There is provided a speaker that uses a waterproof vibration plate that is
obtained by forming a water repellent layer containing wax on a surface
of paper pulp by the use of a wax-based emulsion in a suspension of the
paper pulp, then forming a binder layer containing rosin or alkyl ketene
dimmer on a surface of the water repellent layer by the use of a rosin
sizing agent or an alkyl ketene dimmer sizing agent in the suspension,
then forming an oil repellent layer containing a fluorinated resin on a
surface of the binder layer by the use of a fluorine-based resin emulsion
in the suspension, then forming the paper pulp into paper, and then
heating and drying the same.