Abstract: A vocalization assistance device includes: a mounting body that is mounted in an oral cavity of a person and that has a facing portion facing a palate of the person; a diaphragm that is provided at the facing portion and that is capable of outputting a sound recorded by a device having a recording function, as an original sound; and a passage that is provided at the facing portion and that is configured to transmit the original sound output from the diaphragm to a rear side of the oral cavity.

Abstract: The present invention is a method for producing a modified cellulose including the following step A: step A: introducing a cellulose raw material with a substituent having 6 or more carbon atoms to a group in which a hydrogen atom is removed from a hydroxyl group of a cellulose backbone, in the presence of water and a surfactant. The present invention relates to a method for producing a modified cellulose having a high affinity of an organic solvent, a resin or the like, and a hydrophobic medium, using a reaction system with low environmental loads and with prospects of reduction in production costs.

Abstract: The present invention relates to a method for producing modified cellulose fibers having cellulose I crystal structure, comprising: step A: introducing Substituent Group A to cellulose fibers via an ether bond in a solvent comprising water in the presence of a base, and step B: introducing Substituent Group B to cellulose fibers via an ether bond in a solvent comprising water in the presence of a base, wherein the method includes the steps A and B concurrently, or in the order of the step A and then the step B. The cellulose fibers of the present invention obtained by the method for production of the present invention have favorable dispersibility in a hydrophobic medium and a controlled increase in viscosity.