Title: Most Efficient Practice of Nearfield Measurements Inside a Car for Improving Acoustic Comfort
text: A continuously growing demand comes from the automotive industry for optimization of materials and sound insulating products implementation inside the car, so as to propose the best acoustic performance at reduced costs. The acoustical holography system dBVISION developed by 01dB Acoustics & Vibration provides part of the solution to such a demand. Its demonstrated capability of measuring the acoustic field inside a vehicle makes it an advanced tool for performing extensive studies of the acoustic transparency of car openings as well as wind tunnel measurements. The developed technique allows now for: 1- Detailed localization of noise sources or acoustic weakness points inside the vehicle, 2- Knowledge of the acoustic energy distribution on elementary surfaces (such as doors, windscreen, roof, sealing system, etc.), 3- Reconstruction of the energy radiated by elementary surfaces in order to predict the acoustic pressure at the driver's and passengers' ears, 4- Estimation of the acoustic incidence of local modifications on components of the tested car. Technical background, together with the main features of this acoustical imaging system, will be exposed and the presentation will illustrate with practical examples how this fits to the project engineer process considering new acoustically driven design methods for a complete understanding and control of all components and systems involved in the car performance.