An apparatus for controlling sound of an engine comprises a sound sensor, an exhaust valve, and a controller. The controller is configured to determine a sound level of a peak sound frequency within a predetermined sound frequency range by use of output from the sound sensor, compare the sound level of the peak sound frequency to a predetermined sound level, and change the position of the exhaust valve based on the comparison between the sound level of the peak sound frequency and the predetermined sound level. An associated method is disclosed.