In the case of a hearing aid device which can be worn in the ear or a hearing
aid device with a otoplastic which can be worn in the ear, the penetration of direct
sound through a ventilation channel of the hearing aid device or of the otoplastic
is prevented. An acoustic signal is picked up from the ventilation channel via
a second microphone in a first region of the ventilation channel and phase-shifting
it in a filter device in such a way that the direct sound is at least largely eliminated
after the phase-shifted signal is emitted into the ventilation channel via a second
earphone. The invention offers the advantage that an enlargement of the cross section
of the ventilation channel is made possible as a result, even to provide an open
supply, without disturbing direct sound getting into the auditory canal of the
person wearing the hearing device.
