Interactions in the cochlea between air conduction and osseous and non-osseous bone conduction stimulation.

Since air-conducted (AC) and clinical (mastoid) bone-conducted (BC) sounds interact in the cochlea (e.g. pitch, cancellation, masking, beats), it has been thought that both AC and BC stimulations lead to a mechanical wave in the cochlea. However, there are also "non-osseous" forms of BC, i.e. auditory sensation produced when the clinical bone vibrator is applied to "non-osseous" soft tissue sites. In the present study, such "non-osseous" sites were identified (e.g. eye, cheek, neck) and they interacted with AC and osseous BC (pitch matching, beats, masking), indicating that all of these forms of auditory stimulation converge in the cochlea, producing the same pattern of mechanical activity, leading to their interactions.