An analytical mode has been de loped to study the potential of active noise control techniques for Ie reducing radiated tonal inlet noise from turbofan engines. The analytical model consists of multiple control sources placed in the periphery of the engine inlet duct which inject antinoise into the duct to destructively interfere with the tonal sound field generated by the fan. The development of the analytical expressions of the radiated sound fields due to both the disturbance and the control