1,720,998 research outputs found

    Initial evaluation of an auditory-model-aided selection procedure for non-individual HRTFs

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    Binaural spatial audio reproduction systems use measured or simulated head-related transfer functions (HRTFs), which encode the effects of the outer ear and body on the incoming sound to recreate a realistic spatial auditory field around the listener. The sound localisation cues embedded in the HRTF are highly personal. Establishing perceptual similarity between different HRTFs in a reliable manner is challenging due to a combination of acoustic and non-acoustic aspects affecting our spatial auditory perception. To account for these factors, we propose an automated procedure to select the ‘best’ non-individual HRTF dataset from a pool of measured ones. For a group of human participants with their own acoustically measured HRTFs, a multi-feature Bayesian auditory sound localisation model is used to predict individual localisation performance with the other HRTFs from within the group. Then, the model selection of the ‘best’ and the ‘worst’ non-individual HRTFs is evaluated via an actual localisation test and a subjective audio quality assessment in comparison with individual HRTFs. A successful model-aided objective selection of the ‘best’ non-individual HRTF may provide relevant insights for effective and handy binaural spatial audio solutions in virtual/augmented reality (VR/AR) applications

    Robust impaired speech segmentation using neural network mixture model

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    This paper presents a signal processing technique for segmenting short speech utterances into unvoiced and voiced sections and identifying points where the spectrum becomes steady. The segmentation process is part of a system for deriving musculoskeletal articulation data from disordered utterances, in order to provide training feedback for people with speech articulation problem. The approach implement a novel and innovative segmentation scheme using artificial neural network mixture model (ANNMM) for identification and capturing of the various sections of the disordered (impaired) speech signals. This paper also identify some salient features that distinguish normal speech from impaired speech of the same utterances. This research aim at developing artificial speech therapist capable of providing reliable text and audiovisual feed back progress report to the patient

    Differential evolution schemes for speech segmentation: a comparative study

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    This paper presents a signal processing technique for segmenting short speech utterances into unvoiced and voiced sections and identifying points where the spectrum becomes steady. The segmentation process is part of a system for deriving musculoskeletal articulation data from disordered utterances, in order to provide training feedback. The functioning of the signal processing technique has been optimized by selecting the parameters of the model. The optimization has been carried out by testing and comparing multiple Differential Evolution implementations, including a standard one, a memetic one, and a controlled randomized one. Numerical results have also been compared with a famous and efficient swarm intelligence algorithm. For the given problem, Differential Evolution schemes appear to display a very good performance as they can quickly reach a high quality solution. The binomial crossover appears, for the given problem, beneficial with respect to the exponential one. The controlled randomization appears to be the best choice in this case. The overall optimized system proved to segment well the speech utterances and efficiently detect its uninteresting part

    The Audio-Corsi: an acoustic virtual reality-based technological solution for evaluating audio-spatial memory abilities

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    Spatial memory is a cognitive skill that allows the recall of information about the space, its layout, and items’ locations. We present a novel application built around 3D spatial audio technology to evaluate audio-spatial memory abilities. The sound sources have been spatially distributed employing the 3D Tune-In Toolkit, a virtual acoustic simulator. The participants are presented with sequences of sounds of increasing length emitted from virtual auditory sources around their heads. To identify stimuli positions and register the test responses, we designed a custom-made interface with buttons arranged according to sound locations. We took inspiration from the Corsi-Block test for the experimental procedure, a validated clinical approach for assessing visuo-spatial memory abilities. In two different experimental sessions, the participants were tested with the classical Corsi-Block and, blindfolded, with the proposed task, named Audio-Corsi for brevity. Our results show comparable performance across the two tests in terms of the estimated memory parameter precision. Furthermore, in the Audio-Corsi we observe a lower span compared to the Corsi-Block test. We discuss these results in the context of the theoretical relationship between the auditory and visual sensory modalities and potential applications of this system in multiple scientific and clinical contexts

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

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