Acoustic Communication

Since the first edition was published seventeen years ago social and technical changes have altered the world of acoustic communication. This book draws upon many traditional disciplines that deal with specific aspects of sound, and presents material within an interdisciplinary framework. It establishes a model for understanding all acoustic and aural experiences both in their traditional forms and as they have been radically altered in the 20th century, Digital technology has completely redefined the listening and consumption patterns of sound. We are now able to benefit from the march of technology via a companion CD-ROM, which accompanies this volume for the first time.

In order to communicate, animals send and receive signals that are subject to their particular anatomical, psychological, and environmental constraints. This SHAR volume discusses both the production and perception of acoustic signals. Chapters address the information that animals communicate, how the communication is developed and learned, and how communication systems have adapted and evolved within species. The book will give examples from a variety of species.

The last decades have brought a significant increase in research on acoustic communi cation in animals. Publication of scientific papers on both empirical and theoretical aspects of this topic has greatly increased, and a new journal, Bioacoustics, is entirely devoted to such articles. Coupled with this proliferation of work is a recognition that many of the current issues are best approached with an interdisciplinary perspective, requiring technical and theoretical contributions from a number of areas of inquiry that have traditionally been separated. With the notable exception of a collection edited by Lewis (1983), there have been fewvolumes predominatelyfocused on technical issues in comparative bioacoustics to follow up the earlyworks edited by Lanyon and Tavolga (1960) and Busnel (1963). It was the tremendous growth of expertise c:()ncerning this topic in particular that provided the initial impetus to organize this volume, which attempts to present fundamental information from both theoretical and applied aspects of current bioacoustics research. While a completely comprehensive review would be impractical, this volume offers a basic treatment of a wide variety of topics aimed at providing a conceptual framework within which researchers can address their own questions. Each presentation is designed to be useful to the broadest possible spectrum of researchers, including both those currently working in any of the many and diverse disciplines of bioacoustics, and others that may be new to such studies.

This volume provides a comprehensive selection of recent studies addressing insect hearing and acoustic communication. The variety of signalling behaviours and hearing organs makes insects highly suitable animals for exploring and analysing signal generation and hearing in the context of neural processing, ecology, evolution and genetics. Across a variety of hearing species like moths, crickets, bush-crickets, grasshoppers, cicadas and flies, the leading researchers in the field cover recent scientific progress and address key points in current research, such as: - How can we approach the evolution of hearing in insects and what is the developmental and neural origin of the auditory organs? - How are hearing and sound production embedded in the natural lifestyle of the animals, allowing intraspecific communication but also predator avoidance and even predation? - What are the functional properties of hearing organs and how are they achieved at the molecular, biophysical and neural levels? - What are the neural mechanisms of central auditory processing and signal generation? The book is intended for students and researchers both inside and outside of the fascinating field of bioacoustics and aims to foster understanding of hearing and acoustic communication in insects.

Digital Underwater Acoustic Communications focuses on describing the differences between underwater acoustic communication channels and radio channels, discusses loss of transmitted sound in underwater acoustic channels, describes digital underwater acoustic communication signal processing, and provides a comprehensive reference to digital underwater acoustic communication equipment. This book is designed to serve as a reference for postgraduate students and practicing engineers involved in the design and analysis of underwater acoustic communications systems as well as for engineers involved in underwater acoustic engineering. Introduces the basics of underwater acoustics, along with the advanced functionalities needed to achieve reliable communications in underwater environment Identifies challenges in underwater acoustic channels relative to radio channels, underwater acoustic propagation, and solutions Shows how multi-path structures can be thought of as time diversity signals Presents a new, robust signal processing system, and an advanced FH-SS system for multimedia underwater acoustic communications with moderate communication ranges (above 20km) and rates (above 600bps) Describes the APNFM system for underwater acoustic communication equipment (including both civil and military applications), to be employed in active sonar to improve its performance

A blend of introductory material and advanced signal processing and communication techniques, of critical importance to underwater system and network development This book, which is the first to describe the processing techniques central to underwater OFDM, is arranged into four distinct sections: First, it describes the characteristics of underwater acoustic channels, and stresses the difference from wireless radio channels. Then it goes over the basics of OFDM and channel coding. The second part starts with an overview of the OFDM receiver, and develops various modules for the receiver design in systems with single or multiple transmitters. This is the main body of the book. Extensive experimental data sets are used to verify the receiver performance. In the third part, the authors discuss applications of the OFDM receiver in i) deep water channels, which may contain very long separated multipath clusters, ii) interference-rich environments, where an unintentional interference such as Sonar will be present, and iii) a network with multiple users where both non-cooperative and cooperative underwater communications are developed. Lastly, it describes the development of a positioning system with OFDM waveforms, and the progress on the OFDM modem development. Closely related industries include the development and manufacturing of autonomous underwater vehicles (AUVs) and scientific sensory equipment. AUVs and sensors in the future could integrate modems, based on the OFDM technology described in this book. Contents includes: Underwater acoustic channel characteristics/OFDM basics/Peak-to-average-ratio control/Detection and Doppler estimation (Doppler scale and CFO)/Channel estimation and noise estimation/A block-by-block progressive receiver and performance results/Extensions to multi-input multi-output OFDM/Receiver designs for multiple users/Cooperative underwater OFDM (Physical layer network coding and dynamic coded cooperation)/Localization with OFDM waveforms/Modem developments A valuable resource for Graduate and postgraduate students on electrical engineering or physics courses; electrical engineers, underwater acousticians, communications engineers

Information is a core concept in animal communication: individuals routinely produce, acquire, process and store information, which provides the basis for their social life. This book focuses on how animal acoustic signals code information and how this coding can be shaped by various environmental and social constraints. Taking birds and mammals, including humans, as models, the authors explore such topics as communication strategies for “public” and “private” signaling, static and dynamic signaling, the diversity of coded information and the way information is decoded by the receiver. The book appeals to a wide audience, ranging from bioacousticians, ethologists and ecologists to evolutionary biologists. Intended for students and researchers alike, it promotes the idea that Shannon and Weaver’s Mathematical Theory of Communication still represents a strong framework for understanding all aspects of the communication process, including its dynamic dimensions.

Walk near woods or water on any spring or summer night and you will hear a bewildering (and sometimes deafening) chorus of frog, toad, and insect calls. How are these calls produced? What messages are encoded within the sounds, and how do their intended recipients receive and decode these signals? How does acoustic communication affect and reflect behavioral and evolutionary factors such as sexual selection and predator avoidance? H. Carl Gerhardt and Franz Huber address these questions among many others, drawing on research from bioacoustics, behavior, neurobiology, and evolutionary biology to present the first integrated approach to the study of acoustic communication in insects and anurans. They highlight both the common solutions that these very different groups have evolved to shared challenges, such as small size, ectothermy (cold-bloodedness), and noisy environments, as well as the divergences that reflect the many differences in evolutionary history between the groups. Throughout the book Gerhardt and Huber also provide helpful suggestions for future research.