Hearing impairment classification

Hearing impairment Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
CT
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Social Impact
Future or Investigational Therapies
Case Studies
Case #1
Hearing impairment On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Hearing impairment All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Hearing impairment
CDC on Hearing impairment
Hearing impairment in the news
Blogs on Hearing impairment
Directions to Hospitals Treating Hearing impairment
Risk calculators and risk factors for Hearing impairment

Classification

Hearing losses can be classified according to:

1. Laterality,
2. Symmetry,
3. Clinical characteristic (syndromic or not),
4. Time of onset (congenital, perinatal, or postnatal),
5. Hereditary (genetic or not),
6. Time of manifestation (prelingual, perilingual, or post-lingual),
7. Intensity (mild, moderate, severe, and profound)

CLASSIFICATION BASED OF SEVERITY OF DISEASE

	MILD	MODERATE	SEVERE	DISABLING
HEARING LOSS	26–40 dB HL	41–60 dB HL	61–80 dB HL	>80 dB HL
DESCRIPTION	Patient hears fine	Hear with some difficulty. People Mumble.	Difficulty in hearing.	Patients relies on reading lips. The term deaf is often used by persons with profound hearing loss with >80 dB HL.
INTERVENTION	Communication strategies	Communication strategies Amplification	Communication strategies Hearing aids Cochlear implant	Communication strategies Hearing aids Cochlear implant Sign language Lip reading

CLASSIFICATION BASED ON ANATOMY OF EAR

CONDUCTIVE	SENSORINEURAL	MIXED
CHL occurs when sound is not conducted efficiently through the outer ear canal to the middle ear.	SNHL occurs when there's damage to the internal ear or to the nerve pathways from the ear to the brain that is vestibulocochlear nerve or sensory relay center for auditory stimulus. So injury at the cochlea or proximal to the cochlea is termed as SNHL.	Mixed HL is defined as CHL and SNHL.
CHL accounts for 90%–95% of all childhood HL.	SNHL is far more common in adults.
With pure conductive hearing loss, the quality of hearing and speech discrimination is good.
Often only mild and is never worse.	It can be mild, moderate, or severe, including complete deafness.
Common causes in adults include: Cerumen impaction Otosclerosis Cholesteatoma Otitis media with effusion. Ear canal obstruction Middle-ear abnormalities Tympanic membrane Ossicles	If SNHL takes hours or days to develop it can be due to: Labyrinthitis Meniere disease If hearing loss develops in weeks: Drug-induced ototoxicity If happens in years: Noise-induced loss

CLASSIFICATION BASED ON CAUSE

CONGENITAL

ACQUIRED

Syndromes Dysplasia: Children with skeletal dysplasias were more likely to have abnormal tympanometry, reflecting the greater likelihood of middle ear disease. Infections: Cytomegalovirus (CMV), rubella virus, Toxoplasma gondii, herpes virus, and HIV Malformations

Infections: Bacterial meningitis, particularly from Streptococcus pneumoniae, has been reported to be one of the most common postnatal causes of hearing loss in children. Traumatic Autoimmune: Systemic diseases that cause hearing loss include systemic lupus erythematosus, rheumatoid arthritis, myasthenia gravis, and Hashimoto's thyroiditis Neoplastic: Direct compression of the cochlear nerve by the tumor, occlusion or vascular compression of the internal auditory artery, intratumor bleeding, internal auditory channel occlusion, and toxic substances produced by the tumor that causes degeneration of the inner ear.