Machine Assisted Analysis of Vowel Length Contrasts in Wolof

Growing digital archives and improving algorithms for automatic analysis of text and speech create new research opportunities for fundamental research in phonetics. Such empirical approaches allow statistical evaluation of a much larger set of hypothesis about phonetic variation and its conditioning factors (among them geographical / dialectal variants). This paper illustrates this vision and proposes to challenge automatic methods for the analysis of a not easily observable phenomenon: vowel length contrast. We focus on Wolof, an under-resourced language from Sub-Saharan Africa. In particular, we propose multiple features to make a fine evaluation of the degree of length contrast under different factors such as: read vs semi spontaneous speech ; standard vs dialectal Wolof. Our measures made fully automatically on more than 20k vowel tokens show that our proposed features can highlight different degrees of contrast for each vowel considered. We notably show that contrast is weaker in semi-spontaneous speech and in a non standard semi-spontaneous dialect.Comment: Accepted to Interspeech 201

Comparing causal-noncausal alternation in three West-African families in contact: Atlantic, Mel and Mande

Submitted to Language Dynamics and Change, special issue on Valence orientation in contact: a cross-linguistic perspective. Proceedings of the Workshop on Valence orientation in contact at the 51st Annual Meeting of the Societas Linguistica Europaea (SLE) (August 29-September 1st 2018), Tallinn, Estonia,This paper investigates the coding of causal-noncausal alternation in three families of languages spoken in West Africa, studying divergence and convergence within and between these families along with various methodological problems related to this cross-linguistic comparison. Atlantic, Mande and Mel languages belong to the same Niger-Congo phylum but display quite different typological profiles and have long lasting historical contacts in Senegal and the surrounding areas. In order to evaluate the correlation between typological profile and valence orientation and to identify contact-induced changes, the same 18 verb-pair meanings (Nichols et al. 2004) have been retrieved from the RefLex lexical database for all the documented Atlantic languages, and for the Mande and Mel languages in contact with them. After overcoming a bias in the list of pairs (favoring causativization), the first results confirm the expected correlation between the favored strategies and the typological profiles, namely lability for Mande (isolating languages with a limited set of derivational suffixes and regularly labile verb) vs. derivational strategies for Atlantic and Mel languages (displaying a large inventory of verbal extensions). In addition, the equipollent strategy shows a surprisingly significant score in Atlantic and Mel, and the suppletive one in the three families. The first one is attributed to structural features of these languages, the second one is interpreted as an areal feature. A standard pattern of distribution of the five strategies for coding valence alternation (based on optimized samples of languages for overcoming data shortage) is then calculated for each family and used for measuring the deviation of individual languages from family pattern. Thanks to a fine-grained study taking into account the structural features of individual languages and the geographical contacts, these deviations are finally attributed to internal evolution of individual languages or of sub-groups of languages and, in a few cases, to contact induced changes. The most salient result is the remarkable heterogeneity observed inside Atlantic family for valence orientation, undoubtlessly reflecting the historical depth of the family

Speed perturbation and vowel duration modeling for ASR in Hausa and Wolof languages

International audienceAutomatic Speech Recognition (ASR) for (under-resourced) Sub-Saharan African languages faces several challenges: small amount of transcribed speech, written language normalization issues, few text resources available for language modeling, as well as specific features (tones, morphology, etc.) that need to be taken into account seriously to optimize ASR performance. This paper tries to address some of the above challenges through the development of ASR systems for two Sub-Saharan African languages: Hausa and Wolof. First, we investigate data augmentation technique (through speed perturbation) to overcome the lack of resources. Secondly, the main contribution is our attempt to model vowel length contrast existing in both languages. For reproducible experiments, the ASR systems developed for Hausa and Wolof are made available to the research community on github. To our knowledge, the Wolof ASR system presented in this paper is the first large vocabulary continuous speech recognition system ever developed for this language

LESSONS LEARNED AFTER DEVELOPMENT AND USE OF A DATA COLLECTION APP FOR LANGUAGE DOCUMENTATION (LIG-AIKUMA)

International audienceLig-Aikuma is a free Android app running on various mobile phones and tablets. It proposes a range of different speech collection modes (recording, respeaking, translation and elicitation) and offers the possibility to share recordings between users. More than 250 hours of speech in 6 different languages from sub-Saharan Africa (including 3 oral languages in the process of being documented) have already been collected with Lig-Aikuma. This paper presents the lessons learned after 3 years of development and use of Lig-Aikuma. While significant data collections were conducted, this has not been done without difficulties. Some mixed results lead us to stress the importance of design choices, data sharing architecture and user manual. We also discuss other potential uses of the app, discovered during its deployment: data collection for language revitalisation, data collection for speech technology development (ASR) and enrichment of existing corpora through the addition of spoken comments

Collecting Resources in Sub-Saharan African Languages for Automatic Speech Recognition: a Case Study of Wolof

International audienceThis article presents the data collected and ASR systems developped for 4 sub-saharan african languages (Swahili, Hausa, Amharic and Wolof). To illustrate our methodology, the focus is made on Wolof (a very under-resourced language) for which we designed the first ASR system ever built in this language. All data and scripts are available online on our github repository

Le paysage comme medium dans l’analyse des jeux d’acteurs territoriaux : expérience dans la vallée du Cher (France)

La continuité écologique des rivières est devenue une préoccupation au sein des institutions de gestion, confrontées à l'application des directives européennes. Cela peut se traduire par la destruction d'aménagements fluviaux, par exemple des barrages. Dans la vallée du Cher, affluent de la Loire, une étude a été réalisée dans une cadre d'un exercice pédagogique avec une promotion d'élèves-ingénieurs paysagistes de l'école du paysage de Blois (France). A partir d'une analyse paysagère destinée à renouveler les objectifs de planification de la rivière, elle a permis d'interroger particulièrement les représentations du problème par des acteurs locaux. Une méthode d'analyse du jeu d'acteurs combinée à une approche territoriale et paysagère permet de faire état du système complexe de représentations et de décision, et de dépasser les possibles conflits. Recently in France, the ecological continuity of rivers has become a preoccupation within the managing organisations that are confronted with the application of the European directive that implies, in some cases, the destruction of structures, among which are dams. In the Cher valley, a tributary of the Loire, a study has been carried out in the framework of an exercise with landscape architecture students (M1 National School of Higher Studies in Nature and Landscape Architecture, Blois, France). It called for a landscape analysis to renew the river stream planning. It implied questioning more specifically the involvement of local stakeholder organisations, notably in the context of territorial conflicts. We have developed an elaborate approach, especially regarding the analysis of the stakeholder system, which gives a new interpretation of the landscape by its actors

Speech Technologies for African Languages: Example of a Multilingual Calculator for Education

International audienceThis paper presents our achievements after 18 months of the ALFFA project dealing with African languages technologies. We focus on a multilingual calculator (Android app) that will be demonstrated during the Show and Tell session

The LINC complex contributes to heterochromatin organisation and transcriptional gene silencing in plants

​The LInker of Nucleoskeleton and Cytoskeleton (LINC) complex is an evolutionary well-conserved protein bridge connecting the cytoplasmic and nuclear compartments across the nuclear membrane. While recent data support its function in nuclear morphology and meiosis, its implication in chromatin organisation has not been studied in plants. Here 3D imaging methods have been used to investigate nuclear morphology and chromatin organisation in interphase nuclei of the model plant Arabidopsis thaliana, in which heterochromatin cluster in conspicuous chromatin domains called chromocentres. Chromocentres form a repressive chromatin environment contributing to transcriptional silencing of repeated sequences, a general mechanism needed for genome stability. Quantitative measurements of 3D position of chromocentres indicate their close proximity to the nuclear periphery but that their position varies with nuclear volume and can be altered in specific mutants affecting the LINC complex. Finally we propose that the plant LINC complex contributes to proper heterochromatin organisation and positioning at the nuclear periphery, since its alteration is associated with the release of transcriptional silencing as well as decompaction of heterochromatic sequences

Associated Motion and Deictic Directional in Atlantic languages

International audienc