The Chihuahua's 5/5 is the top of the scale and the most common reason people give up on the breed.
It announces the door, the corridor, the lift, the neighbour's television and any dog it can see from a window. It is alert, opinionated, and physiologically built to produce a sound that carries far further than its size suggests. In a flat with shared walls, that becomes a relationship with your neighbours rather than a habit of your dog.
It trains down and not out. Blocking sightlines, teaching a settled alternative and rewarding quiet all reduce it substantially, but the breed's baseline is high.
The Malamute at 3/5 is not quiet either, and its voice is a different problem: Malamutes howl, and a howling hundred-pound dog in a garden carries across a neighbourhood. The difference is frequency rather than volume — a well-exercised Malamute is largely silent, while a Chihuahua's barking is not primarily an exercise problem.
Both rate 2/5 for solitude, and in both breeds noise is worst when the dog is alone.