This document discusses deafness and hearing loss. It defines different types and degrees of hearing loss. Conductive hearing loss occurs when sound is not conducted properly through the outer or middle ear. Sensorineural hearing loss occurs due to damage to the inner ear or auditory nerve. Mixed hearing loss has both conductive and sensorineural components. Rehabilitation methods are described including hearing aids, bone anchored hearing aids, cochlear implants, and auditory brainstem implants. Types of hearing aids and how they work are explained. Speech reading, auditory training, and education of the deaf are important rehabilitation strategies. The overall message is that untreated hearing loss is more noticeable than using hearing aids or other assistive devices.

1. Deafness
Dr. Jairaj Vaishnav
SR in ENT
SMS Hospital

2. “When you lose your vision, you lose
contact with things; when you lose your
hearing, you lose contact with people.”
Helen Keller

3. Protection
Impedance
match
Capture; Amplify mid-freqs
Vertical direction coding
Frequency
analysis
Transduction
Outer, middle & inner ear

4. ICF Defination (WHO:
2001DDD)
Hearing impairment :refers to complete or partial
loss of the ability to hear from one or both ears.
The level of impairment can be mild, moderate,
severe or profound;
Deafness : refers to the complete loss of ability to
hear from one or both ears.

5. Type of Loss
 Conductive
 Sensorineural
 Mixed
 Auditory Processing
Disorder

6. Quantification of Hearing Loss
 Unable to hear sound at
 “Mild” Hearing Loss
 26 – 40 dB
 “Moderate” Hearing Loss
 41-55 dB
 “Severe” Hearing Loss
 56- 70 dB
 “Profound” Hearing Loss
 91 dB & greater

7. Degree of Hearing Loss
 Minimal
 Mild
 Moderate
 Moderately Severe
 Severe
 Profound

8. Impact of HL on Quality of Life
 Physical health
 Emotional & mental health
 Other’s perceptions of a person’s mental acuity
 Social skills
 Family relationships
 Self-esteem
 Work & school performance

9. Hearing Loss
 Part of ear not working
 Includes:
 outer ear
 middle ear
 inner ear
 hearing acoustic nerve
 auditory system

10. Types
 Conductive deafness: due to defect in the
conducting mechanism of the ear namely external
and middle ear.
 Sensori-neural deafness / Perceptive deafness:
due to lesions in the labyrinth, 8th
nerve & central
connections. It includes psychogenic deafness.
 Mixed deafness: both the above mentioned types
are present.

11. External ear:
 Wax,
 Fungus,
 Otitis Externa,
 Foreign Bodies,
 Polyps,
 Myringitis,
 Stenosis,
 Atresia,
 Tumours.
Causes of Conductive deafness

12. Middle Ear
Cont…..
 Congenital defects of
the ear drum and
ossicles.
 Traumatic: Barotrauma,
rupture of ear drum, #
of the base of the skull
 Inflammation: AOM,
COM, Serous OM,
Adhesive OM.
 Tuberculosis and
syphilitic OM
 Neoplasms
 Otosclerosis

13. Causes of Conductive deafness
Eustachian tube Catarrh = xcessive discharge
from nose / throat / ear
 Eustachian catarrh
 Eustachian tube
dysfunction due to
diseases of the nose,
paranasal sinuses &
pharynx
 Barotrauma

14. Conductive Sensorineural

15. Causes of Sensori-neural deafness
Local causes (inner ear)
 Congenital
 Trauma: Head injury,
surgical injury to labyrinth,
loud sounds (acute or
chronic acoustic trauma)
producing concussion.
 Infections: mumps,
syphilis, tuberculous
meningitis, enteric fever,
labyrinthitis.
 Tumours: Acoustic
neuroma (Schwanoma of
C8 nerve)
 Meniere’s disease
 Ototoxic drugs:
streptomycin, Kanamycin,
neomycin, salicylates,
frusemide and quinine.

16. Causes of Sensori-neural deafness
General causes
 Presbycusis
 CVS: atherosclerosis, HTN
 CNS: disseminated
sclerosis
 DM
 Avitaminosis
 Hypothyroidism
 Smoking
 Alcoholism
 Presbyacusis: is a
progressive bilateral
symmetrical age-related
sensorineural hearing loss.
It is also known as age-
related hearing loss

17. Causes of Sensory-neural deafness
Psychogenic deafness: 2 types
 Functional: due to
emotional cause, but the
patient is not aware of the
cause.
 Malingering: no organic or
psychological cause.The
patient is aware that he is
pretending to be deaf for
personal gains.

18.  Trauma: Blast injury, acoustic trauma, head
injury.
 CSOM with labyrinthitis.
 Otosclerosis
 Senile deafness superimposed on conductive
deafness.
Causes of Mixed deafness

19. “The assessment, intervention, and management of
communicative consequences of hearing loss”
Rehabilitation

20. Methods of rehabilitation
I. Instrumental devices
A. Hearing Aids
- Conventional hearing aids
- Bone anchored hearing aids
- Implantable hearing aids
B. Implants
- Cochlear implants
- Auditory brainstem implants
C. Assistive devices for the deaf
II. Training
A. Speech(lip) training
B. Auditory training
C. Speech conservation

21. Hearing aids
Device to amplify sounds ---- 3 parts.
 Microphone- picks up sound and converts to electrical impulses.
 Amplifier- magnifies electrical impulses.
 Receiver-converts electrical impulses back to sound.
Types
Air conduction hearing aids
Bone conduction hearing aids

22. Hearing Aids
 Body worn types
 Behind the ear types
 Spectacles type
 In the ear type
 Canal types(ITC/CIC)
Types

23. Types of hearing aids

24. Bone anchored hearing aids
 Based on the principle of bone conduction
 Candidacy profile
a) chronic inflammation or infection of ear canal
b) children with malformed or absent outer canals
c) unilateral deafness.

25. Bone anchored hearing aids
Titanium fixture, abutment, sound processor

26. Bone anchored hearing aids
When air conduction hearing aid can’t be used
- Canal atresia
- Chronic ear discharge
- Excessive feedback and discomfort
CoHL / Mixed hearing loss
- otosclerosis / tympanosclerosis.
Single sided hearing loss
Indications for BAHA

27. Implantable hearing aids
Mechanical vibration delivered directly to the ossicular chain
2 types
1) piezoelectric devices
2) electromagnetic hearing devices
.
Candidacy profile
- Adults 18 yrs and older with moderate to severe SNHL
- Should have an experience with hearing aids previously

28. Implantable hearing aids
Vibrant soundbridge device
Semi implantable device made of 2 components

29. Cochlear implants
Electronic device- electrical stimulation of auditory nerve
2 components external- sound processor, mic, transmitter and
internal-receiver/stimulator, electrode array

30. Auditory brainstem implant
 Stimulates the cochlear nuclear complex in the brainstem directly by
placing the implant in the lateral recess of the fourth ventricle.
 Used when CN VIII is severed in the surgery of vestibular schwannoma
 Multi electrode array is attached to a decron mesh which is placed on
the brainstem

31. Auditory brainstem implant

32. Definition
 Cochlear implants are surgically placed
electrical device that receive sound and
transmit the resulting electrical signals to
electrodes implanted in the cochlea of the
ear.
 The signals stimulate cochlea, allowing
patient to hear.
 It is also known as Bionic ear.

33. Parts of cochlear implant
 External
 Microphone
 Speech processor
 Transmitter
 Internal
 Receiver and stimulator
 An array of up to 22 electrodes

36. Mechanism
 Cochlear implants bypass damaged portion
of the ear & directly stimulate the auditory
nerve and later the brain recognizes it as
sound.

37. Assistive devices
Helps in special difficult situations
Warns of danger signals
3 groups
1. Assistive listening devices and systems
2. Alerting devices
3. Telecommunication devices
Training
1. Speech reading
2. Auditory training
3. Speech conservation

38. Management of rehabilitation
 Parental guidance
 Hearing aids
 Speech & language therapy
 Education of the deaf
 Vocational guidance

39. ? How a cochlear implant works.webm

40. "An
untreated
hearing loss
is more
noticeable
than
hearing
aids."

41. Thank you for “LISTENING”