Okay, I did some more research on why the ear slap works...and nekogami13 is right the ear slap SHOULD NOT be able to kill anybody but i'm not going to say it 'never will kill anyone' there are freak accidents or just associated things to cause death. However it can cause a perforated eardrum...
A perforated eardrum is a hole or rupture in the eardrum, a thin membrane that separates the ear canal and the middle ear. The medical term for the eardrum is tympanic membrane. The middle ear is connected to the nose by the Eustachian tube, which equalizes pressure in the middle ear and the atmospheric air.
The causes of perforated eardrum are usualy from trauma or infection. A perforated eardrum can occur:-
* If the ear is struck squarely with an open hand as in a slap.
* With a skull fracture (after road traffic accidents)
* After a sudden explosion (e.g. bomb blast)
* If an object (Such as a bobby pin, ear bud, sticks or keys) is pushed too far into the ear canal.
* As a result of hot liquids or acid entering the ear canal
Middle ear infections may cause pain, hearing loss and spontaneous rupture (tear) of the eardrum resulting in a perforation. In this circumstance, there may be infected or bloody drainage from the ear. In medical terms, this is called otitis media with perforation.
Most eardrum perforations heal spontaneously with weeks after rupture, although some may take up to several months. During the healing process the ear must be protected from water and trauma. Those eardrum perfor-ations, which do not heal on their own, may require surgery.
Effects on Hearing from perforated ear drum
Usually, the larger the perforation, the greater the loss of hearing. The location of the hole (perforation) in the eardrum also effects the degree of hearing loss. If severe trauma (e.g skull fracture) disrupts the bones in the middle ear which transmit sound or causes injury to the inner ear structures, the loss of hearing may be quite severe.
If the perforated eardrum is due to a sudden traumatic or explosive event, the loss of hearing can be great and ringing in the ear (tinnitus) may be severe. In this case the hearing usually returns partially, and the ringing diminishes in a few days. Chronic infection as a result of the perforation can cause major hearing loss.
So a slap to an ear will 'shock' or 'stun' and might screw up the equilibrium for a few seconds of the person after the slap (Precious seconds to attack)
P.S. Since I do not want to be charged with plagirism I'm going to put the source of info. for the 'perforated eardrum'
http://www.pondy-central.com/grapevine/msg00037.html#D7