A method of noise abatement within a signal stream containing unwanted signal referred to as noise comprising: acquiring a digitized noise signal based on a noise signal acquired by an input microphone (14,14a) from an environment in which the signal stream is present; using a digital processor circuit to subdivide the acquired noise signal into different frequency band segments and thereby generate a plurality of segmented noise signals; individually for each segmented noise signal, using the digital processor circuit to shift in time the segmented noise signal by an amount dependent on a selected frequency of the segmented noise signal, thereby producing a plurality of shifted segmented noise signals; combining the plurality of shifted segmented noise signals to form a composite anti-noise signal; and outputting the anti-noise signal into the signal stream to abate the noise through destructive interference; characterized in that the digital processor circuit is programmed to: measure and calculate a system offset time that takes into account both an in-air propagation time associated with the noise signal and a system propagation time associated with the throughput speed of the digital processor circuit and any associated equipment; and shift the phase of each segmented noise signal by an amount corresponding to a phase shift time calculated as one-half the inverse of the selected frequency and further adjusted by the system offset time; wherein the in-air propagation time is measured as the transit time for a signal to travel through air from the input microphone (14,14a) to a feedback microphone; and wherein the system propagation time is measured as the time delay attributed to the time taken for the acquired signal to be processed, output to a speaker system (24, 24a), and received at the feedback microphone. acquiring a digitized noise signal based on a noise signal acquired by an input microphone (14,14a) from an environment in which the signal stream is present; using a digital processor circuit to subdivide the acquired noise signal into different frequency band segments and thereby generate a plurality of segmented noise signals; individually for each segmented noise signal, using the digital processor circuit to shift in time the segmented noise signal by an amount dependent on a selected frequency of the segmented noise signal, thereby producing a plurality of shifted segmented noise signals; combining the plurality of shifted segmented noise signals to form a composite anti-noise signal; and outputting the anti-noise signal into the signal stream to abate the noise through destructive interference; characterized in that the digital processor circuit is programmed to: measure and calculate a system offset time that takes into account both an in-air propagation time associated with the noise signal and a system propagation time associated with the throughput speed of the digital processor circuit and any associated equipment; and shift the phase of each segmented noise signal by an amount corresponding to a phase shift time calculated as one-half the inverse of the selected frequency and further adjusted by the system offset time; wherein the in-air propagation time is measured as the transit time for a signal to travel through air from the input microphone (14,14a) to a feedback microphone; and wherein the system propagation time is measured as the time delay attributed to the time taken for the acquired signal to be processed, output to a speaker system (24, 24a), and received at the feedback microphone. measure and calculate a system offset time that takes into account both an in-air propagation time associated with the noise signal and a system propagation time associated with the throughput speed of the digital processor circuit and any associated equipment; and shift the phase of each segmented noise signal by an amount corresponding to a phase shift time calculated as one-half the inverse of the selected frequency and further adjusted by the system offset time; wherein the in-air propagation time is measured as the transit time for a signal to travel through air from the input microphone (14,14a) to a feedback microphone; and wherein the system propagation time is measured as the time delay attributed to the time taken for the acquired signal to be processed, output to a speaker system (24, 24a), and received at the feedback microphone.