Open cells structure tannin–furanic foams prepared using two different types of tannins have been shown to give good sound absorption/acoustic insulation characteristics at medium and high frequencies (1000–4000Hz) with coefficients of acoustic absorption of 0.85–0.97. Their acoustic absorption coefficient was lower 0.40–0.60 at lower frequencies (250–500Hz). Compared with commercial foams, tannin–furanic foams have the same typical behavior of light porous materials. The more open-cell is the material the better is its sound absorption. Thicker samples absorb better at medium frequencies for all types of porous material tested.