diff --git a/js/engine.js b/js/engine.js
index db98158..a96e953 100644
--- a/js/engine.js
+++ b/js/engine.js
@@ -283,6 +283,7 @@ function checkMilestones() {
                 G.milestones.push(m.flag);
                 log(m.msg, true);
                 showToast(m.msg, 'milestone', 5000);
+                if (typeof Sound !== 'undefined') Sound.playMilestone();
 
                 // Check phase advancement
                 if (m.at) {
@@ -296,6 +297,10 @@ function checkMilestones() {
                             if (pNum > _shownPhaseTransition) {
                                 _shownPhaseTransition = pNum;
                                 showPhaseTransition(pNum);
+                                if (typeof Sound !== 'undefined') {
+                                    Sound.playFanfare();
+                                    Sound.updateAmbientPhase(pNum);
+                                }
                             }
                         }
                     }
@@ -356,6 +361,7 @@ function buyBuilding(id) {
     log(`Built ${def.name} ${label} (total: ${totalBuilt})`);
     // Particle burst on purchase
     const btn = document.querySelector('[onclick="buyBuilding(\'' + id + '\')"]');
+    if (typeof Sound !== 'undefined') Sound.playBuild();
     if (btn) {
         const rect = btn.getBoundingClientRect();
         const cx = rect.left + rect.width / 2;
@@ -396,6 +402,7 @@ function buyProject(id) {
 
     updateRates();
     // Gold particle burst on project completion
+    if (typeof Sound !== 'undefined') Sound.playProject();
     const pBtn = document.querySelector('[onclick="buyProject(\'' + id + '\')"]');
     if (pBtn) {
         const rect = pBtn.getBoundingClientRect();
@@ -437,6 +444,7 @@ function renderDriftEnding() {
     // Fade-in animation
     el.classList.add('fade-in');
     el.classList.add('active');
+    if (typeof Sound !== 'undefined') Sound.playDriftEnding();
 
     // Log the ending text with delays for dramatic effect
     const lines = [
@@ -479,8 +487,7 @@ function renderBeaconEnding() {
         </button>
     `;
     document.body.appendChild(overlay);
-
-    // Create particle/light ray container
+    if (typeof Sound !== 'undefined') Sound.playBeaconEnding();
     const particleContainer = document.createElement('div');
     particleContainer.id = 'beacon-ending-particles';
     document.body.appendChild(particleContainer);
@@ -762,6 +769,7 @@ function writeCode() {
     }
     // Float a number at the click position
     showClickNumber(amount, comboMult);
+    if (typeof Sound !== 'undefined') Sound.playClick();
     updateRates();
     checkMilestones();
     render();
diff --git a/js/main.js b/js/main.js
index d5a3f17..d00dc43 100644
--- a/js/main.js
+++ b/js/main.js
@@ -42,6 +42,18 @@ window.addEventListener('load', function () {
     // Game loop at 10Hz (100ms tick)
     setInterval(tick, 100);
 
+    // Start ambient drone on first interaction
+    if (typeof Sound !== 'undefined') {
+        const startAmbientOnce = () => {
+            Sound.startAmbient();
+            Sound.updateAmbientPhase(G.phase);
+            document.removeEventListener('click', startAmbientOnce);
+            document.removeEventListener('keydown', startAmbientOnce);
+        };
+        document.addEventListener('click', startAmbientOnce);
+        document.addEventListener('keydown', startAmbientOnce);
+    }
+
     // Auto-save every 30 seconds
     setInterval(saveGame, CONFIG.AUTO_SAVE_INTERVAL);
 
@@ -69,6 +81,7 @@ function toggleMute() {
     }
     // Save preference
     try { localStorage.setItem('the-beacon-muted', _muted ? '1' : '0'); } catch(e) {}
+    if (typeof Sound !== 'undefined') Sound.onMuteChanged(_muted);
 }
 // Restore mute state on load
 try {