It’s a straightforward two-step process.

One: make sure you have version 1.0.0 or later of google-cloud-speech (use !pip freeze | grep google-cloud-speech)

Two: Instead of importing the client libraries like

from google.cloud import speech
from google.cloud.speech import enums, types

import them like

from google.cloud import speech_v1p1beta1 as speech, storage
from google.cloud.speech_v1p1beta1 import enums, types

The beta features should now be available for you to use.