diff --git a/src/app.rs b/src/app.rs
index a517be8..23783e4 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -450,9 +450,19 @@ fn CallPanel(room: Memo<String>, me: String) -> impl IntoView {
 
         // Mirror the local MediaStream into the preview <video> element -
         // `srcObject` has no HTML attribute form, has to be set via JS.
+        //
+        // Also force `.muted` via the JS property here, not just the
+        // `muted` attribute on the element below: every video tile in this
+        // app is built client-side via `document.createElement` (never
+        // parsed from HTML), and browsers only seed the live `.muted`
+        // property from the `muted` *attribute* for parser-inserted
+        // elements. Without this, the local preview plays back the user's
+        // own mic through their speakers - audible as feedback in a
+        // solo call.
         Effect::new(move |_| {
             let stream = call_state.get_value().local_stream().get();
             if let Some(el) = local_video_ref.get() {
+                el.set_muted(true);
                 el.set_src_object(stream.as_ref());
             }
         });