I am not an expert, just a guy who is curious and frugal. I have found mixed information on the similarities of signia and various truhearing offerings, I have a noahlink wireless 2, and the lastest connex , and the rexton version of connexx so I started experimenting.
Thinks I think I have confirmed.
Th5 premium are virutally the same as signia 7x. Truhearing is recognized by connexx, and the signia app.
TH6 premium are virtually the same as signia 7AX again recognized by connexx and app.
You can mix and match similar models.
TH7 premium is virtually the same as the Signia 7IX.
I tried to couple truhearing 6 premium to a signia 7ax. Initially connexx said they would not couple, but that there needed to be firmware updates. The firmware updated, then went into a firmware modification mode. When it was complete, I was able to program to my audiogram and insitu gram and have the app control and handle both the same as they would a matched pair.
Rexton is a different situation. Signia connexx recognizes rexton, but does not allow any changes to be made. Rexton connexx recognizes signia but similarly does not allow changes. Both ask for the other database to be added. I could not find a workaround to get rexton to play with signia in a mismatched pair.
Is anyone else curious about these things? Probably not, but I picked up several individual hearing aids up second hand to play around with and wanted to post my results.