  We summarize the results of a host of efforts using giant automatic speech
recognition (ASR) models pre-trained using large, diverse unlabeled datasets
containing approximately a million hours of audio. We find that the combination
of pre-training, self-training and scaling up model size greatly increases data
efficiency, even for extremely large tasks with tens of thousands of hours of
labeled data. In particular, on an ASR task with 34k hours of labeled data, by
fine-tuning an 8 billion parameter pre-trained Conformer model we can match
state-of-the-art (SoTA) performance with only 3% of the training data and
significantly improve SoTA with the full training set. We also report on the
universal benefits gained from using big pre-trained and self-trained models
for a large set of downstream tasks that cover a wide range of speech domains
and span multiple orders of magnitudes of dataset sizes, including obtaining
SoTA performance on many public benchmarks. In addition, we utilize the learned
representation of pre-trained networks to achieve SoTA results on non-ASR
tasks.
