A road noise-cancellation system, comprising: an actuator adapted to be disposed in a vehicle cabin; an error sensor, wherein the error sensor is a microphone adapted to be disposed within the vehicle cabin; a noise sensor, wherein the noise sensor is an accelerometer adapted to be mounted to and configured to detect vibrations transmitted through a vehicle structure; and a controller comprising a processor and a non-volatile memory, the controller being configured to store in the non-volatile memory a last-state of coefficients of a noise-cancellation filter, the controller being programmed to: generate a noise-cancellation signal with the noise-cancellation filter including a first plurality of coefficients, the noise-cancellation signal being based on the first plurality of coefficients, the noise-cancellation signal being transduced by the actuator to generate a noise-cancellation audio signal based on the noise-cancellation signal, the noise-cancellation audio signal destructively interfering with an undesired noise in a noise-cancellation zone; adjust the first plurality of coefficients of the noise-cancellation filter based on one or more input signals to provide a second plurality of coefficients, wherein the one or more input signals are a noise sensor signal from the noise sensor and an error sensor signal from the error sensor; store (306;308) the second plurality of coefficients in the non-volatile memory, as the last-state of coefficients of the noise-cancellation filter, at the end of an interval, wherein the length of the interval is determined according to the road conditions; and restore the second plurality of coefficients from the non-volatile memory to the noise-cancellation filter after determining that a third plurality of coefficients, provided by a second adjustment, are divergent or unstable. an actuator adapted to be disposed in a vehicle cabin; an error sensor, wherein the error sensor is a microphone adapted to be disposed within the vehicle cabin; a noise sensor, wherein the noise sensor is an accelerometer adapted to be mounted to and configured to detect vibrations transmitted through a vehicle structure; and a controller comprising a processor and a non-volatile memory, the controller being configured to store in the non-volatile memory a last-state of coefficients of a noise-cancellation filter, the controller being programmed to: generate a noise-cancellation signal with the noise-cancellation filter including a first plurality of coefficients, the noise-cancellation signal being based on the first plurality of coefficients, the noise-cancellation signal being transduced by the actuator to generate a noise-cancellation audio signal based on the noise-cancellation signal, the noise-cancellation audio signal destructively interfering with an undesired noise in a noise-cancellation zone; adjust the first plurality of coefficients of the noise-cancellation filter based on one or more input signals to provide a second plurality of coefficients, wherein the one or more input signals are a noise sensor signal from the noise sensor and an error sensor signal from the error sensor; store (306;308) the second plurality of coefficients in the non-volatile memory, as the last-state of coefficients of the noise-cancellation filter, at the end of an interval, wherein the length of the interval is determined according to the road conditions; and restore the second plurality of coefficients from the non-volatile memory to the noise-cancellation filter after determining that a third plurality of coefficients, provided by a second adjustment, are divergent or unstable. generate a noise-cancellation signal with the noise-cancellation filter including a first plurality of coefficients, the noise-cancellation signal being based on the first plurality of coefficients, the noise-cancellation signal being transduced by the actuator to generate a noise-cancellation audio signal based on the noise-cancellation signal, the noise-cancellation audio signal destructively interfering with an undesired noise in a noise-cancellation zone; adjust the first plurality of coefficients of the noise-cancellation filter based on one or more input signals to provide a second plurality of coefficients, wherein the one or more input signals are a noise sensor signal from the noise sensor and an error sensor signal from the error sensor; store (306;308) the second plurality of coefficients in the non-volatile memory, as the last-state of coefficients of the noise-cancellation filter, at the end of an interval, wherein the length of the interval is determined according to the road conditions; and restore the second plurality of coefficients from the non-volatile memory to the noise-cancellation filter after determining that a third plurality of coefficients, provided by a second adjustment, are divergent or unstable.