TUM Library

A virtual sound barrier is an active noise control system that uses arrays of loudspeakers and microphones to create a useful size of quiet zone and can be used to reduce sound propagation, radiation, or transmission from noise sources or to reduce noise level around people in a noisy environment. This book introduces the history, principle, and design methods of virtual sound barriers first, and then describes recent progress in research on the systems. Two virtual sound barrier systems, i.e., planar virtual sound barrier system and three-dimensional virtual sound barrier system, are discussed including applications, limitations and future direction discussions.

Cover; Half Title; Title Page; Copyright Page; Contents; Preface; Author; 1: Introduction; 1.1 Sound Propagation; 1.1.1 Sound Absorption and Absorption Coefficient; 1.1.2 Sound Insulation and Transmission Loss; 1.1.3 Sound Scattering and Scattering Coefficient; 1.1.4 Sound Diffraction and Insertion Loss; 1.2 Passive Sound Barriers; 1.2.1 The MacDonald Solution; 1.2.2 The Zhao Solution; 1.2.3 The Kurze and Anderson Formula; 1.3 Active Sound Barriers; 1.3.1 Principle; 1.3.2 Secondary Sources for Active Sound Barriers; 1.3.3 Sensing Strategies for Active Sound Barriers

1.3.4 Implementation Issues1.4 Virtual Sound Barriers; 1.4.1 History; 1.4.2 Principle; 1.4.3 Design Methods; 1.4.3.1 The Expansion Method of the Primary Sound Field; 1.4.3.2 The Least Mean Square Method; 2: Planar Virtual Sound Barriers; 2.1 Problem Description; 2.2 Control of Sound Propagation in Free Fields; 2.2.1 Control of the Plane Wave Primary Sound Field; 2.2.2 Control of the Primary Sound Field Generated by Monopole Sources; 2.2.3 Control of General Primary Sound Fields; 2.3 Control of Sound Propagation Through a Finite Size Aperture

2.3.1 Primary Sound Field with a Finite Size Aperture2.3.2 Control of Sound Propagation Through a Finite Size Aperture; 2.3.3 The Upper-Limit Frequency; 2.4 Control of Sound Radiation from an Opening of an Enclosure; 2.4.1 Sound Radiation from an Opening of an Enclosure; 2.4.2 Surface Control; 2.4.3 Boundary Control; 2.4.4 The Upper-Limit Frequency; 2.5 Control of Sound Transmission via an Opening into an Enclosure; 2.5.1 Sound Transmission via an Opening into an Enclosure; 2.5.2 Control with Planar Virtual Sound Barriers; 2.5.3 The Upper-Limit Frequency

3: Three-Dimensional Virtual Sound Barriers3.1 Problem Description; 3.2 Creation of a Quiet Zone in a Noisy Environment; 3.2.1 Formulation; 3.2.2 Two-Dimensional Simulations; 3.2.3 Three-Dimensional Simulations; 3.2.4 The 2.5-Dimensional Simulations; 3.2.5 Experiments; 3.2.6 Remarks; 3.3 Performance with a Diffracting Sphere Inside the Quiet Zone; 3.3.1 Formulation; 3.3.2 Simulations and Experiments; 3.3.3 Performance with a Moving Sphere; 3.4 Performance near a Reflective Surface; 3.4.1 Formulation; 3.4.2 Performance near a Reflective Surface

3.4.3 A Hybrid Virtual Sound Barrier near a Surface3.5 Error-Sensing Strategies; 3.5.1 Formulation; 3.5.2 Simulations; 3.5.3 A General Cost Function; 3.6 Virtual Error Sensors; 3.6.1 Formulation; 3.6.2 Simulations; 3.6.3 Remarks; 4: Applications; 4.1 Noise Radiation Control from Power Transformers in a Hemi-Closed Space; 4.2 Sound Transmission Control through an Open Window into a Room; 4.3 Implementation Issues; 5: Summary and Perspectives; 5.1 Summary; 5.2 Perspectives; 5.2.1 Future Research Topics; 5.2.2 Challenges for the Applications; References; Index

OCLC-licensed vendor bibliographic record.