at home and thus depend on the language input that they are exposed to at school to acquire the national sign language. Many studies compare students who do receive sign language input at home  to students who are from hearing families . In the following sections, we discuss these studies, summarized in A diverse range of methodologies have been used to study classroom interactions, including longitudinal engagement with a single classroom , samplinWhile many DHH children are receiving their primary language input in the classroom, the classroom ecology is remarkably distinct from the home context described for DHH children learning a national sign language at home . One sigConversations in classrooms diverge significantly from other social settings. In a pattern first identified by In contrast to the studies of DHH signing parents discussed in section “Deaf or Hard of Hearing Children Acquiring a National Sign Language at Home” that report that caregivers often used a strategy of waiting for their child’s attention, many studies of classroom sign language socialization document explicit attention management strategies used by signing teachers. These strategies are numerous; in a study of a British nursery school, In a study of a signing preschool classroom, In a similar study of teacher attention strategies in a signing preschool classroom in Toronto, In addition to manual strategies for managing attention, some studies have documented non-manual techniques that teachers use to manage student attention. In a study of two signing classrooms, Whether teachers are using manual or non-manual cues like eye gaze, the visual and conversational demands on students in the signing classroom setting are high. Studies from Beyond the individual strategies and cues that teachers employ, other studies have highlighted the significant role of deaf signing teachers, to provide more naturalistic interactions for deaf signing students than might normally happen in a classroom setting. In their comparative study of deaf signing preschools in the United States, France, and Japan, While many studies of adult-child conversations (both sign and speech) note that adults often scaffold interactions for the child participant, sometimes peer conversations between children do not proceed as smoothly. As noted in section “Acquiring turn-taking structures: Spoken language development”, for example, turn gaps between child peers at ages 2–4 were significantly longer than adult turn gaps . In a stIn the spoken languages show significant delays in pragmatic skills  can lead to native-like results, even for DHH children who are in hearing families [see Deaf or hard of hearing children born into hearing families in countries with a national sign language enter communities with specific beliefs about appropriate and necessary interventions. In other countries the national sign language may not be as widely used, medical interventions may be less common, affordable, or accessible, and schools for the deaf may be geographically or financially inaccessible to DHH children. Without early hearing screenings, many families may not know that their child is deaf until much later, sometimes 6 or 7 years old. In this context, DHH children and adults often develop and use local sign languages to communicate with hearing relatives and friends. As mentioned in the introduction, there is immense variation in these systems, in terms of how many signers they have, the geographic spread of their use, and hearing people’s attitudes toward deaf people and signing. In this section, we consider implications for development of turn taking in sign language conversations for children in these settings. While extensive work has documented the lexical, morphological, and syntactic properties of many of these languages, fewer studies have focused on pragmatic practices like turn taking. We discuss studies that have described turn-taking in local sign languages used in Central and South America, as well as areas for future study.In a comparative study of child sign socialization from three communities, including “Z” as well as signers from the village of San Juan Quiahije, in Oaxaca, Mexico, and the town of Nebaj, in Guatemala, While this body of work on emerging sign languages is still developing, we hope that going forward these researchers will go beyond single signer informants and collect video-recordings of caregiver-child dyads and multi-party conversations as well to explore conversational and pragmatic practices in signed languages. In many of these communities, multi-party interactions are more common for children to experience because several families can live together within a compound, or children are cared for by extended family networks or older siblings. It will be especially interesting to note the timing of turns and whether overlaps are more likely to exist in young sign languages.In this article we have reviewed studies that explore the relationship between language modality and turn-taking, the trajectory of turn-taking skills in infancy and childhood, as well as the development of turn-taking in diverse social ecologies for sign language acquisition. This work sets up several puzzles, as well as areas for future investigation. In terms of the relationship between language modality and turn-taking, by some measures, turn-timing in sign languages closely patterns with that of spoken languages for particular turn types (polar question and answer sequences). Further, conversations in sign and speech seem to be generally guided by the same underlying principle of minimizing overlaps as well as gaps between turns, lending support for a universal “interaction engine” . HoweverFor the acquisition of turn-taking in childhood, unlike other domains of language use, children seem to have the ability and desire to engage in turn-taking activities and behaviors from a very young age. As they develop, there is some evidence that increasing linguistic and social skills may slow down their prelinguistic alternations with caregivers. Thus, even though some of this ability appears quite early, its time course is actually quite protracted and interacts with other developmental milestones .The early availability of turn-taking behaviors has implications for DHH children acquiring a sign language at older stages of development. Particularly in combination with evidence that some pragmatic cues for turn-taking in sign languages appear to be available to hearing adults with co-speech gesture experience but no sign language experience . These tIf the classroom environment is the primary site of sign language socialization for DHH children from hearing families who do not sign, one strategy might be for teachers to emulate DHH signing parents. Based on the literature documenting deaf signing caregivers’ practices, this entails creating an immersive signing environment in which the adult signer waits for the novice signer’s visual attention or adapts their signing to be within the novice signer’s visual field. In the classroom, this might involve waiting for DHH students to notice or develop their visual monitoring skills without explicit prompts or scaffolding. This is not, however, what studies have found is the predominant pattern in signing classrooms. Teachers appear to often use very explicit socializing strategies, though this may vary significantly based on the activity. In a recent study of shared story-time in kindergarten and first grade classrooms, As discussed across several sections, the social demands and affordances of these three diverse settings for acquisition have significant implications for the development of turn-taking skills. While national sign language acquisition that occurs in deaf families at home may be characterized by less input that is very targeted to the individual child, this may not be feasible in a classroom setting. Further, the DHH child is immersed in sign language and visual-manual turn-taking activities from early in development and in interactions that are primarily about socialization. Before the DHH child is fully mobile and prior to their acquisition of linguistic skills, they can be the recipient of targeted input that is adapted to their attentional abilities. National sign language acquisition in the signing classroom happens for DHH children who are already mobile and who are already part of families that are using speech and auditory cues for turn-taking. Thus, they are getting less sign language input in a context in which there is significantly more competition – both for their visual attention and for the conversational signing floor – as they are typically engaged in multiparty interactions with both their peers and their teacher. We still lack significant information about how turn-taking transpires in multiparty adult signing conversations, but in classrooms, many teachers seem to focus on managing turns so that students do not overlap with one another, and on supporting DHH students who are struggling to figure out where to direct their attention . The acqDeaf or hard of hearing children acquire sign languages in highly variable contexts, making it difficult to isolate the relative contributions of language modality, linguistic and cognitive development, and social setting, to any language practice. By gathering more thorough data from naturalistic interactions across these ecologies, we will be better able to piece together the emergence of turn-taking skills in sign language development, and interrogate the relationship between modality and turn-taking in conversation.Both authors listed have made a substantial, direct, and intellectual contribution to the work, and approved it for publication.