Simple audio tutorial: macOS fix, typo, do not mix label variables

[AndiDog]

The tutorial outcome is currently confusing since the plot shows a totally different prediction than the speech file. In the graph, "go" is allegedly predicted:

This fixes the bug by using the correct variable for plot labels.

Plus minor fixes (see commit message).

Not sure

[github-actions]

Preview

Preview and run these notebook edits with Google Colab:

• site/en/tutorials/audio/simple_audio.ipynb

Rendered notebook diffs available on ReviewNB.com.

Format and style

Use the TensorFlow docs notebook tools to format for consistent source diffs and lint for style:

$ python3 -m pip install -U --user git+https://github.com/tensorflow/docs

$ python3 -m tensorflow_docs.tools.nbfmt notebook.ipynb

$ python3 -m tensorflow_docs.tools.nblint --arg=repo:tensorflow/docs notebook.ipynb

If commits are added to the pull request, synchronize your local branch: git pull origin patch-1

[8bitmp3]

Thanks @AndiDog

[MarkDaoust]

Thanks!