Aporte original por: Rachel Acosta ,
Hi Marco, [post|363311] an answer for the same problem with the iPhone 6, might be a place to start. Between that one and [https://discussions.apple.com/message/26757771#26757771|this one] (also for the 6, unfortunately), I'd say there's probably something covering the rear microphone. [https://discussions.apple.com/message/30911917#30911917|This thread] mentions a problem with the iPhone 7 specifically, but it sounds like theirs is an intermittent problem, whereas yours just doesn't record the sound. Does your iPhone still have the protective cover on the back?