Continuing with the plasterboard installation, and once all the first layer of plasterboard is installed, I sealed all the edges with silicon sealant. This will limit the air movements and help with soundproofing. Though there are two 150mm diameter air ducting with vents for air to move in and out from, this affects the lower frequencies, especially in corners, forcing sound pressure to only access from the ducts and not from everywhere.
Next I do a quick noise test with my vacuum cleaner. We soon discover how the door will be our weakest point, since it’s only one door and does not even have any seals.