2.2 Setting
The experiment was conducted in a sound-attenuated audiometric booth
where three loudspeakers were positioned 1 m from the centre of the
subject’s head, at angles of -90° azimuth (left), 0° azimuth (front),
and +90° azimuth (right) on the horizontal plane. All patients were
fitted with a BCD (ADHEAR, MED-EL, Innsbruck, Austria) that was
uniformly programmed with omnidirectional microphone settings. ADHEAR
can be worn with an adhesive adapter or headband. For SSD, sufficient
transmission of bone conduction (BC) sound should be ensured to
stimulate the contralateral cochlea; the headband was chosen in this
study [9,10]. The volume setting of the BCD was set to the patient’s
preference, with the optimal level not changing during all experiments.