In Drowtales, Bards can use magic to raise the volume of their voice to metal-concert levels. In combination with an empath plying the minds of their enemies to be suggestive, they can force entire armies to literally sit down and wait for their execution.
Very frustrated Mikilu picks up a rock, throws it in the air and scream at it to destroy it. It may be partially magic, as she is powerful. A mighty scream indeed.
Gantus from Furry Fight Chronicles can bark so loud that he creates shock waves. It manages to intimidate Kalita into retreating.
The Rumbletoys in Girl Genius uses subsonic wave throwers to liquefy rock. It's often used for road construction purposes, but it could easily double as a siege weapon.
In The Inexplicable Adventures of Bob!, Jean's shouting ability may not be literally superhuman, but it's danged impressive. Most of the local sasquatch clan are scared to death of it.
Tsukiko in The Order of the Stick uses the spell called Shout to kill a Chlorine Elemental. It is a standard Dungeons & Dragons spell (as described in the Tabletop Gaming section).
Related to this trope is that the druid Leeky Windstaff's walking tree minions are only vulnerable to sonic attack. Durkon uses thunder to achieve this effect.
In Pacificators, this is one of the two types of the power of air (the other is Blow You Away). Generally, most of users of air could do both. The people we know of who have this power are Taffe, Gincoi, and Enlil. However, they don't always attack by shouting; sometimes, clapping does the trick. Another neat trick they can do is whisper and have it carry far.◊
In an interesting case of Combat Pragmatist, Taffe won against Gincoi twice because he doesn't know that she's deaf. See his shock and confusion when his attack failedtwice. (The last link also contains a more typical Make Me Wanna Shout attack, done via voice. The last two links contains spoilers, however, so click at your own risk.)
In Rusty and Co. the bard Roxanne is seen learning the Shout spell with the help of the wizard Prestige, and she later uses it to great effect against the gnoll Grinner.
