The annual Open Seminar on Acoustics is the largest conference in Poland gathering leading Polish acoustics for over sixty years. It is organized cyclically by subsequent divisions of the Polish Acoustic Society - in 2020 by the Cracow Division. The Conference presents works from all fields of acoustics. The aim of the conference is to exchange scientific experience in the field of acoustics, promote science and integrate specialists from various fields related to acoustics. The Conference plays an integrating role for the environment of Polish acoustics as well as more and more often foreign ones. This enables the exchange of ideas, implementation of new research techniques and opening of new application areas.