Hypersensitivity Simultaneously in Ear canals
This answer is based on embryological studies and is limited. 
I will extend it later when understand better.

Sensory areas


maculae acusticae - walls of utricle and saccule (this most probable area)
cristae acusticae - change in body position


Nerve 


vestibular fibers of cranial nerve VIII (TODO each branchial arch has a nerve - how these differentiate between different arches?)


Embryonal Ganglion


statoacoustic (spinal) ganglion (19.5 C Fig)


Embryonal ganglion splits into two 


cochlear portion
vestibular portion


which supply sensory cells of organ of Corti, and those of the saccule, utricle and semicircular canals, respectively

Branchial Arches

Each arch has a vessel, cartilage and nerve. 
The task is to understand which part of embryonal ear is able to start hypersensitivity reaction. 

Middle ear

Tympanic Cavity and Auditory Tube


origin endoderm (1st pharyngeal pouch) - malleus and incus
malleus - 2nd a.a.a.


Eardrum or Tympanic Membrane


ectodermal epithelial lining at bottom of auditory meatus
endodermal epithelial lining of the tympanic cavity
intermediate layer of connective tissue (See Langmans' Fig 19.9B). TODO this part is superficially covered in Langmans. 


Auricle


6 mesenchymal proliferations at dorsal ends of 1-2 a.a.a.


TODO I must look again embryonal slides of ear to see where the nerves occur first and how they develop. 

Sources


Langmans Medical Embryology, 12th ed, 2011
My notes of Embryology classes, Spring 2014 (I did not have all my notes now so must study these things again after holiday)