Updated! Apple releases macOS High Sierra Supplementary Update for 2018 MacBook Pro users.
Update: After being asked by MacRumors, Apple has given a statement saying the Supplemental Update improves system stability and reliability across a number of areas, and addresses several issues, including crackling audio and kernel panics. Apple said it recommends all users install the update on their MacBook Pros.
As the update hasn't been out for long, there is no evidence of the update fixing the issues. However, Apple Support Communities user takashiyoshida says his MacBook Pro "no longer outputs the crackling noise" after updating.
Some have commented however, saying the issue is still apparent in specific applications like Safari, but works in others such as Spotify). He noted that there "were no issues with the Spotify app after updating".
Kernel panics have still been reported by users, even after updating.
It's claimed that Apple also asked a few customers if they were willing to send in their MacBook so that their engineers could look into the issues. Users told MacRumors that fixes were apparently in the works.
The update is not available to macOS Mojave users.
Original article below
The new update, 10.13.14 Update 2/ Supplementary Update, is available for all High Sierra-compatible computers, but specifically improves Touch Bar performance on 2018 models.
The release notes state the following:
The macOS High Sierra 10.13.6 Supplemental Update 2 improves the stability and reliability of MacBook Pro with Touch Bar (2018) computers, and is recommended for all users.
Its unknown if the update only improves Touch Bar stability on these machines and unclear if any bugs have been fixed. It’s possible the update also fixes speaker issues that users have experienced.