Apple knows about the problem with iPhone 7’s audio chip but they do not want to fix it for free. There is a class action lawsuit right now. You can google it to find out. My spouse bought a used iPhone7 from a Walmart reseller - it had the same problem as mentioned above. The second purchase from a different Walmart reseller had the same problem (by the way, he was unable to return the first phone since he did not realize that the return period was only for two weeks). I love Apple products but Apple (the company) do not seem to care about their customers.