A thin hearing tube is to be fastened in a hearing apparatus such that it can be easily exchanged again. To this end, the end of the sound tube is melted, so that its diameter is enlarged. The sound tube can then be drawn into the bore, the inner diameter of which is smaller than the enlarged outer diameter of the end of the sound tube, until the extended end of the sound tube rests closely against one side of the bore. By cutting the sound tube end or by cutting through the tube at another point, it can be removed from the bore without any problem, so that a new tube can be fastened there.