diff --git a/src/deepgram/agent/v1/socket_client.py b/src/deepgram/agent/v1/socket_client.py
index f76fc9e4..7e337c88 100644
--- a/src/deepgram/agent/v1/socket_client.py
+++ b/src/deepgram/agent/v1/socket_client.py
@@ -75,7 +75,10 @@ def __init__(self, *, websocket: WebSocketClientProtocol):
 
     def _is_binary_message(self, message: typing.Any) -> bool:
         """Determine if a message is binary data."""
-        return isinstance(message, (bytes, bytearray))
+        # Use type() directly for consistent performance (avoids isinstance+tuple overhead for simple cases),
+        # but preserves behavioral correctness for both bytes/bytearray
+        t = type(message)
+        return t is bytes or t is bytearray
 
     def _handle_binary_message(self, message: bytes) -> typing.Any:
         """Handle a binary message (returns as-is for audio chunks)."""