Amplify

Magic of Faerûn (Mag)Updated Forgotten Realms (3.0)

Amplify is a D&D 3.5 spell (Transmutation) from Mag. On class lists for Bard (Level 1), Bard Variant (Level 1), Divine Bard (Level 1), and others. Range or area: Long (400 ft. + 40 ft./level); Saving throw: Will negates; Duration: 1 round/level; Casting time: 1 minute/level.

School
Transmutation
Casting Time
1 minute/level
Components
V, S
Range
Long (400 ft. + 40 ft./level)
Target
All emitted sounds within 15 ft. of the target
Area
15 ft. radius emanation centered on a creature, object, or point in space
Duration
1 round/level
Saving Throw
Will negates
Spell Resistance
Yes or No (object)

You cause an amplification of all sounds within the spell’s area.
This decreases the DC to hear those sounds by 20.
Those creatures within the spell’s area do not notice the increased amplification.
Thus, anyone whose voice is amplified remains unaware of the increase in volume.