Multi-storey wooden buildings become more and more popular. As the new housing solutions are more accessible, acoustical inconveniences of wooden buildings become actual as never before. Wood, thanks to its high stiffness and low mass, allows to erect buildings at impressive pace, albeit cannot damp low frequency noises efficiently. This thesis is a part of the AkuTimber project run at Luleå University of Technology and partially covers one of the aspects considered within that project – attenuation of flexural wave in cross-laminated timber (CLT) at low frequencies by using a damping layer. In this thesis modal parameters of 3 different cases were taken into account – bare CLT panel, and 2 CLT panels with constrained layers – high density viscoelastic material and polyethene foil. The CLT panels were subjected to modal analysis with focus on bending modes below 50 Hz. Results were analyzed to observe the ability of the structures to attenuate flexural waves. / AkuTimber