Hear Heartbeat

For the duration of this spell, a priest becomes completely deaf to all normal sounds and may hear only the noise of other creatures' beating hearts. The heartbeat of each person, animal, or monster in the area of effect is clearly distinct and may convey information about the being's proximity, direction, size, emotional distress, general health, and race or species. For instance, the heartbeat of a frail old wizard would be much softer and weaker than that of the invisible ogre bodyguard, standing behind him. This spell can provide quite confusing results if cast in the presence of numerous individuals (such as on a crowded city street) and is most effective when cast by a cleric in relative seclusion. A priest never hears his or her own heartbeat with this spell. It is effectively masked out by the power of the hear heartbeat spell.
Obviously, this spell is of little use with creatures without functioning hearts (such as plants or undead). The spell's range is diminished if more than a one-inch thickness of wood, stone, or metal lies between the caster and a subject. Each inch of a barrier's thickness should be treated as 10' of open space.
The drop of blood blocks the sound of the caster's own heartbeat. While casting the spell, the priest places the wax in his ears to blot out normal sound and trigger the magical effect. Note that the priest is completely oblivious to normal sounds (such as talking or music) while the spell is in effect.

[Complete Book of Necromancers]

Sphere: Divination, Necromantic
(Divination, Necromancy)
Level: 2

Range: 0
Components: V, S, M
Duration: 1 turn + 2 rounds/ level
Casting Time: 1 round
Area of Effect: 10' radius/level
Saving Throw: None

Material Components:
beeswax mixed with a tiny drop of the priest's own blood