The paper considers the method of selecting the configuration of dissipative silencers with the required acoustic efficiency under the constraints imposed on their overall dimensions. The peculiarity of the considered approach consists in the use of an integral indicator of acoustic efficiency and a prototype silencer with dimensionless parameters. The studies were carried out by means of numerical calculations using the finite element method. The finite element model of the dissipative silencer used the acoustic characteristics of fibre sound-absorbing material obtained on the basis of experimental studies.