They will perceive sounds differently, yet the audiogram suggests that they have the same degree of loss. Huss and Moore investigated how hearing impaired patients perceive pure tones, and found that they perceive tones as noisy and distorted, more (on average) than a person without a hearing impairment. However, they also found that the perception of tones as being like noise, was not directly related to frequencies within the dead regions, and was therefore not an indicator of a dead region. This therefore suggests that audiograms, and their poor representation of dead regions, are inaccurate predictors of a patients perception of pure tone quality.Research by Kluk and Moore  has shown that dead regions may also affect the patients perception of frequencies beyond the dead regions. There is an enhancement in the ability to distinguish between tones that differ very slightly in frequency, in regions just beyond the dead regions compared to tones further away. An explanation for this may be that cortical re-mapping has occurred. Whereby, neurons which would normally be stimulated by the dead region, have been reassigned to respond to functioning areas near it. This leads to an over-representation of these areas, resulting in an increased perceptual sensitivity to small frequency differences in tones. Vestibulocochlear nerve pathology
congenital deformity of the internal auditory canal,
neoplastic and pseudo-neoplastic lesions, with special detailed emphasis on schwannoma of the eighth cranial nerve (acoustic neuroma),
non-neoplastic Internal Auditory Canal/CerebelloPontine Angle pathology, including vascular loops,

Diagnosis
Case history
Before examination, a case history provides guidance about the context of the hearing loss.
SNHL is at least partially preventable by avoiding environmental noise, ototoxic chemicals and drugs, and head trauma, and treating or inoculating against certain triggering diseases and conditions like meningitis. Signs and symptoms
Since the inner ear is not directly accessible to instruments, identification is by patient report of the symptoms and audiometric testing. Of those who present to their doctor with sensorineural hearing loss, 90% report having diminished hearing, 57% report having a plugged feeling in ear, and 49% report having ringing in ear (tinnitus). About half report vestibular (vertigo) problems. For a detailed exposition of symptoms useful for screening, a self-assessment questionnaire was developed by the American Academy of Otolaryngology, called the Hearing Handicap Inventory for Adults (HHIA). It is a 25-question survey of subjective symptoms. Causes
Sensorineural hearing loss may be genetic or acquired (i.e. as a consequence of disease, noise, trauma, etc.). People may have a hearing loss from birth (congenital) or the hearing loss may come on later. Many cases are related to old age (age-related). Genetic
Hearing loss can be inherited. More than 40 genes have been implicated in the cause of deafness. There are 300 syndromes with related hearing loss, and each syndrome may have causative genes. Recessive, dominant, X-linked, or mitochondrial genetic mutations can affect the structure or metabolism of the inner ear. Some may be single point mutations, whereas others are due to chromosomal abnormalities. Some genetic causes give rise to a late onset hearing loss. Mitochondrial mutations can cause SNHL i.e.