At the end of the first century, when dotaku grew in size, the crown was changed to something more decorative and thinner, which possibly means the purpose was changed from "hearing" a sound to "exhibiting" them on the ground or floors of shrines (there is another theory described as below, though).
1世紀末頃には大型化が進み、鈕が薄手の装飾的な物への変化が見られることから、（後述のように異論はあるが、）音を出して「聞く」目的から地面か祭殿の床に置かれて「見せる」目的へと変化したのではないかと言われている。