Going loud would not invoke the sanctity of merits in my opinion. As it states: "Her Primum is set to 10, with all the benefits that entails." For the merit, it states "add your dots in Resonance Aware to Primum for determining the range of her senses".

As there is nothing that states that you should use your "normal" Primum or "give up" (sanctity of merits) your dots, then I would say that it would work as written. So yes, for the duration of Going Loud, you would get the extra range.