I haven't seen any microphone integrated in the processor.
Yet
They are very low level input and generally need a pre-amp just to get the signal outside the microphone. However conceptually at least they are there and so maybe someone can get it to work.
Are there examples of using IMUs to get audio data you could point to? A quick search didn't reveal anything.
And there's this post, which includes an audio clip: https://goughlui.com/2019/02/02/weekend-project-mma8451q-acc...