1. Types of Hearing LossTypes of Hearing Loss
Heidi Walsh 2010Heidi Walsh 2010

2. Conductive Hearing LossConductive Hearing Loss
 Part of ear affectedPart of ear affected: outer and/or middle: outer and/or middle
 DescriptionDescription: occurs when sound cannot: occurs when sound cannot
reach inner ear – in other words whenreach inner ear – in other words when
something prevents sound from gettingsomething prevents sound from getting
into earinto ear

3. Outer Ear - CausesOuter Ear - Causes
 Blocked ear canalBlocked ear canal
WaxWax
Infection / swellingInfection / swelling
 Perforated eardrumPerforated eardrum
 Scarred / thickenedScarred / thickened
eardrumeardrum
Often caused by glueOften caused by glue
earear

4. Middle Ear - CausesMiddle Ear - Causes
 Broken ossiclesBroken ossicles
Hammer, anvil, stirrupHammer, anvil, stirrup
 Glue earGlue ear
Infection with build upInfection with build up
of sticky fluid whichof sticky fluid which
prevents ossicles fromprevents ossicles from
vibrating properlyvibrating properly

5. Middle Ear - CausesMiddle Ear - Causes
 Eustachian tube notEustachian tube not
opening and closingopening and closing
properlyproperly
Cold or catarrhCold or catarrh
Allergic reactionAllergic reaction

6. Middle Ear - CausesMiddle Ear - Causes
 OtosclerosisOtosclerosis
 Bony growth aroundBony growth around
base of stirrup whichbase of stirrup which
stops it from movingstops it from moving
properlyproperly
 Tends to run in familiesTends to run in families
 Often triggered byOften triggered by
pregnancy in womenpregnancy in women

7. Sensori-neural Hearing LossSensori-neural Hearing Loss
 Part of ear affectedPart of ear affected: inner ear and/or: inner ear and/or
auditory nerveauditory nerve
80% of people with a hearing loss have SNHL80% of people with a hearing loss have SNHL
 DescriptionDescription: occurs when either the hair: occurs when either the hair
cells in the cochlea and/or the nerve to thecells in the cochlea and/or the nerve to the
brain are damaged and sound is not beenbrain are damaged and sound is not been
passed onto the auditory centre in thepassed onto the auditory centre in the
brainbrain
 Very rare that the exact cause can beVery rare that the exact cause can be
identifiedidentified

8. The Inner EarThe Inner Ear
Cochlea
Auditory nerve

9. Inner Ear - CausesInner Ear - Causes
 Commonest cause – old age deafnessCommonest cause – old age deafness
(presbyacusis)(presbyacusis)
 Noise damageNoise damage
 Virus or infectionVirus or infection
 High doses of some medicationsHigh doses of some medications
 Chemotherapy / radiotherapy –Chemotherapy / radiotherapy –
sometimessometimes

10. Inner Ear - CausesInner Ear - Causes
 Acoustic neuroma (benign tumour)Acoustic neuroma (benign tumour)
 Accident – head injuryAccident – head injury
 Autoimmune Inner Ear Disease (AIED)Autoimmune Inner Ear Disease (AIED)
 Meniere’s DiseaseMeniere’s Disease
 CongenitalCongenital

11. Mixed Hearing LossMixed Hearing Loss
 Part of ear affectedPart of ear affected: Outer/middle and: Outer/middle and
innerinner
 DescriptionDescription: combination of both types of: combination of both types of
hearing loss described previouslyhearing loss described previously
 CausesCauses: generally more than one cause –: generally more than one cause –
or conductive loss plus age-relatedor conductive loss plus age-related
hearing losshearing loss

12. Central Auditory ProcessingCentral Auditory Processing
Disorder (CAPD)Disorder (CAPD)
 Part of ear affectedPart of ear affected: none: none
Caused by a difficulty in the hearing part ofCaused by a difficulty in the hearing part of
the brainthe brain
 DescriptionDescription: occurs when sound reaches: occurs when sound reaches
brain but there is a delay / difficulty inbrain but there is a delay / difficulty in
identifying sound patternsidentifying sound patterns
a sort of hearing dyslexiaa sort of hearing dyslexia
can be helped by lipreading as ability tocan be helped by lipreading as ability to
process words is not affectedprocess words is not affected

13. More InformationMore Information
 RNID websiteRNID website
 http://www.rnid.org.uk/information_resources/ahttp://www.rnid.org.uk/information_resources/a
Includes factsheets & videosIncludes factsheets & videos