329 research outputs found

    Treatise on Hearing: The Temporal Auditory Imaging Theory Inspired by Optics and Communication

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    A new theory of mammalian hearing is presented, which accounts for the auditory image in the midbrain (inferior colliculus) of objects in the acoustical environment of the listener. It is shown that the ear is a temporal imaging system that comprises three transformations of the envelope functions: cochlear group-delay dispersion, cochlear time lensing, and neural group-delay dispersion. These elements are analogous to the optical transformations in vision of diffraction between the object and the eye, spatial lensing by the lens, and second diffraction between the lens and the retina. Unlike the eye, it is established that the human auditory system is naturally defocused, so that coherent stimuli do not react to the defocus, whereas completely incoherent stimuli are impacted by it and may be blurred by design. It is argued that the auditory system can use this differential focusing to enhance or degrade the images of real-world acoustical objects that are partially coherent. The theory is founded on coherence and temporal imaging theories that were adopted from optics. In addition to the imaging transformations, the corresponding inverse-domain modulation transfer functions are derived and interpreted with consideration to the nonuniform neural sampling operation of the auditory nerve. These ideas are used to rigorously initiate the concepts of sharpness and blur in auditory imaging, auditory aberrations, and auditory depth of field. In parallel, ideas from communication theory are used to show that the organ of Corti functions as a multichannel phase-locked loop (PLL) that constitutes the point of entry for auditory phase locking and hence conserves the signal coherence. It provides an anchor for a dual coherent and noncoherent auditory detection in the auditory brain that culminates in auditory accommodation. Implications on hearing impairments are discussed as well.Comment: 603 pages, 131 figures, 13 tables, 1570 reference

    GENCODE reference annotation for the human and mouse genomes

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    The accurate identification and description of the genes in the human and mouse genomes is a fundamental requirement for high quality analysis of data informing both genome biology and clinical genomics. Over the last 15 years, the GENCODE consortium has been producing reference quality gene annotations to provide this foundational resource. The GENCODE consortium includes both experimental and computational biology groups who work together to improve and extend the GENCODE gene annotation. Specifically, we generate primary data, create bioinformatics tools and provide analysis to support the work of expert manual gene annotators and automated gene annotation pipelines. In addition, manual and computational annotation workflows use any and all publicly available data and analysis, along with the research literature to identify and characterise gene loci to the highest standard. GENCODE gene annotations are accessible via the Ensembl and UCSC Genome Browsers, the Ensembl FTP site, Ensembl Biomart, Ensembl Perl and REST APIs as well as https://www.gencodegenes.org.National Human Genome Research Institute of the National Institutes of Healt

    Complex acoustic environments: concepts, methods and auditory perception

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    Thesis by publication.Bibliography: pages 191-215.1. Introduction -- 2. The ambisonic recordings of typical environments (ARTE) database -- 3. Conversational speech levels and signal-to-noise ratios in realistic conditions -- 4. Complex acoustic environments: review, framework and subjective model -- 5. Exploring the ability of listeners to identify events in realistic environments -- 6. General discussion and conclusions -- Appendices.In everyday life, the ears constantly receive information from the environment that is carried by sound waves. Despite the uncontrolled nature of this information, normal hearing listeners can make sense of the unstructured sounds. In contrast, hearing has mostly been studied using acoustic stimuli that are rigidly controlled. The difference between understanding such artiļ¬cial stimuli and real-world hearing has produced the distinction of ā€™complex acoustic environmentsā€˜ (CAEs) ā€“ a catch-all term for everything that the laboratory-based stimuli are not. However, an exact deļ¬nition has been elusive, despite growing use in hearing research ā€“ especially in research focusing on hearing-impaired individuals, who struggle communicating in cocktail-party like scenarios. In this work, several aspects of CAEs were studied with the intention to understand where the complexity lies. The work consists of four main parts in manuscript form. The ļ¬rst paper presents the Ambisonic Recordings of Typical Environments (ARTE) database, which contains 3D recordings of everyday scenarios. These were the primary stimuli used in all subsequent parts of this work. In the second paper, the speech and noise levels of real conversations were measured at two distances between talkers. The third paper reviews the origins and uses of the CAE concept in literature and presents a framework that summarizes and deļ¬nes the characteristics that can drive complexity in a given environment. A subset of these characteristics were tested by 65 listeners who listened to the ARTE scenes (also with target speech), while answering a three-stage questionnaire. The analysis revealed that listenersā€™ perceived complexity is associated with both the loudness and the variability of the scenes. The ļ¬nal paper analyzes the responses of listeners to an open-ended auditory scene analysis task using ARTE, and the observed limitations are discussed. A concluding discussion dissects how the auditory system deals with realistic amounts of acoustic information.1 online resource (xix, 215 pages : illustrations

    Complex acoustic environments: concepts, methods and auditory perception

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    Thesis by publication.Bibliography: pages 191-215.1. Introduction -- 2. The ambisonic recordings of typical environments (ARTE) database -- 3. Conversational speech levels and signal-to-noise ratios in realistic conditions -- 4. Complex acoustic environments: review, framework and subjective model -- 5. Exploring the ability of listeners to identify events in realistic environments -- 6. General discussion and conclusions -- Appendices.In everyday life, the ears constantly receive information from the environment that is carried by sound waves. Despite the uncontrolled nature of this information, normal hearing listeners can make sense of the unstructured sounds. In contrast, hearing has mostly been studied using acoustic stimuli that are rigidly controlled. The difference between understanding such artiļ¬cial stimuli and real-world hearing has produced the distinction of ā€™complex acoustic environmentsā€˜ (CAEs) ā€“ a catch-all term for everything that the laboratory-based stimuli are not. However, an exact deļ¬nition has been elusive, despite growing use in hearing research ā€“ especially in research focusing on hearing-impaired individuals, who struggle communicating in cocktail-party like scenarios. In this work, several aspects of CAEs were studied with the intention to understand where the complexity lies. The work consists of four main parts in manuscript form. The ļ¬rst paper presents the Ambisonic Recordings of Typical Environments (ARTE) database, which contains 3D recordings of everyday scenarios. These were the primary stimuli used in all subsequent parts of this work. In the second paper, the speech and noise levels of real conversations were measured at two distances between talkers. The third paper reviews the origins and uses of the CAE concept in literature and presents a framework that summarizes and deļ¬nes the characteristics that can drive complexity in a given environment. A subset of these characteristics were tested by 65 listeners who listened to the ARTE scenes (also with target speech), while answering a three-stage questionnaire. The analysis revealed that listenersā€™ perceived complexity is associated with both the loudness and the variability of the scenes. The ļ¬nal paper analyzes the responses of listeners to an open-ended auditory scene analysis task using ARTE, and the observed limitations are discussed. A concluding discussion dissects how the auditory system deals with realistic amounts of acoustic information.1 online resource (xix, 215 pages : illustrations

    Behavioral dynamics of conversation, (mis)communication and coordination in noisy environments

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    Abstract During conversations people coordinate simultaneous channels of verbal and nonverbal information to hear and be heard. But the presence of background noise levels such as those found in cafes and restaurants can be a barrier to conversational success. Here, we used speech and motion-tracking to reveal the reciprocal processes people use to communicate in noisy environments. Conversations between twenty-two pairs of typical-hearing adults were elicited under different conditions of background noise, while standing or sitting around a table. With the onset of background noise, pairs rapidly adjusted their interpersonal distance and speech level, with the degree of initial change dependent on noise level and talker configuration. Following this transient phase, pairs settled into a sustaining phase in which reciprocal speech and movement-based coordination processes synergistically maintained effective communication, again with the magnitude of stability of these coordination processes covarying with noise level and talker configuration. Finally, as communication breakdowns increased at high noise levels, pairs exhibited resetting behaviors to help restore communicationā€”decreasing interpersonal distance and/or increasing speech levels in response to communication breakdowns. Approximately 78Ā dB SPL defined a threshold where behavioral processes were no longer sufficient for maintaining effective conversation and communication breakdowns rapidly increased
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