Linked Perception

(Player's Handbook II, DnD 3.5)

Divination

Level: ; Druid 2; Ranger 1
Components: V
Casting Time: 1 standard action
Range: 20 ft.
Area: 20-ft.-radius emanation centered on you
Duration: 1 minute/level (D)
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)

Your senses are muddied for a moment, but when they clear, your sight and hearing are improved.
This spell imparts to all allies in its area a shared awareness of their surroundings.
Each ally in the area (including yourself ) gains a +2 bonus on Spot and Listen checks per each ally in the area.
For example, if you and three allies are in the area, each of you gains a +6 bonus.