Hearing verbal components

[ffone]

Frequent situation: PCs spellcast buffs when they can't be seen but might be heard. What's the Listen DC? The 'people talking ' entry of Listen? 'Whispering'? Can a caster improve at quiet casting (short of Silent Spell) via Move Silently or other skills?

[Jarian]

RAW, there is no official rule regarding this, as far as I know, aside from specifying that you must speak in a "clear, firm voice". For me, this means a base Listen DC of 0, modified by distance and other appropriate modifiers (doors, walls, etc).

[Re'ozul]

Bards and Beguilers (and maybe some more) can use Zone of Silence (http://www.d20srd.org/srd/spells/zoneOfSilence.htm) for that, though of course the question is wether they can hear you casting that spell. (i.e. does the spell cover the verbal component of its own creation)

[Andion Isurand]

My "flagship" character wears a mask to slightly diminish the sound made when casting spells with verbal components, but also so his lips aren't read.