Chrome allows users to mute tabs, simply by right-clicking them and hitting Mute Tab. What I'm wondering is if there's a way to detect when a user has muted the tab.
To clarify, I'm wondering if there's a way for a website to detect when I've muted their tab.
No, this is not possible in Google Chrome.
Such events can be recorded using low-level APIs exposed by Chrome for telemetry, but it cannot be done via any of the Web APIs available.