A vibrator for a bone conduction type hearing aid device. The vibrator
includes a coil for generating a dynamic magnetic field and two permanent
magnets for generating a static magnetic field. The two permanent magnets
are working independently from each other in the magnetic circuit and an
arranged in such a way that the static and dynamic magnetic fields are
substantially separated from each other, but coinciding in the air gaps
formed between the coil and magnet arrangement and the casing, whereby
the vibrator provides an axial force.