google-cloud-python: Unsuccessful authentication without errors/warnings

At first the authentication worked fine and I could see the API requests in the dashboard. But at some point the requests were not showing up anymore in the dashboard API overview.

I created a service account and stored the json file locally. Then I set the environment variable GCLOUD_PROJECT to the project ID and GOOGLE_APPLICATION_CREDENTIALS to the path of the json file.

from google.cloud import speech
client = speech.Client()
print(client._credentials.service_account_email)

Prints the correct service account email.

import io
with io.open(audio_file, 'rb') as f:
    audio = client.sample(f.read(), source_uri=None, sample_rate=48000, encoding=speech.encoding.Encoding.FLAC)
alternatives = audio.sync_recognize(language_code='de-DE')

The resulting transcript is correct, but nothing happens on the dashboard at https://console.cloud.google.com/apis/api/speech.googleapis.com/overview?project=[project-ID]

I also tried to initialize the client with the function speech.Client.from_service_account_json and to authenticate by installing the Google Cloud SDK and gcloud auth application-default login, but without success.

The error count (Fehler) is increasing here but I don’t know how to get additional information.

• Windows 7
• conda environment
• python 3.5.2
• google-cloud-speech 0.23.0