9SYNCHRONY, FSP and the SONNET/RONDO System

TThe rotatable MRI magnet

The SYNCHRONY / SYNCHRONY 2 implant carries a diametrically magnetised magnet in a housing that freely rotates to align with an external MRI field, reducing torque, pain and the need for magnet removal — making it MRI-conditional at high field strength without surgery, a major clinical differentiator (commonly 1.5 T and 3.0 T; verify exact conditions per variant; cross-ref Module 15).[2014]

CFine-structure coding

MED-EL's signature coding strategies are FSP and FS4/FS4-p, which encode temporal fine structure (zero-crossing timing) on the most apical low-frequency channels rather than envelope alone, aiming for better pitch, music and tonal-language perception; FS4 applies fine-structure timing to up to 4 apical channels, with HDCIS as the envelope-based comparator (cross-ref Ch.8). Riss et al. ran crossover studies of FSP/FS4/FS4-p.[2006]

TSONNET behind-the-ear

The behind-the-ear processor line is SONNET / SONNET 2 (with an EAS variant for combined electric-acoustic stimulation), used across the portfolio.[2014]

CRONDO single-unit

The RONDO / RONDO 2 / RONDO 3 is a single-unit, button-style processor worn off the ear over the implant magnet, integrating microphone, electronics, battery and coil in one piece — the original single-unit concept; RONDO 2 introduced wireless charging.

TThe Oticon/Neurelec lineage

Oticon Medical's CI line descends from Neurelec (formerly MXM), itself from Claude-Henri Chouard's pioneering French multichannel work (1976–77), marketing the Neuro Zti implant with Digisonic heritage as a smaller fourth manufacturer (cross-ref Ch.1 History). NOTE: Oticon Medical announced exit/transfer of its CI business (~2023, to Cochlear) — confirm current availability before teaching as available.