Speech API asynchrecognize returning without transcription #747

In which file did you encounter the issue?

transcribe_async.py

Did you change the file? If so, how?

No

Describe the issue

I ran the async transcription but there are no results:

$> python transcription.py 30\ Second\ Elevator\ Speech.mp3
"name": "2031513765692485155"}
Waiting for server processing...
Waiting for server processing...
Waiting for server processing...
Waiting for server processing...
Waiting for server processing...
{"response": {"@type": "type.googleapis.com/google.cloud.speech.v1beta1.AsyncRecognizeResponse"}, "done": true, "name": "2031513765692485155", "metadata": {"lastUpdateTime": "2017-01-05T21:00:59.102697Z", "@type": "type.googleapis.com/google.cloud.speech.v1beta1.AsyncRecognizeMetadata", "startTime": "2017-01-05T21:00:18.750814Z", "progressPercent": 100}}

Is this because I am giving an mp3? Why isn't including any alternatives?