I can't what IC38 is from the numbers on it. I agree that it looks like an audio IC, but I think that it is the power amplifier that drives the headphone socket via the two electrolytic capacitors.
Quite correct.... I was just admiring your logic....The OP wanted to find the ADC, not the output amplifier.
I would agree that's the one.
Two channels for the built-in mics (probably IC34 as it's very close to the preamps) and two more for the XLR mic inputs?It actually contains an ADCs, as well as a DACs, so I'm not sure why the design needs the AKM5357 ADC as well. However, there are lots of possible reasons why separate ICs could be needed.