Abstract: A method of controlling noise from a six cylinder engine that can selectively use in separate operating modes either three cylinders, four cylinders, or all six cylinders, is provided that uses a noise cancellation system to provide a cancellation sound at a first frequency representative of the engine operating mode. When the vehicle changes, for example, from a three cylinder utilization mode to six cylinder utilization mode, the method extends the provision of the noise cancellation sound, at a frequency representative of three cylinder operation, beyond the time when three cylinder mode is changed to six cylinder mode. As a result, a residual “pop” noise associated with the vehicle exhaust, that is traditionally heard during the transition period is cancelled and no longer noticeable. The method also includes implementation of a waiting time before a providing cancellation sounds of different frequencies, to avoid amplitude mismatch.

Abstract: A method of controlling noise from a six cylinder engine that can selectively use in separate operating modes either three cylinders, four cylinders, or all six cylinders, is provided that uses a noise cancellation system to provide a cancellation sound at a first frequency representative of the engine operating mode. When the vehicle changes, for example, from a three cylinder utilization mode to six cylinder utilization mode, the method extends the provision of the noise cancellation sound, at a frequency representative of three cylinder operation, beyond the time when three cylinder mode is changed to six cylinder mode. As a result, a residual “pop” noise associated with the vehicle exhaust, that is traditionally heard during the transition period is cancelled and no longer noticeable. The method also includes implementation of a waiting time before a providing cancellation sounds of different frequencies, to avoid amplitude mismatch.