No way: products break down and fail, no matter how tight the quality control of companies (or most of them at least) is getting tighter. When these failures affect an unusually large number of devices, what is expected of the manufacturer to recognize the problem and offer satisfactory solutions to consumers, right? Fortunately, what Apple usually does and is doing today.
As reported by MacRumors, Ma acknowledged the existence of a failure affecting an unspecified number of iPhones 7 and 7 Plus running the iOS 11.3 or superior. The problem affects the microphone device and causes users to have trouble hearing during phone calls or via FaceTime; In addition, affected devices have the speakerphone button grayed out and inactive during calls.
There is still no information about what is causing the problem, nor a reason why a software update is causing a hardware problem (apparently, as several devices are actually being replaced once the problem is detected).
In an internal document distributed to Apple's official stores and Apple Authorized Service Centers, the company instructs technicians to first ask consumers to turn off Bluetooth on the device to see if the problem persists. If so, audio diagnostics should be run on the iPhone for fault detection; once discovered, the device is referred for repair or exchange.
Apple further advises that technicians may apply for an exception for devices whose warranty has expired and, although it is not clear that repair / replacement is free of charge, if this is believed to be the case. So if your iPhone is experiencing the problem, schedule a visit to a store or a nearby CSAA, and then, of course, tell us about your experience there.