Download or read book Directivity Patterns for Room Acoustical Measurements and Simulations written by Martin Pollow and published by Logos Verlag Berlin GmbH. This book was released on 2015-09-09 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acoustics of rooms can be objectively described by the room impulse responses obtained for given transfer paths using measurement or simulation. In practice, the directionally dependent behavior of sources and receivers is often disregarded and thus assumed to be of omnidirectional type. In reality, however, these sources and receivers have specific directivity patterns, which are reported to induce audible differences. In this work a methodology to capture, analyze and process directivity patterns of sources and receivers is described. With the help of surrounding spherical microphone and loudspeaker arrays these directivity patterns are measured to be used in room acoustic applications. Room impulse responses with respect to specific directivity patterns can be realized using compact loudspeaker arrays with known directivity. Applying the results of directivity superposition to the set of measured room impulse responses, the acoustics for specific directivity patterns are found. Using a simulation of the room instead, source and receiver directivity patterns can be included in both wave based and particle based methods. The results of this work facilitate more authentic descriptions of room acoustics for specific source and receiver directivity patterns.
Download or read book Software Based Acoustical Measurements written by Federico Miyara and published by Springer. This book was released on 2017-05-26 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Acoustical Measurements written by Leo Leroy Beranek and published by Acoustical Society of Amer. This book was released on 1988 with total page 841 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Acoustical Techniques for the Measurement of Mechanical Properties written by and published by Elsevier. This book was released on 2001-10-16 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides an overview of modern acoustical techniques for the measurement of mechanical properties. Chapters include Fundamentals of Elastic Constants; Point Source/Point Receiver Methods; Laser Controlled Surface Acoustic Waves; Quantitative Acoustical Microscopy of Solids; Resonant Ultrasound Spectroscopy; Elastic Properties and Thermodynamics; Sound Speed as a Thermodynamic Property of Fluids; Noninvasive Determination of Sound Speed in Liquids; Introduction to the Elastic Constants of Gases; and Acoustic Measurement in Gases.
Download or read book Influences of external error sources on measurements of room acoustic parameters written by Martin Guski and published by Logos Verlag Berlin GmbH. This book was released on 2015-11-30 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Correct and precise measurements of room acoustic parameters are of fundamental importance for subjective room impression characterization and for the physical description of the sound field. This thesis investigates external influences on acoustic measurements and errors of the resulting room acoustic parameters. Theoretical models have been developed to predict these errors and indicate the tolerable limits of the described influences. To validate these models, specially designed room acoustic measurements that separate the individual influence factors have been conducted. Noise has been identified as one of the main influence factors and occurs during every measurement. In this thesis the performance of five commonly used stationary noise compensation methods are systematically analyzed depending on the peak signal-to-noise ratio. Impulsive noise that could also occur during the measurement is investigated separately, as the previously introduced compensation techniques are unsuited to handle the influence. The second part of this thesis analyzes the influence of time variances during measurements. Inter- and intra-measurement temperature changes, air movement, and human-sized scattering objects have been investigated.
Download or read book Acoustical Evaluation of the NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel written by Milo D. Dahl and published by . This book was released on 1992 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Signal Processing in Audio and Acoustical Engineering written by Francis F. Li and published by CRC Press. This book was released on 2019-04-02 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starting with essential maths, fundamentals of signals and systems, and classical concepts of DSP, this book presents, from an application-oriented perspective, modern concepts and methods of DSP including machine learning for audio acoustics and engineering. Content highlights include but are not limited to room acoustic parameter measurements, filter design, codecs, machine learning for audio pattern recognition and machine audition, spatial audio, array technologies and hearing aids. Some research outcomes are fed into book as worked examples. As a research informed text, the book attempts to present DSP and machine learning from a new and more relevant angle to acousticians and audio engineers. Some MATLAB® codes or frameworks of algorithms are given as downloads available on the CRC Press website. Suggested exploration and mini project ideas are given for "proof of concept" type of exercises and directions for further study and investigation. The book is intended for researchers, professionals, and senior year students in the field of audio acoustics.
Download or read book Improved Acoustical Treatment for Engine Test Stands written by John T. Welbourn and published by . This book was released on 1963 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes an investigation and test of improved materials, noise control devices, and methods of application to engine test stands for the purpose ocing radiated noise and in creasing structural durability. Included are excerpts from an acoustical survey of a modified test stand and a full report of the acoustical evaluation of experimental exhaust units for a Transportable Turbojet Engine Test Stand. Exper imental work was performed at Wright-Patterson Air Force Base, Ohio. (Author).
Download or read book Acoustical Materials written by Pranab Saha and published by SAE International. This book was released on 2021-08-11 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is acoustics? What is noise? How is sound measured? How can the vehicle noise be reduced using sound package treatments? Pranab Saha answers these and more in Acoustical Materials. Acoustics is the science of sound, including its generation, propagation, and effect. Although the propulsion sources of internal combustion engine (ICE) vehicles and electric motor-powered vehicles (EV) are different and therefore their propulsion noises are different, both types of vehicles have shared noise concerns: Tire and road noise Wind noise Vehicle noise and vibration issues have been there almost from the inception of vehicle manufacturing. The noise problem in a vehicle is very severe and is difficult to solve only by modifying the sources of noise and vibration. Sound package treatments address the noise and vibration issues along the path to reduce in-cabin noise. In Acoustical Materials, readers will grasp the science of reducing sound and vibration using sound absorbers, sound barriers, and vibration dampers. Sound provides information on the proper operation of the vehicle, but if unchecked, can detract from the consumer experience within the vehicle and create noise pollution outside the vehicle. Acoustical Materials provides essential information on the basics of sound, vehicle noise source, how these are measured, how vehicle owners perceive sound, and ultimately, how to solve noise problems in vehicles using sound package materials.
Download or read book Measuring Directional Velocity in Water Waves with an Acoustic Flowmeter written by R. H. Multer and published by . This book was released on 1970 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Acoustical Oceanography written by Herman Medwin and published by Academic Press. This book was released on 1997-11-05 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: The developments in the field of ocean acoustics over recent years make this book an important reference for specialists in acoustics, oceanography, marine biology, and related fields. Fundamentals of Acoustical Oceanography also encourages a new generation of scientists, engineers, and entrepreneurs to apply the modern methods of acoustical physics to probe the unknown sea. The book is an authoritative, modern text with examples and exercises. It contains techniques to solve the direct problems, solutions of inverse problems, and an extensive bibliography from the earliest use of sound in the sea to present references.Written by internationally recognized scientists, the book provides background to measure ocean parameters and processes, find life and objects in the sea, communicate underwater, and survey the boundaries of the sea. Fundamentals of Acoustical Oceanography explains principles of underwater sound propagation, and describes how both actively probing sonars and passively listening hydrophones can reveal what the eye cannot see over vast ranges of the turbid ocean. This book demonstrates how to use acoustical remote sensing, variations in sound transmission, in situ acoustical measurements, and computer and laboratory models to identify the physical and biological parameters and processes in the sea. * Offers an integrated, modern approach to passive and active underwater acoustics* Contains many examples of laboratory scale models of ocean-acoustic environments, as well as descriptions of experiments at sea* Covers remote sensing of marine life and the seafloor* Includes signal processing of ocean sounds, physical and biological noises at sea, and inversions* resents sound sources, receivers, and calibration* Explains high intensities; explosive waves, parametric sources, cavitation, shock waves, and streaming* Covers microbubbles from breaking waves, rainfall, dispersion, and attenuation* Describes sound propagation along ray paths and caustics* Presents sound transmissions and normal mode methods in ocean waveguides
Download or read book Acoustical Engineering written by Harry Ferdinand Olson and published by . This book was released on 1957 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustical Measurements written by Leo L. Beranek and published by Amer Inst of Physics. This book was released on 1993 with total page 841 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Textiles written by Rajiv Padhye and published by Springer. This book was released on 2016-10-26 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Uncertainties in Acoustical Transfer Functions written by Pascal Dietrich and published by Logos Verlag Berlin GmbH. This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measured transfer functions of acoustic systems are often used to derive single-number parameters. The uncertainty analysis is commonly focused on the derived parameters but not on the transfer function as the primary quantity. This thesis presents an approach to assess the uncertainty contributions in these transfer functions by using analytic models. Uncertainties caused by the measurement method are analyzed with a focus on the underlying signal processing. In particular, the influence of nonlinearities in the acoustic measurement chain are modeled to predict artifacts in the measured signals and hence the calculated acoustic transfer function. Secondly, characterization methods commonly applied in the field of signal processing are linked to the acoustic scenarios and the main influencing parameters. Acoustic parameters are then derived analytically and by means of Monte Carlo simulations considering the uncertainty of these input parameters. In order to provide airborne applications, analytic models for sound barrier and room acoustic measurements are developed incorporating the directivity and the orientation of the sound source as well as the positions of sources and receivers. The simulated uncertainty contributions are validated by measurements. The same approach is also applied to structure-borne sound applications.
Download or read book Publications of the National Bureau of Standards 1977 Catalog written by United States. National Bureau of Standards and published by . This book was released on 1978 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predicting Outdoor Sound written by Keith Attenborough and published by CRC Press. This book was released on 2006-11-17 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting Outdoor Sound provides a scholarly yet practical examination of the phenomena that affect outdoor sound close to the ground and its prediction. It is devoted to bringing together theories and data to give both researchers and practitioners the basis for deciding which model to use in a given situation. The book covers recent advances in