8The MED-EL Philosophy: Long, Flexible, Lateral-Wall

TThe lateral-wall bet

Founded by Erwin and Ingeborg Hochmair in Innsbruck, MED-EL builds straight, non-pre-curved lateral-wall arrays that rest against the outer wall of scala tympani rather than hugging the modiolus, with the stated rationale of gentle atraumatic insertion and broad coverage of the full cochlear length — at the cost of greater required array length.[2012]

CThe flexible FLEX tip

The signature FLEX tip tapers toward the apex and arranges the most apical contacts as single (rather than paired) flexible contacts, so the apical few millimetres deflect around the rising basilar membrane instead of buckling or translocating into scala vestibuli (typically 5 single apical contacts; tip ~0.3–0.5 mm vs ~0.8 mm proximally).[2006]

TTwelve channels on 24 contacts

MED-EL uses a constant 12 stimulation channels carried on 24 physical contacts (paired) regardless of array length — uniquely decoupling channel count from array choice. This is the key teaching contrast with Cochlear (22 contacts) and Advanced Bionics (16 contacts): the surgeon picks length, not channel count.[2014]

CThe FLEX length ladder

The FLEX length ladder matches insertion depth to cochlear size and goal: FLEXSOFT/Standard (~31.5 mm) for full coverage; FLEX28 (~28 mm), FLEX26, FLEX24, FLEX20 (~20 mm) progressively shorter, the shortest for electric-acoustic stimulation and hearing preservation (the name's number approximates active length in mm).[2017]

TThe deepest insertion

The ~31.5 mm Standard/FLEXSOFT array enables the deepest commercial insertion, reaching well into the apical (second) turn (~630°, up to ~700–720°), placing electrodes at frequency places matching natural tonotopy to support fine-structure low-frequency coding — though Zeng notes effects of insertion beyond 20 mm remain partly uncertain.

CThe trade-off triangle

MED-EL is the cleanest counterpoint in the design trade-off triangle: long flexible lateral-wall = atraumatic + full coverage + apical fine-structure coding, at the cost of greater distance from the spiral ganglion (theoretically less focused, higher current) than perimodiolar arrays (cross-ref Module 9, Module 12).