diff --git a/packages/services/voice-service/src/api/test_tts.py b/packages/services/voice-service/src/api/test_tts.py
index bcfa230..7be1974 100644
--- a/packages/services/voice-service/src/api/test_tts.py
+++ b/packages/services/voice-service/src/api/test_tts.py
@@ -366,7 +366,7 @@ async def tts_synthesize_openai(
     model: str = Query("tts-1", regex="^(tts-1|tts-1-hd|gpt-4o-mini-tts)$"),
     voice: str = Query("alloy", regex="^(alloy|ash|ballad|coral|echo|fable|nova|onyx|sage|shimmer)$"),
 ):
-    """Synthesize text to audio via OpenAI TTS API."""
+    """Synthesize text to audio via OpenAI TTS API, resampled to 16kHz WAV."""
     client = _get_openai_client()
     if client is None:
         return Response(content="OPENAI_API_KEY not configured", status_code=503)
@@ -377,9 +377,16 @@ async def tts_synthesize_openai(
             model=model,
             voice=voice,
             input=text,
-            response_format="wav",
+            response_format="pcm",  # raw 24kHz 16-bit mono PCM (no header)
         )
-        return response.content
+        raw_pcm = response.content
+        # Resample 24kHz → 16kHz to match Flutter player expectations
+        audio_np = np.frombuffer(raw_pcm, dtype=np.int16).astype(np.float32)
+        target_len = int(len(audio_np) / 24000 * 16000)
+        indices = np.linspace(0, len(audio_np) - 1, target_len)
+        resampled = np.interp(indices, np.arange(len(audio_np)), audio_np)
+        pcm_16k = resampled.clip(-32768, 32767).astype(np.int16).tobytes()
+        return _make_wav(pcm_16k, 16000)
 
     try:
         wav_bytes = await loop.run_in_executor(None, _synth)