1. ShapeLength (mm) Width @ base Cochle- ostomy Round window Nucleus Straight 22+10 (K) Contour Advance Slim straight (422) Split array SPSSSPSS 17 18 20-25 8 (x2) 0.6 0.8 0.6 + x2 ext + MedEl Standard / FlexSoft Flex series FORM series Compressed SSSSSSSS 31.5 20-28 19-24 15 1.3 0.8 0.8-1.9 0.7 ++++++++ ++++++++ Advanced Bionics 1J Helix Mid-scala PPPPPP 25 21 19 0.8 1.1 0.7 ++++++ ext +

2. Electrode Selection Options Pre-curved Banded Short Long Double or split Indications general use, atraumatic incomplete partition hearing preservation apical stimulation ossified cochleae

3. Normal cochlea “full” length peri-modiolar apical Electrode Selection

4. Labyrinthitis ossificans partial insertion compressed array double array

5. Electrode Selection Abnormal cochlea (incomplete partition) not pre-curved banded electrodes

6. Electrode Selection Hearing preservation Thin, flexible “atraumatic” electrodes Short or long Mid-scala

7. Electrode Selection Increasing choice Different manufacturers Which gives best speech discrimination? Which is best for hearing preservation? Which is easier / safer to re-implant?