You're confusing the trials. The first link you posted was neither TENT-A1 (326 patients) or TENT-A2 (192 patients). That was a small pilot study done just before the original MuteButton was launched.
There were 3 arms in TENT-A1 (326 patients) that was divided 80% being trialled in Ireland and 20% in Germany. This study has been completed and is in the process of being peer reviewed. We have yet to see the papers.
The TENT-A2 study (192 patients) is still ongoing and should finish the 12 month follow up soon. This study has 4 arms divided by 80:80:16:16.
Here is a link to the recruitment of the study
https://clinicaltrials.gov/ct2/show/NCT03530306
What I found curious is that part of the inclusion criteria for the TENT-A2 is 'tonal' tinnitus, yet Dr. Ross O'Neill stated the tonality/intonality doesn't matter. But atonal tinnitus is not part of the exclusion criteria. However the PI can exclude patients on any other grounds they seem appropriate. This concerns me when studies are made by the developers of the device; how do we know they want to get in as many people with tonal tinnitus and not specifically exclude atonal; just to sell more devices?
Also
@Agrajag364, I don't know what these 4 arms consist of or why; but I presume they are confirming the results of the TENT-A1 study and the smaller arms (16) confirming they are the least effective maybe.