The current version of macOS High Sierra, a 10.13.6, was released to all users in early July. A few weeks later, however, Apple released a supplemental update specifically to fix performance issues in the recently released ones. MacBooks Pro with Touch Bar.
Today, a second update of these came out (builds 17G2037 and 15P6805) – again, only for MBPs in 2018.
According to Apple, the macOS High Sierra 10.13.6 Supplemental Update 2 «Improves the stability and reliability of MacBook Pro computers with Touch Bar (2018), and is recommended for all users».
The release note does not specify this, but I would not be surprised if the update fixed the “popping” problem on speakers that we covered a few weeks ago. Just a hunch.
It is worth noting that these new machines have not yet arrived in Brazil. The National Telecommunications Agency (Anatel) has already approved the new 13 ″ model, but the 15 ″ is yet to be released.
Update Aug 29, 2018 at 14:55
Confirming my suspicion, Apple declared to the MacRumors that this update does, in fact, also come to solve audio problems in the new MacBooks Pro. And several users have already corroborated its effectiveness in this sense, which is great.