I posted this in another thread, but I figure this thread is probably more appropriate for this information, so I’m reposting it here again for reference.
For folks who don’t care to spend time browsing through the OPN materials from the link https://www.oticon.com/support/downloads/, I can summarize what I find below on the differences:
Balancing power effect: Opn1: 100%, Opn2 and 3: 50%
Max noise removal: Opn1: 9db, Opn2: 5 db, Opn3: 3db
Spatial Sound LX (sound localization): Opn1: 4 estimators, Opn2 and 3: 2 estimators
Clear Dynamics (expands the dynamic input range, processing sounds up to 113dB SPL, to preserve sound quality even at loud input levels -> provide better sound quality without distortion and artifact at loud input levels, while still keeping the sound quality of soft input levels intact): Opn1 and 2: yes, Opn3: no
Binaural noise management (optimizes listening in asymmetrical noisy situations): Opn1 and 2: yes, Opn3: no
Fitting bandwidth: Opn1: 10 KHz, Opn2 and 3: 8 KHz
Processing channels: Opn1: 64, Opn2 and 3: 48
Transient Noise Management (Protects against sudden loud sounds with fast recovery to preserve audibility): Opn1: 4 configurations, Opn2 and 3: On/Off
Personalization and Optimized Fitting:
YouMatic LX (Accommodates personal listening preferences and sound perceptions in the prescription of gain and automatics): Opn1: 3 configurations, Opn2: 2 configurations, Opn1: 1 configuration.
Fitting bands (for a precise fit and more fine-tuning options for client fittings): Opn1: 16, Opn2: 14, Opn3: 12