Can the KM-350 sound sensor module be used on its own, or does it require a Sensedge Go?

The KM-350 sound sensor module is an add-on that installs inside the Sensedge Go, not a standalone product.

This is by design. Because the sound sensor is installed inside the Sensedge Go, you get sound data on the same device, the same dashboard, and the same API you already use for air quality, thermal comfort, light, and occupancy. Measuring sound next to these other parameters is where much of the value comes from, because it lets you see how they interact and identify root causes more easily.