The problems of designing helicopters with regard to the requirements for cabin noise

High noise levels in helicopter cabins are currently an important problem in solving environmental problems in civil aviation. The published data indicate high noise levels in the cabins of operated helicopters of the order of 93-97.4 dBA, while noise levels of less than 80 dBA are safe for humans. In order to significantly reduce noise levels in helicopter cabins and ensure the required level of acoustic comfort for passengers, an integrated approach is proposed, consisting in the use of sound insulation and vibration damping materials in the on-board structure, as well as sound-absorbing structures configured to work effectively in the problematic frequency range of the helicopter passenger cabin.