Hearing impairment classification: Difference between revisions

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__NOTOC__
__NOTOC__
{{Hearing impairment}}
{{Hearing impairment}}
{{AB}}
 
{{CMG}} {{AE}}
 
==Overview==
==Overview==
Classification is based on [[laterality]], [[severity]], [[Causes|cause]], [[anatomy]] of ear, [[symmetry]], [[clinical]] characteristics, [[age of onset]], and [[Symptoms|associated symptoms]].
==Classification==
==Classification==
===Conductive===
Hearing losses can be classified according to:<ref name="pmid332536102">{{cite journal| author=Nieman CL, Oh ES| title=Hearing Loss. | journal=Ann Intern Med | year= 2020 | volume= 173 | issue= 11 | pages= ITC81-ITC96 | pmid=33253610 | doi=10.7326/AITC202012010 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=33253610  }}</ref>


'''Conductive hearing loss''' occurs when sound is not normally conducted through the outer or middle ear (or both)<ref>
#[[Laterality]]
{{cite web|url=http://www.asha.org/public/hearing/disorders/types.htm|title=Types of Hearing Loss|accessdate=2007-09-24}}
#[[Symmetry]]
#Clinical characteristic (syndromic or not)
#Time of onset ([[congenital]], [[perinatal]], or [[postnatal]])
#[[Hereditary]] ([[Genetics|genetic]] or not)
#Time of manifestation ([[Prelingual deafness|prelingual]], [[perilingual]], or [[Post-lingual deafness|post-lingual]])
#Intensity (mild, moderate, severe, and profound)


</ref>. Since sound can be picked up by a normally sensitive inner ear even if the ear canal, ear drum, and ear ossicles are not working, conductive hearing loss is often only mild and is never worse than a moderate impairment. Hearing thresholds will not rise above 55-60 dB from outer or middle ear problems alone. Generally, with pure conductive hearing loss, the ''quality'' of hearing (speech discrimination) is good, as long as the sound is amplified loud enough to be easily heard.
{| class="wikitable"
|+CLASSIFICATION BASED OF SEVERITY OF DISEASE<ref name="pmid33253610">{{cite journal| author=Nieman CL, Oh ES| title=Hearing Loss. | journal=Ann Intern Med | year= 2020 | volume= 173 | issue= 11 | pages= ITC81-ITC96 | pmid=33253610 | doi=10.7326/AITC202012010 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=33253610  }}</ref>
!
!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 rely on reading lips.
The term ''deaf'' is often used by persons


A conductive loss can be caused by any of the following:
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]]
|}
<br />
{| class="wikitable"
|+CLASSIFICATION BASED ON ANATOMY OF EAR<ref name="pmid27299892">{{cite journal| author=Kral A| title=[Pathophysiology of hearing loss : Classification and treatment options]. | journal=HNO | year= 2017 | volume= 65 | issue= 4 | pages= 290-297 | pmid=27299892 | doi=10.1007/s00106-016-0183-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27299892  }}</ref>
!CONDUCTIVE
!SENSORINEURAL
!MIXED
|-
|CHL occurs when sound is not conducted efficiently through the [[external ear|outer ear]] canal to the middle ear due to any cause.
|SNHL occurs when there's damage to the [[inner ear|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 more common in adults.
|
|-
|With pure conductive hearing loss, the ''quality'' of hearing and [[Speech communication|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|Otitis media with effusion.]]
*[[Ear canal]] obstruction
*[[Ear canal]] obstruction
*Middle-ear abnormalities
*Middle-ear abnormalities
**[[Tympanic membrane]]
**[[Tympanic membrane]]
**[[Ossicles]]
**[[Ossicles]]
|If SNHL takes hours or days to develop it can be due to:


===Sensorineural hearing loss===
*[[Labyrinthitis]]
*[[Meniere's Disease|Meniere disease]]


{{main|Sensorineural hearing loss}}
If hearing loss develops in weeks:


A sensorineural hearing loss is due to insensitivity of the [[inner ear]] (the [[cochlea]]), or to impairment of function in the auditory nervous system.  It can be mild, moderate, or severe, including total deafness.  This is classified as a disability under the [[Americans with Disabilities Act of 1990|ADA]] and if unable to work is eligible for disability payments.<ref>http://www.eeoc.gov/facts/deafness.html Hearing impairment and the Americans with Disabilities Act</ref>
*[[Drug-induced|Drug-induced ototoxicity]]


The great majority of human sensorineural hearing loss is caused by abnormalities in the [[hair cells]] of the [[organ of Corti]] in the cochlea. There are also very unusual sensorineural hearing impairments that involve the VIIIth [[cranial nerve]] (the [[Vestibulocochlear nerve]]) or the auditory portions of the brain. In the rarest of these sorts of hearing loss, only the auditory centers of the brain are affected. In this situation, [[central hearing loss]], sounds may be heard at normal thresholds, but the quality of the sound perceived is so poor that speech can not be understood.
If happens in years:


Most sensory hearing loss is due to poor hair cell function. The hair cells may be abnormal at birth, or damaged during the lifetime of an individual. There are both external causes of damage, like noise trauma and infection, and intrinsic abnormalities, like deafness genes.
*[[Noise-induced hearing loss|Noise-induced loss]]
|
|}
{| class="wikitable"
|+CLASSIFICATION BASED ON CAUSE<ref name="pmid272998922">{{cite journal| author=Kral A| title=[Pathophysiology of hearing loss : Classification and treatment options]. | journal=HNO | year= 2017 | volume= 65 | issue= 4 | pages= 290-297 | pmid=27299892 | doi=10.1007/s00106-016-0183-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27299892  }}</ref><ref name="pmid26452421">{{cite journal| author=Kenna MA| title=Acquired Hearing Loss in Children. | journal=Otolaryngol Clin North Am | year= 2015 | volume= 48 | issue= 6 | pages= 933-53 | pmid=26452421 | doi=10.1016/j.otc.2015.07.011 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26452421  }}</ref>
!CONGENITAL
!ACQUIRED
|-
|
*[[Syndromes]]
*[[Dysplasia]]: Children with skeletal dysplasias were more likely to have abnormal [[tympanometry]], reflecting the greater likelihood of middle ear disease.
*[[Infections|Infections:]] ''Cytomegalovirus'' (CMV), rubella virus, ''Toxoplasma gondii,'' herpes virus, and HIV
*[[Malformations]]
|
*[[Infections]]: Bacterial [[meningitis]], particularly from [[Streptococcus pneumoniae|''Streptococcus pneumoniae'',]] has been reported to be one of the most common postnatal causes of hearing loss in children.
*[[Traumatic brain injury|Traumatic]]


Sensory hearing loss (also called sensorineural hearing loss) may also result from abnormalities of the VIII cranial nerve.
*[[Autoimmune]]: Systemic diseases that cause hearing loss include [[Systemic lupus erythematosus CT|systemic lupus erythematosus]], [[rheumatoid arthritis]], [[myasthenia gravis]], and [[Hashimoto's thyroiditis]]


Sensory hearing loss that results from abnormalities of the central auditory system in the brain is called Central Hearing Impairment. Since the auditory pathways cross back and forth on both sides of the brain, deafness from a central cause is unusual.
*[[Neoplastic]]: Direct compression of the cochlear nerve by the [[tumor]], occlusion or vascular compression of the [[Internal auditory artery|internal auditory]] artery, intratumor bleeding, internal auditory channel occlusion, and [[toxic substances]] produced by the tumor that result in degeneration of the inner ear.
|}


Typical causes are discussed in following subsections.


==References==
==References==
{{reflist|2}}
{{Reflist|2}}
{{WH}}
 
{{WS}}
[[Category:Geriatrics]]
[[Category:Communication disorders]]
[[Category:Audiology]]
[[Category:Otolaryngology]]
[[Category:Noise pollution]]

Latest revision as of 09:17, 6 May 2021

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:

Overview

Classification is based on laterality, severity, cause, anatomy of ear, symmetry, clinical characteristics, age of onset, and associated symptoms.

Classification

Hearing losses can be classified according to:[1]

  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[2]
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 rely 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[3]
CONDUCTIVE SENSORINEURAL MIXED
CHL occurs when sound is not conducted efficiently through the outer ear canal to the middle ear due to any cause. 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 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: If SNHL takes hours or days to develop it can be due to:

If hearing loss develops in weeks:

If happens in years:

CLASSIFICATION BASED ON CAUSE[4][5]
CONGENITAL ACQUIRED
  • 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 result in degeneration of the inner ear.


References

  1. ↑ Nieman CL, Oh ES (2020). "Hearing Loss". Ann Intern Med. 173 (11): ITC81–ITC96. doi:10.7326/AITC202012010. PMID 33253610 Check |pmid= value (help).
  2. ↑ Nieman CL, Oh ES (2020). "Hearing Loss". Ann Intern Med. 173 (11): ITC81–ITC96. doi:10.7326/AITC202012010. PMID 33253610 Check |pmid= value (help).
  3. ↑ Kral A (2017). "[Pathophysiology of hearing loss : Classification and treatment options]". HNO. 65 (4): 290–297. doi:10.1007/s00106-016-0183-1. PMID 27299892.
  4. ↑ Kral A (2017). "[Pathophysiology of hearing loss : Classification and treatment options]". HNO. 65 (4): 290–297. doi:10.1007/s00106-016-0183-1. PMID 27299892.
  5. ↑ Kenna MA (2015). "Acquired Hearing Loss in Children". Otolaryngol Clin North Am. 48 (6): 933–53. doi:10.1016/j.otc.2015.07.011. PMID 26452421.
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