  The electroacoustic resonator is an effcient electro-active device for noise
attenuation in enclosed cavities or acoustic waveguides. It is made of a
loudspeaker (the actuator) and one or more microphones (the sensors). So far,
the desired acoustic behaviour, expressed in terms of a linear relationship
between sound pressure and vibrational motion, has been more efficiently
achieved by a model-inversion strategy which is implemented by driving the
electrical current in the loudspeaker coil, based upon the measured pressure.
The corrector transfer function is hence digitally executed by the classical
infinite-impulse response technique. In order to enforce non-linear, instead of
linear, operators between the pressure and vibrational motion of the speaker
diaphragm, in the same pressure-based, current-driven architecture, the
transfer-function-based control strategies must be abandoned. In this
manuscript, we present a novel technique based upon real-time integration of
potentially any target dynamics (either linear or nonlinear). Then, we
experimentally validate such control strategy by enforcing a Duffing type
dynamics at excitation levels far below the linearity limit of the
mechano-acoustical dynamics of the resonator. Such control strategy
demonstrates to efficiently reproduce nonlinear operators, opening the doors
for the experimental investigation of noise-control by a potentially vast
spectrum of programmable non-linear boundaries, under the ordinary sound
excitation levels.
