diff --git a/client/index.html b/client/index.html
index b6f6e30..3cfd7fb 100644
--- a/client/index.html
+++ b/client/index.html
@@ -61,6 +61,7 @@
         <p><b>P:</b> Ping server</p>
         <p><b>M:</b> Mute/unmute</p>
         <p><b>Shift+M:</b> Toggle stereo/mono output</p>
+        <p><b>! (Shift+1):</b> Toggle loopback monitor</p>
         <p><b>E:</b> Cycle voice effect</p>
         <p><b>Dash or Equals:</b> Lower/raise active effect value</p>
       </div>
diff --git a/client/public/version.js b/client/public/version.js
index d3311c6..8113647 100644
--- a/client/public/version.js
+++ b/client/public/version.js
@@ -1,3 +1,3 @@
 // Maintainer-controlled web client version.
 // Format: YYYY.MM.DD Rn (example: 2026.02.20 R2)
-window.CHGRID_WEB_VERSION = "2026.02.20 R59";
+window.CHGRID_WEB_VERSION = "2026.02.20 R60";
diff --git a/client/src/audio/audioEngine.ts b/client/src/audio/audioEngine.ts
index 32a59be..07ded1d 100644
--- a/client/src/audio/audioEngine.ts
+++ b/client/src/audio/audioEngine.ts
@@ -38,6 +38,8 @@ export class AudioEngine {
   private outboundInputGain: GainNode | null = null;
   private outboundDestination: MediaStreamAudioDestinationNode | null = null;
   private outboundEffectRuntime: EffectRuntime | null = null;
+  private loopbackEnabled = false;
+  private loopbackRuntime: EffectRuntime | null = null;
   private outputMode: OutputMode = 'stereo';
   private effectIndex = EFFECT_SEQUENCE.findIndex((effect) => effect.id === 'off');
   private readonly effectValues: Record<EffectId, number> = {
@@ -160,6 +162,12 @@ export class AudioEngine {
     return this.outputMode;
   }
 
+  toggleLoopback(): boolean {
+    this.loopbackEnabled = !this.loopbackEnabled;
+    this.rebuildOutboundEffectGraph();
+    return this.loopbackEnabled;
+  }
+
   async attachRemoteStream(
     peer: SpatialPeerRuntime,
     stream: MediaStream,
@@ -321,6 +329,19 @@ export class AudioEngine {
       effect,
       this.effectValues[effect],
     );
+    this.rebuildLoopbackGraph(effect, this.effectValues[effect]);
+  }
+
+  private rebuildLoopbackGraph(effect: EffectId, effectValue: number): void {
+    if (!this.audioCtx || !this.outboundInputGain) {
+      return;
+    }
+    disconnectEffectRuntime(this.loopbackRuntime);
+    this.loopbackRuntime = null;
+    if (!this.loopbackEnabled) {
+      return;
+    }
+    this.loopbackRuntime = connectEffectChain(this.audioCtx, this.outboundInputGain, this.audioCtx.destination, effect, effectValue);
   }
 
   private clampLevel(value: number): number {
diff --git a/client/src/main.ts b/client/src/main.ts
index b0b3c97..9f16d37 100644
--- a/client/src/main.ts
+++ b/client/src/main.ts
@@ -988,6 +988,13 @@ function handleNormalModeInput(code: string, shiftKey: boolean): void {
     return;
   }
 
+  if (code === 'Digit1' && shiftKey) {
+    const enabled = audio.toggleLoopback();
+    updateStatus(enabled ? 'Loopback on.' : 'Loopback off.');
+    audio.sfxUiBlip();
+    return;
+  }
+
   if (code === 'KeyE') {
     const effect = audio.cycleOutboundEffect();
     updateStatus(effect.label);