Unified Strategy for Active Control of Air Induction Sound

For control of airborne sound, active control methods have found limited use, mainly due to technological impediments and lack of a compelling value proposition. This paper proposes a unified strategy with three key elements, optimal transducer output, integration of electronics and several evolutions focused on automotive air induction for optimal sound quality. To maintain signal accuracy, parameters such as response time, phase-matching, environment changes and source coupling are closely controlled. Some configurations for acoustic transducers are illustrated for achieving high output, dynamic range and suppression of background noise. Finally, the active system is augmented with many passive design features.