<P> Since the Japanese language uses two writing directionalities (vertical, which is the traditional direction; and horizontal, as most other languages), manga has a convention of representing translated foreign speech as horizontal text . </P> <P> It is a convention in American comics that the sound of a snore is represented as a series of Z's, dating back at least to Rudolph Dirks' early 20th - century strip The Katzenjammer Kids . This practice has even been reduced to a single letter Z, so that a speech bubble with this letter standing all alone (again, drawn by hand rather than a font type) means the character is sleeping in most humorous comics . This can be seen, for instance, in Charles Schulz's Peanuts comic strips . </P> <P> Originally, the resemblance between the' z' sound and that of a snore seemed exclusive to the English language, but the spread of American comics has made it a frequent feature in other countries . An exception to this is in Japanese manga, where the usual symbol for sleep is a large bubble coming out of the character's nose . </P> <P> Singing characters usually have musical notes drawn into their word balloons . Archie Comics' Melody Valentine, a character in their Josie and the Pussycats comic, has musical notes drawn into her word balloons at all times, to convey that she speaks in a sing - song voice . </P>

Where did the saying on the bubble come from