Science - Which material is best in preventing sound

During our Science lesson today, we investigated which material was best in preventing sound from being heard. We wrapped a shaker in a variety of materials (paper towel, paper, clingfilm, fabric, foil) and recorded the sound. We played the recordings and then we then made a judgement as to which material was the best in preventing the sound from being heard. We found that the fabric was the best form of soundproofing as when shook, we could hardly hear the shaker at all.