Publications

Abstract

The classification of texts and pieces of texts uses the occurrence of, combinations of, words as an important indicator. Not every word or each combination of words gives a clear indication of the classification of a piece of text. Research has been done on methods that select some words or combinations of words that are more indicative of the type of a piece of text. These words or combinations of words are selected from the words and word-groups as they occur in the texts. These more indicative words or combinations of words we call ¿cue-phrases¿. The goal of these methods is to select the most indicative cue-phrases first. The collection of selected words and/or combinations thereof can then be used for training the classification system. To test these selection methods, a number of experiments has been done on a corpus containing cookbook recipes and on a corpus of four-participant meetings. To perform these experiments, a computer program was written. On the recipe corpus we looked at classifying the sentences into different types. Some examples of these types include ¿requirement¿ and ¿instruction¿. On the four-person meeting corpus we tried to learn, using only lexical features, whether a sentence is addressed to an individual or a group. The experiments on the recipe corpus produced good results that showed that, a number of, the used cue-phrase selection methods are suitable for feature selection. The experiments on the four-person meeting corpus where less successful in terms of performance off the classification task. We did see comparable patterns in selection methods, and considering the results of Jovanovic we can conclude that different features are needed for this particular classification task. One of the original goals was to look at ¿addressee¿ in discussions. Are sentences more often addressed to individuals inside discussions compared to outside discussions? However, in order to be able to accomplish this, we must first identify the segments of the text that are discussions. It proved hard to come to a reliable specification of discussions, and our initial definition wasn¿t sufficient.

Abstract

This paper describes ongoing research aiming at the description of variation in speech as represented by asynchronous articulatory features. We will first illustrate how distances in the articulatory feature space can be used for event detection along speech trajectories in this space. The temporal structure imposed by the cosine distance in articulatory feature space coincides to a large extent with the manual segmentation on phone level. The analysis also indicates that the articulatory feature representation provides better such alignments than the MFCC representation does. Secondly, we will present first results that indicate that articulatory features can be used to probe for acoustic differences in the onsets of Dutch singulars and plurals.

Abstract

This paper builds on previous work that aims at unraveling the structure of the speech signal by means of using probabilistic representations. The context of this work is a multi-pass speech recognition system in which a phone lattice is created and used as a basis for a lexical search in which symbolic mismatches are allowed at certain costs. The focus is on the optimization of the costs of phone insertions, deletions and substitutions that are used in the lexical decoding pass. Two optimization approaches are presented, one related to a multi-pass computational model for human speech recognition, the other based on a decoding in which Bayes’ risks are minimized. In the final section, the advantages of these optimization methods are discussed and compared.

Abstract

The Papuan languages of the central Solomon Islands are a negatively defined areal grouping: They are those four or possibly five languages in the central Solomon Islands that do not belong to the Austronesian family. Bilua (Vella Lavella), Touo (Rendova), Lavukaleve (Russell Islands), Savosavo (Savo Island) and possibly Kazukuru (New Georgia) have been identified as non-Austronesian since the early 20th century. However, their affiliations both to each other and to other languages still remain a mystery. Heterogeneous and until recently largely undescribed, they present an interesting departure from what is known both of Austronesian languages in the region and of the Papuan languages of the mainland of New Guinea.

Abstract

This book provides an overview of the grammatical structure of the language Yurakaré, an unclassified and previously undescribed language of central Bolivia. It consists of 8 chapters, each describing different aspects of the language. Chapter 1 is an introduction to the Yurakaré people and their language. Chapter 2 describes the phonology of the language, from the individual sounds to the stress system. In chapter 3 the morphology of Yurakaré is introduced, i.e. the parts of speech, and the different morphological processes. Chapter 4 is a description of the noun phrase and contains information about nouns, adjectives, postpositions and quantifiers. It also discusses the categories associated with the noun phrase in Yurakaré, such as number, possession, collectivity/distributivity, diminutive. In chapter 5, called 'Verbal agreement, voice and valency' there is a description of the argument structure of predicates, how arguments are expressed and how argument structure can be altered by means of voice and valency-changing operations such as applicatives, causative and middle voice. In chapter 6 there is an overview of verbal morphology, apart from the morphology associated with voice, valency and cross-reference discussed in chapter 5. There is also a description of adverbs in the language in this chapter. Chapter 7 discusses formal and functional properties of modal and aspectual enclitics. In chapter 8, finally, the structure of the clause (both simplex and complex) is discussed, including the switch-reference system and word order. The book ends with two text samples.

Abstract

Pitch, intonation, and speech rate were analyzed in a collection of everyday speech heard by one Dutch infant between the ages of six and nine months. Components of each of these variables were measured in the speech of three adult speakers (mother, father, baby-sitter) when they addressed the infant, and when they addressed another adult. The results are in line with previously reported findings which are usually based on laboratory or prearranged settings: infant-directed speech in a natural setting exhibits more pitch variation, a larger number of simple intonation contours, and slower speech rate than does adult-directed speech.

Abstract

Dutch distinguishes at least four sentence types: statements and questions, the latter type being subdivided into wh-questions (beginning with a question word), yes/no-questions (with inversion of subject and finite), and declarative questions (lexico-syntactically identical to statement). Acoustically, each of these (sub)types was found to have clearly distinct global F0-patterns, as well as a characteristic distribution of final rises [1,2]. The present paper explores the separate contribution of parameters of global downtrend and size of accent-lending pitch movements versus aspects of the terminal rise to the human identification of the four sentence (sub)types, at various positions in the time-course of the utterance. The results show that interrogativity in Dutch can be identified at an early point in the utterance. However, wh-questions are not distinct from statements.

Abstract

Recent studies using phoneme detection tasks have shown that spoken-language processing is neither facilitated nor interfered with by optional assimilation, but is inhibited by violation of obligatory assimilation. Interpretation of these results depends on an assessment of their generality, specifically, whether they also obtain when listeners are processing nonnative language. Two separate experiments are presented in which native listeners of German and native listeners of Dutch had to detect a target fricative in legal monosyllabic Dutch nonwords. All of the nonwords were correct realisations in standard Dutch. For German listeners, however, half of the nonwords contained phoneme strings which violate the German fricative assimilation rule. Whereas the Dutch listeners showed no significant effects, German listeners detected the target fricative faster when the German fricative assimilation was violated than when no violation occurred. The results might suggest that violation of assimilation rules does not have to make processing more difficult per se.

Abstract

Utilization of computer tools in linguistic research has gained importance with the maturation of media frameworks for the handling of digital audio and video. The increased use of these tools in gesture, sign language and multimodal interaction studies has led to stronger requirements on the flexibility, the efficiency and in particular the time accuracy of annotation tools. This paper describes the efforts made to make ELAN a tool that meets these requirements, with special attention to the developments in the area of time accuracy. In subsequent sections an overview will be given of other enhancements in the latest versions of ELAN, that make it a useful tool in multimodality research.

Abstract

A number of serious reasons will convince an increasing amount of researchers to store their relevant material in centers which we will call "language resource archives". They combine the duty of taking care of long-term preservation as well as the task to give access to their material to different user groups. Access here is meant in the sense that an active interaction with the data will be made possible to support the integration of new data, new versions or commentaries of all sort. Modern Language Resource Archives will have to adhere to a number of basic principles to fulfill all requirements and they will have to be involved in federations to create joint language resource domains making it even more simple for the researchers to access the data. This paper makes an attempt to formulate the essential pillars language resource archives have to adhere to.

Abstract

Although sign language-using communities exist in all areas of the world, few sign languages have been documented in detail. Sign languages occur in a variety of sociocultural contexts, ranging from sign languages used in closed village communities to officially recognized national sign languages. They may be grouped into language families on historical grounds or may participate in various language contact situations. Systematic cross-linguistic comparison reveals both significant structural similarities and important typological differences between sign languages. Focusing on information from non-Western countries, this article provides an overview of the sign languages of the world.