Apple received several complaints that the iPhone 7 and 7 plus makes a hissing or buzzing sound.
It's heard when owners use processor-intensive apps or when they restore their iCloud data.
There are other reports that say some users coming across a bug in the lightning earpods. Physical controls like volume, Siri or the ability to answer calls gets turned off when the earpods are plugged into the lightning port for a few minutes.
A quick fix is unplugging the earpods and plugging them back in. Apple says a future software update will fix the problem.