How do I make a sound play in one area only?

Insert a script into a local script, put it in the startergui, and try something like this.

local Player=game.Players.LocalPlayer
Song=game.Workspace.Sound:clone()
function Touched()
    if Player.PlayerGui:FindFirstChild("Sound")==nil then
        Song.Parent=Player.PlayerGui
        Song.Volume=2
        Song:Play()
        Song.Looped=true --set this to true or false--
    end
end

function TouchedE()
    if Player.PlayerGui:FindFirstChild("Sound")~=nil then
        Player.PlayerGui:FindFirstChild("Sound"):remove()
    end
end

--Change 'Part' to the name of the brick touched.
game.Workspace.Part.Touched:connect(Touched)
game.Workspace.Part.TouchEnded:connect(TouchedE)

Hopefully this'll work. It should if you do what It says.