Apparatus and method for reducing noise in a space due to a noisy system by electronic noise cancellation

An apparatus for reducing noise generated by a noisy system and propagated through ambient air as noise waves, wherein the noisy system comprises one or more noise sources, wherein the apparatus comprises:

• a) at least one microphone configured to receive noise from the noisy system and to generate noise electric signals,
• b) at least one loudspeaker configured to receive acoustic electric signals and consequently to emit acoustic waves toward said space, and
• c) a noise processor having at least one input and at least one output, wherein the at least one input is electrically coupled to the at least one microphone, the at least one output being electrically coupled to the at least one loudspeaker;
• wherein the apparatus is configured to reduce noise in a space,
• said space being predetermined, limited and at a first distance from the noisy system;
• wherein the at least one microphone is configured to be positioned at a second distance from the noisy system, and the at least one loudspeaker is configured to be positioned at a third distance from said space;
• and
• wherein the noise processor is configured to generate the acoustic electric signals by processing the noise electric signals so that noise waves coming from the noisy system and the acoustic waves coming from the at least one loudspeaker combine and cancel at said space;
• wherein the at least one loudspeaker is positioned at a fourth distance from the at least one microphone, wherein the noise processor is configured so that a processing time of the noise electric signals is smaller than or equal to said fourth distance divided by a sound waves propagation speed in air and a delay time is provided in said apparatus, wherein a sum of said processing time and said delay time is equal to said fourth distance divided by a sound waves propagation speed in air.