An active noise reduction system (2) comprising an electroacoustic plasma transducer (5) for mounting in an installation structure and an acoustic sensing system (11). The electroacoustic plasma transducer comprises a plasma electrode arrangement (6) including a collector electrode (8) and a corona electrode (9), and a control system (7) connected to the plasma electrode arrangement for supplying power to the plasma electrode arrangement. The control system comprises a controller (12), and a amplification circuit (13). The acoustic sensing system is connected to the control system providing a measurement signal of an environmental sound to control the output of the electroacoustic transducer for reducing noise. The control system comprises a filter implementing a control transfer function θ(ω) based on a model of the electroacoustic plasma transducer.

A sound muffling chamber covers a nose and mouth in an airtight manner. The sound muffling chamber includes a microphone that detects vocal sound waves in the sound muffling chamber and generates a voice signal. A digital signal processing system analyzes the voice signal and generates a voice cancellation signal. A sound silencing chamber includes a speaker that generates out of phase sound waves in response to the voice cancellation signal that superimposes on and cancels the vocal sound waves. A sound decelerator is positioned between the sound muffling chamber and the sound silencing chamber and configured to increase a traveling time of the vocal sound waves such that the vocal sound waves' arrival at the sound silencing chamber may be synchronized with the arrival of a voice cancellation signal. The sound muffling chamber may include inflatable cells separated by slats such that the sound muffling chamber is foldable.