diff --git a/examples/client_browser.html b/examples/client_browser.html
index 508e31c..e24cb4e 100644
--- a/examples/client_browser.html
+++ b/examples/client_browser.html
@@ -115,7 +115,7 @@
       log(`Playing test tone at ${freq} Hz for ${duration}s`);
     };
 
-    const playPcm16 = async (base64Data) => {
+    const playPcm16 = async (base64Data, seq) => {
       await ensureAudioContext();
       if (audioCtx.state !== 'running') {
         throw new Error(`AudioContext not running (state=${audioCtx.state})`);
@@ -124,7 +124,11 @@
       if (raw.length === 0) {
         throw new Error('Empty audio data');
       }
-      const samples = new Int16Array(raw.length / 2);
+      if (raw.length % 2 !== 0) {
+        throw new Error(`Odd raw audio length: ${raw.length}`);
+      }
+      const sampleCount = raw.length / 2;
+      const samples = new Int16Array(sampleCount);
       const view = new DataView(samples.buffer);
       for (let i = 0; i < raw.length; i += 2) {
         // little-endian PCM16
@@ -132,9 +136,9 @@
       }
 
       // Convert to float32 AudioBuffer
-      const buffer = audioCtx.createBuffer(1, samples.length, 24000);
+      const buffer = audioCtx.createBuffer(1, sampleCount, 24000);
       const channel = buffer.getChannelData(0);
-      for (let i = 0; i < samples.length; i++) {
+      for (let i = 0; i < sampleCount; i++) {
         channel[i] = samples[i] / 32768.0;
       }
 
@@ -146,8 +150,14 @@
       if (nextStartTime < now) {
         nextStartTime = now;
       }
-      source.start(nextStartTime);
+      const startAt = nextStartTime;
+      source.start(startAt);
       nextStartTime += buffer.duration;
+      log(`audio queued seq=${seq} raw=${raw.length} samples=${sampleCount} duration=${buffer.duration.toFixed(2)}s startAt=${startAt.toFixed(3)} ctxState=${audioCtx.state}`);
+
+      source.onended = () => {
+        log(`audio ended seq=${seq}`);
+      };
     };
 
     $('connect').onclick = async () => {
@@ -180,12 +190,21 @@
         };
 
         ws.onmessage = (event) => {
-          const msg = JSON.parse(event.data);
+          let msg;
+          try {
+            msg = JSON.parse(event.data);
+          } catch (err) {
+            log(`malformed message: ${err.message}`);
+            return;
+          }
           if (msg.type === 'audio') {
             (async () => {
               try {
-                await playPcm16(msg.data);
-                log(`audio seq=${msg.seq} len=${(msg.data.length * 3 / 4 / 2 / 24000).toFixed(2)}s`);
+                log(`received audio seq=${msg.seq} base64=${String(msg.data).length} format=${msg.format} sr=${msg.sample_rate} ch=${msg.channels}`);
+                if (!msg.data || String(msg.data).trim() === '') {
+                  throw new Error('Server sent empty audio data');
+                }
+                await playPcm16(msg.data, msg.seq);
               } catch (err) {
                 log(`audio playback error: ${err.message}`);
               }
@@ -194,6 +213,8 @@
             log(`status ${msg.event} seq=${msg.seq}`);
           } else if (msg.type === 'error') {
             log(`error: ${msg.message}`);
+          } else {
+            log(`unknown message type=${msg.type}`);
           }
         };
 
@@ -222,7 +243,8 @@
         return;
       }
       await ensureAudioContext();
-      nextStartTime = 0;
+      nextStartTime = audioCtx.currentTime;
+      log(`Speak start, ctxState=${audioCtx.state}, nextStartTime=${nextStartTime.toFixed(3)}`);
 
       const text = $('text').value.trim();
       const words = text.split(/\s+/);