Some early iPhone 7 & 7 Plus users are reporting sound quality issues during calls, according to Apple Insider. Owners of the iPhone 7 Plus posted on Apple Communities that the call audio sounds "distant."
A couple of people who took their phones to Apple's Genius Bar for a diagnostics test were told it was an issue with their service provider. Users with both Verizon and AT&T reported having this sound issue. In some cases, users had their phones replaced altogether in order to solve the issue, which means this problem is not plaguing all iPhone 7 & 7Plus phones. RR