Ericka can just bearly here a light pinging sound. Not loud, eyes those right next to her don't catch it. It takes a moment for her to realize it's her malumeter reacting to something. The akuma is within the range of it, but the raction seems like something is nearer, practically right in front of her another few steps, though she can't pinpoint where with this basic model malumeter.
Ericka, please make for me a Lore test, and a Spot test, the latter with advantage due to your malumeter