Measures how long the sound actually stops when a stream drops. Add one engine per URL, then cut the network (DevTools → Network → Offline, or toggle Wi-Fi) and read the gap durations. Silence is detected on the decoded output, so it counts what you would hear, not what the network did. Point two engines at the same station over different transports (the HLS and Icecast presets below are both FIP) to compare them under the same outage.