Please "Mute your voice"!

Since in the current electronic age mute has come to mean to silence completely (not merely to soften, as in the technical musical direction con sordino), the actual meaning of the sentence you propose comes awfully close to STFU, so it perhaps depends on the strength of your jaw (to withstand the blows of your interlocutor’s fist). To speak plainly, the sentence you propose is likely to prove highly offensive. “Please lower your voice” is much safer for your jaw.

"Could you please lower your voice" sounds more appropriate.

Or you can rather say Please stop talking which sounds little disrespectful to me. But as we know context is more important than content so feel free to use any of these suggestion according to your situation.

In a face-to-face conversation, "mute your voice" would be awkward. But in the context of an online meeting, where people from different places join in over a common conferencing bridge, the speaker could politely request others to "go on mute" (to mute their mics for the time being) so as to avoid unnecessary noise over the bridge.