Set the land to "Restrict gesture and object sounds to this parcel"
Login with the mobile viewer.
Some sounds from neighbors are still audible, but not all of them.
According to Firestorm's Sound Explorer it's sounds from llLoopSound that remain audible in the mobile viewer but not sounds from llPlaySound.
https://secondlife.canny.io/admin/feedback/mobile-public-beta-bugs/p/i-can-still-hear-sounds-from-neighboring-parcels-that-are-not-audible-in-other-v
Set the land to "Restrict gesture and object sounds to this parcel"
Login with the mobile viewer.
Some sounds from neighbors are still audible, but not all of them.
According to Firestorm's Sound Explorer it's sounds from llLoopSound that remain audible in the mobile viewer but not sounds from llPlaySound.
https://secondlife.canny.io/admin/feedback/mobile-public-beta-bugs/p/i-can-still-hear-sounds-from-neighboring-parcels-that-are-not-audible-in-other-v