This book provides a comprehensive introduction to the theory and practice of spherical microphone arrays, and was written for graduate students, researchers and engineers who work with spherical microphone arrays in a wide range of applications. The new edition includes additions and modifications, and references supplementary Matlab code to provide the reader with a straightforward start for own implementations. The book is also accompanied by a Matlab manual, which explains how to implement the examples and simulations presented in the book. The first two chapters provide the reader with the necessary mathematical and physical background, including an introduction to the spherical Fourier transform and the formulation of plane-wave sound fields in the spherical harmonic domain. In turn, the third chapter covers the theory of spatial sampling, employed when selecting the positions of microphones to sample sound pressure functions in space. Subsequent chapters highlight various spherical array configurations, including the popular rigid-sphere-based configuration. Beamforming (spatial filtering) in the spherical harmonics domain, including axis-symmetric beamforming, and the performance measures of directivity index and white noise gain are introduced, and a range of optimal beamformers for spherical arrays, including those that achieve maximum directivity and maximum robustness are developed, along with the Dolph-Chebyshev beamformer. The final chapter discusses more advanced beamformers, such as MVDR (minimum variance distortionless response) and LCMV (linearly constrained minimum variance) types, which are tailored to the measured sound field. Mathworks kindly distributes the Matlab sources for this book on https://www.mathworks.com/matlabcentral/fileexchange/68655-fundamentals-of-spherical-array-processing.

This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

Electroacoustic transducers (EAT) are devices, which transform electric energy to energy of acoustic fluctuations. Principles of action, design of transducers for work in air and water as well as for non-destructive control are described in the book. New technologies of designing EAT, not only expanding designing possibilities, are described. They also allow to create transducers with improved characteristics. In particular, methods to increase target capacity (sound pressure), decrease working (resonant) frequency of transducers and expand frequencies of projectors and sound receivers are developed. Methods and control units of transducers in batch production of transducers are described, too.

This book highlights the symmetry properties of acoustic fields and describes the gauge invariance approach, which can be used to reveal those properties. Symmetry is the key theoretical framework of metamaterials, as has been demonstrated by the successful fabrication of acoustical metamaterials. The book first provides the necessary theoretical background, which includes the covariant derivative, the vector potential, and invariance in coordinate transformation. This is followed by descriptions of global gauge invariance (isotropy), and of local gauge invariance (anisotropy). Sections on time reversal symmetry, reflection invariance, and invariance of finite amplitude waves round out the coverage.

This collection analyses various European rural locations through a relational lens, attending to key aspects and dimensions of the 'relational rurals' such as cooperation, contestation, solidarity and consensus. By observing rural settings in such terms, contributors are able to rethink European rurality from a distinctly relational perspective.

Describes the properties of cellular membranes and their relationship with fundamental biological processes. This book provides insight on the chemistry, structures, model systems, and techniques employed for studying membrane properties and processes. A major focus is on the prominence of membranes in diverse physiological processes and disease, as well as applications of membranes and biomimetic membrane systems in varied disciplines. The book aims to illuminate the significance and beauty of membrane science, and serve both as an entry point for scholars wishing to embark on membrane research, as well as scientists already working in the field.

This textbook provides a detailed introduction to the use of software in combination with simple and economical hardware (a sound level meter with calibrated AC output and a digital recording system) to obtain sophisticated measurements usually requiring expensive equipment. It emphasizes the use of free, open source, and multiplatform software. Many commercial acoustical measurement systems use software algorithms as an integral component; however the methods are not disclosed. This book enables the reader to develop useful algorithms and provides insight into the use of digital audio editing tools to document features in the signal. Topics covered include acoustical measurement principles, in-depth critical study of uncertainty applied to acoustical measurements, digital signal processing from the basics, and metrologically-oriented spectral and statistical analysis of signals. The student will gain a deep understanding of the use of software for measurement purposes; the ability to implement software-based measurement systems; familiarity with the hardware necessary to acquire and store signals; an appreciation for the key issue of long-term preservation of signals; and a full grasp of the often neglected issue of uncertainty in acoustical measurements. Pedagogical features include in-text worked-out examples, end-of-chapter problems, a glossary of metrology terms, and extensive appendices covering statistics, proofs, additional examples, file formats, and underlying theory.

This book offers an overview of models, measurements, calculations and examples connecting musical acoustics and music psychology. Indeed, many mathematical formulations that explain musical acoustics can also be used to help predict human auditory perception.

Control of Noise and Structural Vibration presents a MATLAB (R)-based approach to solving the problems of undesirable noise generation and transmission by structures and of undesirable vibration within structures in response to environmental or operational forces. The fundamentals of acoustics, vibration and coupling between vibrating structures and the sound fields they generate are introduced including a discussion of the finite element method for vibration analysis. Following this, the treatment of sound and vibration control begins, illustrated by example systems such as beams, plates and double walls. Sensor and actuator placement is explained as is the idea of modal sensor-actuators. The design of appropriate feedback systems includes consideration of basic stability criteria and robust active structural acoustic control. Positive position feedback (PPF) and multimode control are also described in the context of loudspeaker-duct and loudspeaker-microphone models. The design of various components is detailed including the analog circuit for PPF, adaptive (semi-active) Helmholtz resonators and shunt piezoelectric circuits for noise and vibration suppression. The text makes extensive use of MATLAB (R) examples and these can be simulated using files available for download from the book's webpage at springer.com. End-of-chapter exercises will help readers to assimilate the material as they progress through the book. Control of Noise and Structural Vibration will be of considerable interest to the student of vibration and noise control and also to academic researchers working in the field. It's tutorial features will help practitioners who wish to update their knowledge with self-study.

Signal and Acoustic Modeling for Speech and Communication Disorders demonstrates how speech signal processing and acoustic modeling can be instrumental in early detection and successful intervention with speech deficits resulting from Parkinson's disease, Autism Spectrum disorder, cleft palate, intellectual disabilities, and neuro-motor impairments. Utilizing some of the most advanced methods in signal and acoustic modeling, this eminent group of contributors show how such technologies can inure to the benefit of healthcare and to society writ large. Paradoxically, what most of us take for granted still remains a Sisyphean battle for those with speech and language disorders, who struggle every day to make themselves heard and understood. The purpose of this book is to stimulate a vibrant discussion among speech scientists, system designers, and practitioners on how to best marshal the latest advances in signal and acoustic modeling to address some of the most challenging speech and communication disorders affecting a wide variety of patient populations across the world.

"Acoustics: Sound Fields and Transducers "is a thoroughly updated version of Leo Beranek's classic 1954 book that retains and expands on the original's detailed acoustical fundamentals while adding practical formulas and simulation methods.

Serving both as a text for students in engineering departments and as a reference for practicing engineers, this book focuses on electroacoustics, analyzing the behavior of transducers with the aid of electro-mechano-acoustical circuits. Assuming knowledge of electrical circuit theory, it starts by guiding readers through the basics of sound fields, the laws governing sound generation, radiation, and propagation, and general terminology. It then moves on to examine: Microphones (electrostatic and electromagnetic), electrodynamic loudspeakers, earphones, and hornsLoudspeaker enclosures, baffles, and waveguidesMiniature applications (e.g., MEMS in I-Pods and cellphones)Sound in enclosures of all sizes, such as school rooms, offices, auditoriums, and living rooms

Numerical examples and summary charts are given throughout the text to make the material easily applicable to practical design. It is a valuable resource for experimenters, acoustical consultants, and to those who anticipate being engineering designers of audio equipment.
An update for the digital age of Leo Beranek's classic 1954 book "Acoustics"Provides detailed acoustic fundamentals, enabling better understanding of complex design parameters, measurement methods, and dataExtensive appendices cover frequency-response shapes for loudspeakers, mathematical formulas, and conversion factors