diff --git a/plugins/platforms/matrix/adapter.py b/plugins/platforms/matrix/adapter.py
index fe3b82f701..1966110b00 100644
--- a/plugins/platforms/matrix/adapter.py
+++ b/plugins/platforms/matrix/adapter.py
@@ -1603,9 +1603,16 @@ class MatrixAdapter(BasePlatformAdapter):
 
     async def send_voice(
         self, chat_id: str, audio_path: str, caption: Optional[str] = None, reply_to: Optional[str] = None,
-        metadata: Optional[Dict[str, Any]] = None) -> SendResult:
-        """Upload audio as an MSC3245 voice message. Voice bubbles need Ogg/Opus but callers pass any
-        format (e.g. TTS output), so transcode here — best-effort: without ffmpeg the original is sent."""
+        metadata: Optional[Dict[str, Any]] = None, is_voice: Optional[bool] = None) -> SendResult:
+        """Upload audio. The base media dispatch calls this with ``is_voice``: True for a voice-tagged
+        attachment → MSC3245 voice bubble; False for an audio-ext MEDIA attachment → plain ``m.audio``
+        in the original format. Voice bubbles need Ogg/Opus but callers pass any format (e.g. TTS
+        output), so transcode there — best-effort: without ffmpeg the original is sent. Callers that
+        don't pass the flag (``play_audio``) keep the voice-bubble behavior this method was written
+        for (#116776: the dispatch always passes ``is_voice``, and rejecting it dropped the file)."""
+        if is_voice is False:
+            return await self._send_local_file(
+                chat_id, audio_path, "m.audio", caption, reply_to, metadata=metadata, is_voice=False)
         converted_path: Optional[str] = None
         if not str(audio_path).lower().endswith((".ogg", ".oga", ".opus")):
             # 48k (not the 32k default): Element renders voice bubbles at a higher quality tier.
diff --git a/tests/gateway/test_matrix_send_voice_dispatch.py b/tests/gateway/test_matrix_send_voice_dispatch.py
new file mode 100644
index 0000000000..1f6a6a38da
--- /dev/null
+++ b/tests/gateway/test_matrix_send_voice_dispatch.py
@@ -0,0 +1,86 @@
+"""Regression tests for Matrix ``send_voice`` dispatch compatibility (#116776).
+
+The base media dispatch calls ``send_voice(..., is_voice=...)`` for every audio
+MEDIA attachment. The Matrix adapter used to reject that kwarg, so all non-image
+MEDIA delivery raised ``TypeError: MatrixAdapter.send_voice() got an unexpected
+keyword argument 'is_voice'`` and the attachment was silently dropped.
+"""
+import asyncio
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from gateway.config import PlatformConfig
+
+
+def _make_adapter(**extra):
+    from plugins.platforms.matrix.adapter import MatrixAdapter
+
+    config = PlatformConfig(
+        enabled=True,
+        token="syt_test_token",
+        extra={
+            "homeserver": "https://matrix.example.org",
+            "user_id": "@bot:example.org",
+            **extra,
+        },
+    )
+    return MatrixAdapter(config)
+
+
+def _spy_send_local_file(adapter):
+    adapter._send_local_file = AsyncMock(return_value=MagicMock(success=True))
+    return adapter._send_local_file
+
+
+def test_dispatch_call_with_is_voice_false_sends_plain_audio():
+    """The exact dispatcher call shape (base.py ``_send_one``) must not raise
+    TypeError, and an audio-ext attachment must keep its original format."""
+    adapter = _make_adapter()
+    spy = _spy_send_local_file(adapter)
+
+    result = asyncio.run(adapter.send_voice(
+        chat_id="!room:example.org", audio_path="/tmp/clip.mp3", metadata=None, is_voice=False))
+
+    assert result.success is True
+    spy.assert_awaited_once()
+    args, kwargs = spy.call_args
+    assert args[0] == "!room:example.org"
+    assert args[1] == "/tmp/clip.mp3"  # original file, no transcode
+    assert args[2] == "m.audio"
+    assert kwargs["is_voice"] is False
+
+
+def test_voice_tagged_attachment_gets_voice_bubble():
+    adapter = _make_adapter()
+    spy = _spy_send_local_file(adapter)
+
+    asyncio.run(adapter.send_voice(
+        chat_id="!room:example.org", audio_path="/tmp/clip.ogg", metadata=None, is_voice=True))
+
+    args, kwargs = spy.call_args
+    assert args[1] == "/tmp/clip.ogg"
+    assert kwargs["is_voice"] is True  # MSC3245 voice metadata path
+
+
+def test_legacy_caller_without_flag_keeps_voice_bubble():
+    """``play_audio`` (base default) calls send_voice without the flag; TTS
+    playback must stay a voice bubble."""
+    adapter = _make_adapter()
+    spy = _spy_send_local_file(adapter)
+
+    asyncio.run(adapter.send_voice(chat_id="!room:example.org", audio_path="/tmp/tts.ogg"))
+
+    args, kwargs = spy.call_args
+    assert kwargs["is_voice"] is True
+
+
+def test_voice_bubble_transcodes_non_ogg():
+    adapter = _make_adapter()
+    spy = _spy_send_local_file(adapter)
+    with patch("plugins.platforms.matrix.adapter.transcode_to_ogg_opus",
+               MagicMock(return_value="/tmp/clip_converted.ogg")):
+        asyncio.run(adapter.send_voice(
+            chat_id="!room:example.org", audio_path="/tmp/clip.mp3", is_voice=True))
+
+    args, kwargs = spy.call_args
+    assert args[1] == "/tmp/clip_converted.ogg"
+    assert kwargs["file_name"] == "clip.ogg"  # keep the caller's basename