diff --git a/speech/cloud-client/transcribe_streaming.py b/speech/cloud-client/transcribe_streaming.py
index 6a1be800b450..fafb3b062b45 100644
--- a/speech/cloud-client/transcribe_streaming.py
+++ b/speech/cloud-client/transcribe_streaming.py
@@ -41,6 +41,7 @@ def transcribe_streaming(stream_file):
         sample_rate_hertz=16000,
         language_code='en-US')
 
+    # In practice requests should be a generator yielding chunks of audio data.
     requests = [request]
     streaming_config = types.StreamingRecognitionConfig(config=config)