Download or read book Impulse Acoustic Measurements written by J. D. Warren and published by . This book was released on 1968 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acoustic Impulse Reverberation Measurements written by Herbert V. Nussey and published by . This book was released on 1971 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directional Room Impulse Response Measurement written by Johannes Klein and published by . This book was released on 2020-07-28 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measured room impulse responses are inextricably linked with the distinct directivity patterns of the applied sources and receivers. In room acoustic measurements, the directivity is often disregarded or intentionally smoothed, waiving detailed information about single reflection paths, also denying the possibility of analyzing and auralizing the acoustic scene in relation to specific real-world sources and receivers. The measurement of directional room impulse responses as a set of measurements with unique directivity patterns can compensate for these shortcomings, retaining the information about the acoustic properties of a room in connection with directional information. Ideally, a directional room impulse response measurement consists of a single session and allows for the flexibility of choosing the desired directivity patterns in post-processing by combining different impulse response sub-sets. Such a procedure requires specialized measurement arrays. The lack of knowledge about the required level of directional detail, physical constraints of the array construction, and expected measurement artifacts hinder and feed-back into the development of the instruments and methods. This thesis explores these requirements and limits, focusing primarily on the design of suitable sources allowing for directional room impulse response measurement procedures with variable directivity.

Download or read book Impulse Measurements on Tubular Acoustic Systems written by A. P. Watson and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model Based Signal Enhancement for Impulse Response Measurement written by Xun Wang and published by Logos Verlag Berlin GmbH. This book was released on 2014 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impulse response measurements that are performed outdoors are highly susceptible to the uncertainties caused by the non-perfect measurement setup, the presence of background noise, and fluctuations in media such as wind and temperature drift. This work concentrates on two scenarios: the measurement of reflection coefficients of noise barriers and the influence of temperature variances in machinery cavities. Regarding the sound barrier measurement outdoors, a linear four-microphone array can be used to separate direct sound and reflected sound if the sound barrier does not include complicated scattering structures. With regard to the impulse response of an air-borne sound measurement for a machine monitoring system, a time-warping model for inter-period and intra-period temperature variances is investigated.

Download or read book Theoretical and Computational Acoustics 99 written by Ding Lee and published by World Scientific. This book was released on 2004-01-01 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ICTCA conference provides an interdisciplinary forum for active researchers in academia and industry who are of varying backgrounds to discuss the state-of-the-art developments and results in theoretical and computational acoustics and related topics. The papers presented at the meeting cover acoustical problems of common interest across disciplines and their accurate mathematical and numerical modelling. The present book collects papers that were presented at the 4th meeting and printed in the Journal of Computational Acoustics . There are about 120 full research articles on various subjects, such as wave propagation theory and numerical modelling, sound propagation, vibrations and noise generation, underwater acoustics, engineering seismology, ultrasonic field synthesis and modelling, as well as computational methods, inverse problems and tomography, shallow water acoustics and environmental/bottom parameter extraction. A CD-Rom is attached that allows readers to browse through articles and print those of interest to them. Contents: Wave Propagation Theory; Sound Propagation, Vibrations and Noise; Underwater Acoustics; Engineering Seismology; Ultrasonic Field Synthesis and Modelling; Computational Methods; Finite Elements for Wave Problems; Wave Propagation Modelling; Inverse Problems and Tomography; Geoacoustic Inversion in Shallow Water. Readership: Researchers and engineers in applied acoustics.

Download or read book A Sound Engineer s Guide to Audio Test and Measurement written by Glen Ballou and published by Taylor & Francis. This book was released on 2009 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a quick guide and complete reference to the fundamentals of test and measurement for all aspects of sound engineering. Including electrical and acoustic testing, measurement systems, levels, methods, protecting the ear, units of measurement and standards, this guide comes with and multiple tables to ensure quick easy access to information and illustrate points this is a must have reference for all audio engineers.

Download or read book An Investigation of Acoustic Impulse Response Measurement and Modeling for Small Rooms written by Zhixin Chen and published by . This book was released on 2007 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Room impulse response modeling has been a subject of interest to acousticians, musicians, and architects for many years. Room impulse response modeling can help to predict the acoustical characteristics of the new finished concert halls, to create a virtual studio effect for music production without building the actual studio room, and to compare the effect of different absorbing materials and treatments in architecture. The goals of this dissertation are to obtain a better match between the simulation and the measurement results of small room impulse responses, and to understand why the models and the measurements may differ even for simple cases like small rectangular rooms. The basic image source method and digital waveguide mesh are widely used in modeling small room impulse responses because they are relatively easy to implement.

Download or read book Handbook for Sound Engineers written by Glen Ballou and published by CRC Press. This book was released on 2015-03-05 with total page 2834 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook for Sound Engineers is the most comprehensive reference available for audio engineers, and is a must read for all who work in audio. With contributions from many of the top professionals in the field, including Glen Ballou on interpretation systems, intercoms, assistive listening, and fundamentals and units of measurement, David Miles Huber on MIDI, Bill Whitlock on audio transformers and preamplifiers, Steve Dove on consoles, DAWs, and computers, Pat Brown on fundamentals, gain structures, and test and measurement, Ray Rayburn on virtual systems, digital interfacing, and preamplifiers, Ken Pohlmann on compact discs, and Dr. Wolfgang Ahnert on computer-aided sound system design and room-acoustical fundamentals for auditoriums and concert halls, the Handbook for Sound Engineers is a must for serious audio and acoustic engineers. The fifth edition has been updated to reflect changes in the industry, including added emphasis on increasingly prevalent technologies such as software-based recording systems, digital recording using MP3, WAV files, and mobile devices. New chapters, such as Ken Pohlmann’s Subjective Methods for Evaluating Sound Quality, S. Benjamin Kanters’s Hearing Physiology—Disorders—Conservation, Steve Barbar’s Surround Sound for Cinema, Doug Jones’s Worship Styles in the Christian Church, sit aside completely revamped staples like Ron Baker and Jack Wrightson’s Stadiums and Outdoor Venues, Pat Brown’s Sound System Design, Bob Cordell’s Amplifier Design, Hardy Martin’s Voice Evacuation/Mass Notification Systems, and Tom Danley and Doug Jones’s Loudspeakers. This edition has been honed to bring you the most up-to-date information in the many aspects of audio engineering.

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 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 Measurement of Impulse Noise written by Hans G. Jonasson and published by . This book was released on 1997 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some problems with the current international standards for determination of emission sound pressure levels and sound power levels of impulse noise are dealt with. The concept of sound energy level is analysed theoretically and a series of measurements is reported. The results clearly indicate that sound energy levels can be determined using the same methods and having the same measurement uncertainty as have the sound power levels. There is no reason not to revise the relevant EN ISO standards to include the sound energy level. The measurement uncertainty of impulse noise is discussed and measurement results using both a real sound source and a loudspeaker emitting different sound pulses in different test environments are reported. The results indicate that C- weighted peak sound pressure levels of impulse sound can always be measured with good accuracy at short distances, about 0,5 m, from the sound source. The error in relation to hemi-anechoic measurements is not likely to exceed 2 dB. At larger distances larger errors may occur. However. it is possible to distinguish small errors from possible large errors by evaluating the indicator LpCpeak- LpCFn-ax The indicator shall be determined in the direct sound field of the source where reflections from the walls have little influence. A suitable measurement distance is 0,5 m. If this indicator is larger than 20 dB the measurement distance can be extended to about 3 m without exceeding an error of 2 dB in relation to hemi-anechoic measurements. The error in peak measurements will be smaller in the middle of a room than in a corner or close to walls.

Download or read book Acoustical Impulse Response Functions of Music Performance Halls written by Douglas Frey and published by Morgan & Claypool Publishers. This book was released on 2013-04-01 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital measurement of the analog acoustical parameters of a music performance hall is difficult. The aim of such work is to create a digital acoustical derivation that is an accurate numerical representation of the complex analog characteristics of the hall. The present study describes the exponential sine sweep (ESS) measurement process in the derivation of an acoustical impulse response function (AIRF) of three music performance halls in Canada. It examines specific difficulties of the process, such as preventing the external effects of the measurement transducers from corrupting the derivation, and provides solutions, such as the use of filtering techniques in order to remove such unwanted effects. In addition, the book presents a novel method of numerical verification through mean-squared error (MSE) analysis in order to determine how accurately the derived AIRF represents the acoustical behavior of the actual hall.

Download or read book Measurement and Analysis of the Impulse Response of Acoustic Systems written by Simone Geroso and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Impulse Noise written by Jarl Olofsson and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the frame of a Nordtest project sound energy levels and C-weighted peak sound pressure levels emitted by an artificial source emitting different impulse sounds have been measured by four Nordic laboratories in different test environments. The results indicate that sound energy levels can be determined with equal accuracy in hemi-anechoic, for hemi-spherical measurement surfaces, and reverberant test environments. They also indicate that C-weighted peak sound pressure levels measured at work places show little dependence on the acoustic environment as long as the indicator, LpCFmax, measured at 0,5m distance from the source, is larger than about 20 dB. If that condition is fulfilled the standard deviation of the reproducibility is about 1 dB at distances up to 2m provided that the microphone position is at least 0,5 away from ceiling and walls. Proposals for amendments of the relevant ISO-standards are given.

Download or read book Impulse Response Measurement Using Complementary Sequences written by Christopher Warren (Computer musician) and published by . This book was released on 2014 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although several methods have been proposed for impulse response measurement in acoustic spaces, there is no ideal one. Each responds differently to environmental noise present in the space being measured. Here a novel technique using complementary sequences is proposed, which offers improved accuracy over the commonly used methods under certain noise conditions. This method is compared with existing methods in the presence of several different noises, focusing on situations where the amplitudes of the noises are comparable to that of the measuring signal. Musical applications of the impulse responses generated by the new method are presented, focusing on their use in artificial reverberation. A library of impulse responses that have been created using this technique is discussed.

Download or read book Ultrasound Elastography for Biomedical Applications and Medicine written by Ivan Z. Nenadic and published by John Wiley & Sons. This book was released on 2018-10-25 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrasound Elastography for Biomedical Applications and Medicine Ivan Z. Nenadic, Matthew W. Urban, James F. Greenleaf, Mayo Clinic Ultrasound Research Laboratory, Mayo Clinic College of Medicine, USA Jean-Luc Gennisson, Miguel Bernal, Mickael Tanter, Institut Langevin – Ondes et Images, ESPCI ParisTech CNRS, France Covers all major developments and techniques of Ultrasound Elastography and biomedical applications The field of ultrasound elastography has developed various techniques with the potential to diagnose and track the progression of diseases such as breast and thyroid cancer, liver and kidney fibrosis, congestive heart failure, and atherosclerosis. Having emerged in the last decade, ultrasound elastography is a medical imaging modality that can noninvasively measure and map the elastic and viscous properties of soft tissues. Ultrasound Elastography for Biomedical Applications and Medicine covers the basic physics of ultrasound wave propagation and the interaction of ultrasound with various media. The book introduces tissue elastography, covers the history of the field, details the various methods that have been developed by research groups across the world, and describes its novel applications, particularly in shear wave elastography. Key features: Covers all major developments and techniques of ultrasound elastography and biomedical applications. Contributions from the pioneers of the field secure the most complete coverage of ultrasound elastography available. The book is essential reading for researchers and engineers working in ultrasound and elastography, as well as biomedical engineering students and those working in the field of biomechanics.