The presented work investigates the tone noise of three booster stages designed for a high bypass ratio turbofan. Calculations were performed at the approach operational conditions. The frequency domain numerical method of multistage turbomachines tone noise simulation, developed in CIAM (Central Institute of Aviation Motors) and implemented in 3DAS (3 Dimensional Acoustics Solver) in-house solver was used. The aim was to perform once again the validation of the computational method and to obtain better understanding of the mechanisms of tone noise generation in multistage turbomachines. The results of the investigation were compared with the experimental data obtained in the CIAM C-3A acoustic test facility. In general satisfactory correspondence between the numerical calculations and the experiment was observed. This can be treated as a significant argument for the validity of the frequency domain method of the multistage turbomachinery tone noise calculations.