Helicopter interior noise levels are recognized to be a source of discomfort for crew and passengers, being higher than those in turboprop or jet commercial aircrafts. A previous study^1 on comfort indicators for interior noise in helicopters concluded that sharpness and tonalness of the spectrum together account for 40% of the discomfort sensation behind loudness (57%). Transmission noise generated by the main gearbox (MGB) and composed of several tones at gear meshing frequency has a strong contribution to these indicators. It is also one of the main contributor to noise level in dB(A), which is assessed by European regulations on safety and health at work. Reduction of MGB noise levels by passive and active means have therefore been investigated widely. Active solutions have included structural control of roof panel^2,3, transmission beams4 or gearbox struts^5,6. In this paper, we are addressing another strategy, which is the active reduction of the gearbox noise by local active noise control in the headrest. Not only this solution has been identified has a potential solution for addressing tonal noise^7, but also for reducing noise from other sources at passenger’s ear (e.g. aerodynamic noise) without the need for a physical control architecture at each noise source or transmission paths.