A variable-reluctance type vibrator for generating vibrations in a bone anchored hearing aid. The vibrator includes a vibrator plate and a bobbin base with a vibrator gap therebetween. The vibrator gap between the vibrator plate and the bobbin base, or some other spacing in the vibrator where a relative movement between two surfaces is generated during the vibratory function, is at least partially filled with a fluid or gel for providing the main part of the damping of the resonance frequency of the vibrator.

A coupling device for attaching the external hearing aid part to the skull bone anchored part in a bone conducting hearing aid apparatus. The retaining force in the coupling device is substantially established with a permanent magnet. The bone anchored part and the external hearing aid part include a magnetic part.