reduction or cancellation of acoustic noise is achieved by providing an amplified , oppositely phased version of the noise by means of an acousto - fluidic amplifier . the amplified acoustic output noise is delivered through an impedance matching horn in destructively interfering relation with the original noise . depending on the acoustic noise source and its spatial distribution , the acousto - fluidic amplifier may be a single stage amplifier or multiple stages connected in parallel and / or cascade , with output horns spatially distributed to have the maximum cancellation effect . sensed noise , prior to fluidic amplification , may be processed in a manner to effect feedback or feedforward control of the amplified acoustic output signals .