From what you described m, it sounds like you have damage to your front camera assembly flex cable which has you ear speaker connection on it. This also contact FaceTime audio. If this component fails, it can have some components work, such as camera but not audio. Or Siri not working. Try replacing this component to see if this works. Here is a guide and where to buy the parts. I would also replace the ear speaker mesh at the same time. Try this and let me know if it works or not.
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