diff --git a/tests/streaming/output_device/test_twilio_output_device.py b/tests/streaming/output_device/test_twilio_output_device.py
index e69de29bb..a2c4ca3e5 100644
--- a/tests/streaming/output_device/test_twilio_output_device.py
+++ b/tests/streaming/output_device/test_twilio_output_device.py
@@ -0,0 +1,139 @@
+import asyncio
+import base64
+import json
+
+import pytest
+from pytest_mock import MockerFixture
+
+from vocode.streaming.output_device.audio_chunk import AudioChunk, ChunkState
+from vocode.streaming.output_device.twilio_output_device import (
+    ChunkFinishedMarkMessage,
+    TwilioOutputDevice,
+)
+from vocode.streaming.utils.worker import InterruptibleEvent
+
+
+@pytest.fixture
+def mock_ws(mocker: MockerFixture):
+    return mocker.AsyncMock()
+
+
+@pytest.fixture
+def mock_stream_sid():
+    return "stream_sid"
+
+
+@pytest.fixture
+def twilio_output_device(mock_ws, mock_stream_sid):
+    return TwilioOutputDevice(ws=mock_ws, stream_sid=mock_stream_sid)
+
+
+@pytest.mark.asyncio
+async def test_calls_play_callbacks(twilio_output_device: TwilioOutputDevice):
+    played_event = asyncio.Event()
+
+    def on_play():
+        played_event.set()
+
+    audio_chunk = AudioChunk(data=b"")
+    audio_chunk.on_play = on_play
+
+    twilio_output_device.consume_nonblocking(InterruptibleEvent(payload=audio_chunk))
+    twilio_output_device.start()
+    twilio_output_device.enqueue_mark_message(
+        ChunkFinishedMarkMessage(chunk_id=str(audio_chunk.chunk_id))
+    )
+
+    await played_event.wait()
+    assert audio_chunk.state == ChunkState.PLAYED
+
+    media_message = json.loads(twilio_output_device.ws.send_text.call_args_list[0][0][0])
+    assert media_message["streamSid"] == twilio_output_device.stream_sid
+    assert media_message["media"] == {"payload": base64.b64encode(audio_chunk.data).decode("utf-8")}
+
+    mark_message = json.loads(twilio_output_device.ws.send_text.call_args_list[1][0][0])
+    assert mark_message["streamSid"] == twilio_output_device.stream_sid
+    assert mark_message["mark"]["name"] == str(audio_chunk.chunk_id)
+
+    twilio_output_device.terminate()
+
+
+@pytest.mark.asyncio
+async def test_calls_interrupt_callbacks(twilio_output_device: TwilioOutputDevice):
+    interrupted_event = asyncio.Event()
+
+    def on_interrupt():
+        interrupted_event.set()
+
+    audio_chunk = AudioChunk(data=b"")
+    audio_chunk.on_interrupt = on_interrupt
+
+    interruptible_event = InterruptibleEvent(payload=audio_chunk, is_interruptible=True)
+
+    twilio_output_device.consume_nonblocking(interruptible_event)
+    # we start the twilio events task and the mark messages task manually to test this particular case
+
+    # step 1: media is sent into the websocket
+    send_twilio_messages_task = asyncio.create_task(twilio_output_device._send_twilio_messages())
+
+    while not twilio_output_device._twilio_events_queue.empty():
+        await asyncio.sleep(0.1)
+
+    # step 2: we get an interrupt
+    interruptible_event.interrupt()
+    twilio_output_device.interrupt()
+
+    # note: this means that the time between the events being interrupted and the clear message being sent, chunks
+    # will be marked interrupted - this is OK since the clear message is sent almost instantaneously once queued
+    # this is required because it stops queueing new chunks to be sent to the WS immediately
+
+    while not twilio_output_device._twilio_events_queue.empty():
+        await asyncio.sleep(0.1)
+
+    # step 3: we get a mark message for the interrupted audio chunk after the clear message
+    twilio_output_device.enqueue_mark_message(
+        ChunkFinishedMarkMessage(chunk_id=str(audio_chunk.chunk_id))
+    )
+    process_mark_messages_task = asyncio.create_task(twilio_output_device._process_mark_messages())
+
+    await interrupted_event.wait()
+    assert audio_chunk.state == ChunkState.INTERRUPTED
+
+    media_message = json.loads(twilio_output_device.ws.send_text.call_args_list[0][0][0])
+    assert media_message["streamSid"] == twilio_output_device.stream_sid
+    assert media_message["media"] == {"payload": base64.b64encode(audio_chunk.data).decode("utf-8")}
+
+    mark_message = json.loads(twilio_output_device.ws.send_text.call_args_list[1][0][0])
+    assert mark_message["streamSid"] == twilio_output_device.stream_sid
+    assert mark_message["mark"]["name"] == str(audio_chunk.chunk_id)
+
+    clear_message = json.loads(twilio_output_device.ws.send_text.call_args_list[2][0][0])
+    assert clear_message["streamSid"] == twilio_output_device.stream_sid
+    assert clear_message["event"] == "clear"
+
+    send_twilio_messages_task.cancel()
+    process_mark_messages_task.cancel()
+
+
+@pytest.mark.asyncio
+async def test_interrupted_audio_chunks_are_not_sent_but_are_marked_interrupted(
+    twilio_output_device: TwilioOutputDevice,
+):
+    interrupted_event = asyncio.Event()
+
+    def on_interrupt():
+        interrupted_event.set()
+
+    audio_chunk = AudioChunk(data=b"")
+    audio_chunk.on_interrupt = on_interrupt
+
+    interruptible_event = InterruptibleEvent(payload=audio_chunk, is_interruptible=True)
+    interruptible_event.interrupt()
+
+    twilio_output_device.consume_nonblocking(interruptible_event)
+    twilio_output_device.start()
+
+    await interrupted_event.wait()
+    assert audio_chunk.state == ChunkState.INTERRUPTED
+
+    twilio_output_device.ws.send_text.assert_not_called()