Listening With Two Ears New Insights And Perspectives In Binaural Research

Hearing is dependent on neural processing of acoustic cues obtained by the left and right ears. Neural signals driven by the two ears are integrated at multiple levels of the central auditory system, which enables animals including humans to perform various functions including localization of a sound source. A natural listening environment typically contains sounds from multiple sources. These sounds can have different spectral and temporal features and occur at either the same or different time. Integration can happen among neural signals elicited by the same or different sounds. The way of integration can greatly affect how individual sounds are sensed and perceived. Functions such as auditory grouping and stream segregation, which are central to establishing coherent auditory images in a complex listening environment, are highly dependent on the way of integration. Binaural hearing is complicated by individual differences and developmental changes in head and pinna shape/size as binaural cues can be affected by these differences and changes. Furthermore, neural processing of binaural cues can be influenced by hearing impairments and the use of hearing aids and cochlear implants. These factors likely require a listener to optimize the use of binaural cues through learning and to use plastic changes in the nervous system to perform the optimization. Great strides have been made in understanding binaural processing in normal and impaired auditory systems. This Research Topic aims to highlight some of the latest findings in the following areas: 1) Animal behavioral and human psychoacoustical studies of binaural hearing; 2) Neural encoding and processing of binaural cues and structural as well as neurophysiological bases of such encoding and processing; 3) Contribution of binaural neural processing to auditory functions such as sound-source localization, binaural fusion, binaural interference, spatial release from masking, auditory grouping, and auditory stream segregation; 4) Computational models of binaural processing; 5) Learning and plastic changes in binaural processing following hearing loss or alterations of acoustic environment and structural as well as physiological bases of these behavioral changes; 6) Clinical aspects of binaural processing including application of processing strategies, including research on the benefits of bilateral cochlear implantation, and the neural correlates thereof

Sound, devoid of meaning, would not matter to us. It is the information sound conveys that helps the brain to understand its environment. Sound and its underlying meaning are always associated with time and space. There is no sound without spatial properties, and the brain always organizes this information within a temporal–spatial framework. This book is devoted to understanding the importance of meaning for spatial and related further aspects of hearing, including cross-modal inference. People, when exposed to acoustic stimuli, do not react directly to what they hear but rather to what they hear means to them. This semiotic maxim may not always apply, for instance, when the reactions are reflexive. But, where it does apply, it poses a major challenge to the builders of models of the auditory system. Take, for example, an auditory model that is meant to be implemented on a robotic agent for autonomous search-&-rescue actions. Or think of a system that can perform judgments on the sound quality of multimedia-reproduction systems. It becomes immediately clear that such a system needs • Cognitive capabilities, including substantial inherent knowledge • The ability to integrate information across different sensory modalities To realize these functions, the auditory system provides a pair of sensory organs, the two ears, and the means to perform adequate preprocessing of the signals provided by the ears. This is realized in the subcortical parts of the auditory system. In the title of a prior book, the term Binaural Listening is used to indicate a focus on sub-cortical functions. Psychoacoustics and auditory signal processing contribute substantially to this area. The preprocessed signals are then forwarded to the cortical parts of the auditory system where, among other things, recognition, classification, localization, scene analysis, assignment of meaning, quality assessment, and action planning take place. Also, information from different sensory modalities is integrated at this level. Between sub-cortical and cortical regions of the auditory system, numerous feedback loops exist that ultimately support the high complexity and plasticity of the auditory system. The current book concentrates on these cognitive functions. Instead of processing signals, processing symbols is now the predominant modeling task. Substantial contributions to the field draw upon the knowledge acquired by cognitive psychology. The keyword Binaural Understanding in the book title characterizes this shift. Both books, The Technology of Binaural Listening and the current one, have been stimulated and supported by AABBA, an open research group devoted to the development and application of models of binaural hearing. The current book is dedicated to technologies that help explain, facilitate, apply, and support various aspects of binaural understanding. It is organized into five parts, each containing three to six chapters in order to provide a comprehensive overview of this emerging area. Each chapter was thoroughly reviewed by at least two anonymous, external experts. The first part deals with the psychophysical and physiological effects of Forming and Interpreting Aural Objects as well as the underlying models. The fundamental concepts of reflexive and reflective auditory feedback are introduced. Mechanisms of binaural attention and attention switching are covered—as well as how auditory Gestalt rules facilitate binaural understanding. A general blackboard architecture is introduced as an example of how machines can learn to form and interpret aural objects to simulate human cognitive listening. The second part, Configuring and Understanding Aural Space, focuses on the human understanding of complex three-dimensional environments—covering the psychological and biological fundamentals of auditory space formation. This part further addresses the human mechanisms used to process information and interact in complex reverberant environments, such as concert halls and forests, and additionally examines how the auditory system can learn to understand and adapt to these environments. The third part is dedicated to Processing Cross-Modal Inference and highlights the fundamental human mechanisms used to integrate auditory cues with cues from other modalities to localize and form perceptual objects. This part also provides a general framework for understanding how complex multimodal scenes can be simulated and rendered. The fourth part, Evaluating Aural-scene Quality and Speech Understanding, focuses on the object-forming aspects of binaural listening and understanding. It addresses cognitive mechanisms involved in both the understanding of speech and the processing of nonverbal information such as Sound Quality and Quality-of- Experience. The aesthetic judgment of rooms is also discussed in this context. Models that simulate underlying human processes and performance are covered in addition to techniques for rendering virtual environments that can then be used to test these models. The fifth part deals with the Application of Cognitive Mechanisms to Audio Technology. It highlights how cognitive mechanisms can be utilized to create spatial auditory illusions using binaural and other 3D-audio technologies. Further, it covers how cognitive binaural technologies can be applied to improve human performance in auditory displays and to develop new auditory technologies for interactive robots. The book concludes with the application of cognitive binaural technologies to the next generation of hearing aids.

Binaural interference occurs when the speech input to one ear interferes with the input to the other ear during binaural stimulation. The first published study on binaural interference twenty-five years ago demonstrated that some individuals, particularly older individuals, perform more poorly with two hearing aids than with one and/or more poorly with binaural than monaural stimulation on electrophysiologic as well as behavioral measures. Binaural interference is relevant to every audiologist because it impacts the successful use of binaural hearing aids and may explain communicative difficulty in noise or other challenging listening situations in persons with normal-hearing sensitivity as well as persons with hearing loss. This exciting new book written by two highly respected audiologists first traces the history of its study by researchers, then reviews the evidence, both direct and indirect, supporting its reality. This is followed by a discussion of the possible causes of the phenomenon and in-depth analysis of illustrative cases. The authors outline a systematic approach to the clinical detection, evaluation and amelioration of individuals who exhibit binaural interference. Suggestions are furnished on improved techniques for evaluation of the binaural advantage in general and on sensitized detection of the disorder in particular. The book ends with recommendations for future directions. Given the adverse impact of binaural interference on auditory function and its occurrence in a significant subset of the population with hearing loss, as well as in some individuals with normal-hearing sensitivity, research on binaural interference only recently has begun to flourish, and adaptation of audiologic clinical practice to identify, assess, and manage individuals with binaural interference has yet to become widespread. The authors intend for the book to provide impetus for pursuing further research and to encourage audiologists to exp

Perspectives on Auditory Research celebrates the last two decades of the Springer Handbook in Auditory Research. Contributions from the leading experts in the field examine the progress made in auditory research over the past twenty years, as well as the major questions for the future.

The field of Binaural Hearing involves studies of auditory perception, physiology, and modeling, including normal and abnormal aspects of the system. Binaural processes involved in both sound localization and speech unmasking have gained a broader interest and have received growing attention in the published literature. The field has undergone some significant changes. There is now a much richer understanding of the many aspects that comprising binaural processing, its role in development, and in success and limitations of hearing-aid and cochlear-implant users. The goal of this volume is to provide an up-to-date reference on the developments and novel ideas in the field of binaural hearing. The primary readership for the volume is expected to be academic specialists in the diverse fields that connect with psychoacoustics, neuroscience, engineering, psychology, audiology, and cochlear implants. This volume will serve as an important resource by way of introduction to the field, in particular for graduate students, postdoctoral scholars, the faculty who train them and clinicians.

Mental chronometry encompasses all aspects of time processing in the nervous system and constitutes a standard tool in many disciplines including theoretical and experimental psychology and human neuroscience. Mental chronometry has represented a fundamental approach to elucidate the time course of many cognitive phenomena and their underlying neural circuits over more than a century. Nowadays, mental chronometry continues evolving and expanding our knowledge, and our understanding of the temporal organization of the brain in combination with different neuroscience techniques and advanced methods in mathematical analysis. In research on mental chronometry, human reaction/responses times play a central role. Together with reaction times, other topics in mental chronometry include vocal, manual and saccadic latencies, subjective time, psychological time, interval timing, time perception, internal clock, time production, time representation, time discrimination, time illusion, temporal summation, temporal integration, temporal judgment, redundant signals effect, perceptual, decision and motor time, etc. The aim of this research topic is to provide an overview of the state of the art in this field?its relevance, recent findings, current challenges, perspectives and future directions. Thus, as a result, a collection of 14 original research and opinion papers from different experts have been gathered together in a single volume. We hope this research topic will provide a useful framework and an up-to-date set of papers for further discussion on mental chronometry within the human brain. We are grateful to all the referees for their valuable support, effort, and time during the creation of the research topic. Granada, April 2015 José M Medina Willy Wong José A Díaz Hans Colonius

This book gathers together state-of-the-art perspectives on topics spanning speech processing, psychophysics, anatomy, physiology, hearing impairment, and speech pathology. It is genuinely cross disciplinary over speech and hearing spectrum or research.

Signal Processing in Auditory Neuroscience: Temporal and Spatial Features of Sound and Speech discusses how the physical attributes of different sounds manifest in neural signals and how to tease-apart their different influences. It includes EEG/MEG as additional variables to be considered when studying neural mechanisms of auditory processing in general, specifically in speech. Focuses on signal processing in human auditory-neuroscience Contains information that will be useful to researchers using a MEG/EEG recording of brain activity to study neural mechanisms of auditory processing and speech Gives an important overview and methodological background for techniques that are useful in human auditory-neuroscience