diff --git a/src/agents/realtime/openai_realtime.py b/src/agents/realtime/openai_realtime.py
index e03d56f4b..695d91c82 100644
--- a/src/agents/realtime/openai_realtime.py
+++ b/src/agents/realtime/openai_realtime.py
@@ -138,6 +138,7 @@ def __init__(self) -> None:
         self._ongoing_response: bool = False
         self._current_audio_content_index: int | None = None
         self._tracing_config: RealtimeModelTracingConfig | Literal["auto"] | None = None
+        self._created_session: OpenAISessionObject | None = None
 
     async def connect(self, options: RealtimeModelConfig) -> None:
         """Establish a connection to the model and keep it alive."""
@@ -298,10 +299,18 @@ async def _send_interrupt(self, event: RealtimeModelSendInterrupt) -> None:
         if not self._current_item_id or not self._audio_start_time:
             return
 
-        await self._cancel_response()
+        automatic_response_cancellation_enabled = (
+            self._created_session
+            and self._created_session.turn_detection
+            and self._created_session.turn_detection.interrupt_response
+        )
+
+        if not automatic_response_cancellation_enabled:
+            await self._cancel_response()
 
         elapsed_time_ms = (datetime.now() - self._audio_start_time).total_seconds() * 1000
-        if elapsed_time_ms > 0 and elapsed_time_ms < self._audio_length_ms:
+
+        if elapsed_time_ms > 0 and elapsed_time_ms <= self._audio_length_ms:
             await self._emit_event(RealtimeModelAudioInterruptedEvent())
             converted = _ConversionHelper.convert_interrupt(
                 self._current_item_id,
@@ -335,8 +344,16 @@ async def _handle_audio_delta(self, parsed: ResponseAudioDeltaEvent) -> None:
         )
 
     def _calculate_audio_length_ms(self, audio_bytes: bytes) -> float:
-        """Calculate audio length in milliseconds for 24KHz PCM16LE format."""
-        return len(audio_bytes) / 24 / 2
+        audio_format = "pcm16"
+        if self._created_session and self._created_session.output_audio_format:
+            audio_format = self._created_session.output_audio_format
+
+        if audio_format.startswith("g711"):
+            # 8kHz * 1 byte per sample
+            return (len(audio_bytes) / 8000) * 1000  # Convert seconds to milliseconds
+        else:
+            # 24kHz * 2 bytes per sample
+            return (len(audio_bytes) / (24000 * 2)) * 1000  # Convert seconds to milliseconds
 
     async def _handle_output_item(self, item: ConversationItem) -> None:
         """Handle response output item events (function calls and messages)."""
@@ -439,6 +456,7 @@ async def _handle_ws_event(self, event: dict[str, Any]):
             self._ongoing_response = False
             await self._emit_event(RealtimeModelTurnEndedEvent())
         elif parsed.type == "session.created":
+            self._created_session = parsed.session
             await self._send_tracing_config(self._tracing_config)
         elif parsed.type == "error":
             await self._emit_event(RealtimeModelErrorEvent(error=parsed.error))
diff --git a/tests/realtime/test_openai_realtime.py b/tests/realtime/test_openai_realtime.py
index 5cb0eb0fa..7b1d0b112 100644
--- a/tests/realtime/test_openai_realtime.py
+++ b/tests/realtime/test_openai_realtime.py
@@ -344,17 +344,30 @@ async def test_audio_timing_calculation_accuracy(self, model):
         for event in audio_deltas:
             await model._handle_ws_event(event)
 
-        # Should accumulate audio length: 8 bytes / 24 / 2 = ~0.167ms per byte
-        # Total: 8 bytes / 24 / 2 = 0.167ms
-        expected_length = 8 / 24 / 2
+        # Should accumulate audio length: 8 bytes / (24000 * 2) * 1000 = ~0.167ms total
+        expected_length = (8 / (24000 * 2)) * 1000
         assert abs(model._audio_length_ms - expected_length) < 0.001
 
     def test_calculate_audio_length_ms_pure_function(self, model):
         """Test the pure audio length calculation function."""
-        # Test various audio buffer sizes
-        assert model._calculate_audio_length_ms(b"test") == 4 / 24 / 2  # 4 bytes
+        # Test various audio buffer sizes for PCM16 (default)
+        assert model._calculate_audio_length_ms(b"test") == (4 / (24000 * 2)) * 1000  # 4 bytes
         assert model._calculate_audio_length_ms(b"") == 0  # empty
-        assert model._calculate_audio_length_ms(b"a" * 48) == 1.0  # exactly 1ms worth
+        assert model._calculate_audio_length_ms(b"a" * 48000) == 1000.0  # exactly 1 second worth
+
+    def test_calculate_audio_length_ms_g711_format(self, model):
+        """Test audio length calculation for G.711 format."""
+        from unittest.mock import Mock
+
+        # Mock session with g711 format
+        mock_session = Mock()
+        mock_session.output_audio_format = "g711_ulaw"
+        model._created_session = mock_session
+
+        # Test G.711: 8kHz * 1 byte per sample
+        assert model._calculate_audio_length_ms(b"test") == (4 / 8000) * 1000  # 4 bytes = 0.5ms
+        assert model._calculate_audio_length_ms(b"") == 0  # empty
+        assert model._calculate_audio_length_ms(b"a" * 8000) == 1000.0  # exactly 1 second worth
 
     @pytest.mark.asyncio
     async def test_handle_audio_delta_state_management(self, model):
@@ -376,4 +389,4 @@ async def test_handle_audio_delta_state_management(self, model):
             assert model._current_audio_content_index == 5
             assert model._current_item_id == "test_item"
             assert model._audio_start_time == mock_now
-            assert model._audio_length_ms == 4 / 24 / 2  # 4 bytes
+            assert model._audio_length_ms == (4 / (24000 * 2)) * 1000  # 4 bytes, converted to ms