If you own a Moto G5 Plus in India you should have received the over-the-air update notification for August Security Patch, and it's crucial that you download it, as it brings along the fix for phone audio issue.
The update costs in at around 53.9MB and comes with build number NPN25.137-67-5. Note that the device still remains on Android 7.0 Nougat.
August Android security update also resolves tons of issues dated 2017-08-01. The most severe of these issues is a critical security vulnerability in media framework that could enable a remote attacker using a specially crafted file to execute arbitrary code within the context of a privileged process. The severity assessment is based on the effect that exploiting the vulnerability would possibly have on an affected device, assuming the platform and service mitigations are turned off for development purposes or if successfully bypassed.