Described by users as "very annoying", the bug was first discovered shortly after launching iOS 11 at the end of September. At that time, Apple said it was trying to fix the error and will fix it in the next update . For users who encounter this error, the only way to avoid using a headset or speakerphone, changing mobile network settings or rebooting the device is not helpful.
After updating iOS 11.0.2, iPhone 8 and iPhone 8 Plus will not encounter this sound error when making a call. This update also fixes errors that make some images hidden and fixes some errors related to email.
iOS 11 is a major update for iOS operating system, introduces new designed lock screen, customized Control Center, more natural Siri voice, redesigned App Store, new HEVC and HEIF codecs for images and better video and completely change the look of the iPad.