1. Yard.Doc.Dr.Müzeyyen Doğan
HEARING LOSS
Yard.Doc.Dr.Müzeyyen Doğan

2. Learning goal and objectives of the lesson
Learning goal of the lesson: The learner should know the main clinical features and investigation of the hearing loss
Learning objectives of the lesson the learner will be able to:
expalin the type of hearing loss.
explain the acoustis trauma
list the indications of hearing aids.
explain the importance of early diagnosis of hearing loss and intervention

3. TYPES OF HEARING LOSS:
CONDUCTIVE
SENSORI-NEURAL
MIXED
NON-ORGANIC

4. CONDUCTIVE HEARING LOSS
Occurs from a dysfunction of the outer or middle ear
Can usually be treated with medicine or surgery
A deficit of loudness only

5. Characteristics of Conductive Loss:
Maintain soft speaking voice
Excellent speech discrimination when speech is loud enough
Typically either low frequency or flat hearing loss (equal at all frequencies)

6. CAUSES OF CONDUCTIVE HEARING LOSS: Outer Ear
Occlusion/foreign body
Congenital Atresia
External Otitis
Photo’s courtesy of Dr. Roy F. Sullivan, Ph.D.

7. Causes of Conductive Hearing Loss: Middle Ear
Otitis Media
TM Perforation
Cholesteatoma
Ossicular fixation
Otosclerosis
Ossicular Disarticulation
Blocked Eustachian Tube, reduced middle ear pressure, TM retraction and eventual effusion
Photo’s courtesy of Dr. Roy F. Sullivan, Ph.D.

8. TREATMENT: CONDUCTIVE HEARING LOSSES
Conductive hearing losses are due to problems that occur in the outer and middle ear which are usually temporary and/or treatable with antibiotics or surgery.
For those few people who have uncorrectable conductive hearing losses, hearing aids are of significant benefit as sound remains clear if it is made loud enough.

9. SENSORI-NEURAL HEARING LOSSES
Dysfunction of the inner ear or auditory nerve, usually permanent and untreatable
Results in loudness deficit and distorted hearing.
Nerve endings in cochlea or nerve pathways are damaged.
Message does not effectively reach the brain.
Middle ear structures are intact.

10. Characteristics of SNHL:
Inappropriately loud voice
Tinnitus
High frequency loss common, but any configuration possible
Speech sounds distorted
Background noise makes listening more difficult
Hearing aids may help

11. CAUSES OF SENSORI-NEURAL HEARING LOSS:
Genetics/Congenital
Disease
Mumps, Measles
Meningitis, CMV
Ototoxic drugs
Head trauma
Presbycusis
Meniere’s Disease
Acoustic Neuroma
Ototoxin Exposure
Noise Exposure:
Prolonged exposure to hazardous noise causes hearing loss by the physical destruction of the hair cells in the cochlea.

12. Characteristics of NIHL: (noise induced hearing loss)
Loss can be sudden, as with acoustic trauma from an explosion.
More often a gradual onset that may go unnoticed.
NIHL also known as noise induced permanent threshold shift (NIPTS), typically takes years of exposure, gradual erosion of hearing that eventually affects communication.

13. Characteristics of SNHL, con’t
Amount of loss varies from person to person
Risk of noise-induced progression stops if no longer in noise exposed, but aging invariably worsens loss
For most, aging effects aren’t significant before age 50+

14. Classic Symptoms of NIHL:
A notch or drop in hearing at 4000 Hz. Generally affects Hz range first, then notch becomes deeper & wider
Typically bilateral and symmetrical
Tinnitus common
Reduced speech comprehension, particularly in background noise. Why?
Vowels are low frequency sounds that carry 90% of speech energy (I can hear you talking….)
Consonants are higher frequency sounds that carry most of the meaning of speech. NIHL begins in high frequencies (But I can’t understand what you are saying.)

15. The “4 P’s” Noise induced hearing loss is: Painless Progressive
Permanent
Preventable
From Siemens Hearing Solutions

16. TREATMENT:
Sensori-neural hearing loss is due to problems that occur in the inner ear and are almost always permanent and untreatable.
Hearing aids will benefit most people with sensori-neural loss, but results can vary.

17. MIXED HEARING LOSS:
Combination of conductive (outer or middle ear) disorder and sensori-neural hearing loss.
Treatment may be available for the conductive portion; however, the sensori-neural portion will remain.
Causes can be unrelated (for example, NIHL plus TM rupture), or related (for example cochlear otosclerosis).

18. NON-ORGANIC HEARING LOSS
No medical or physical reason for hearing loss, may be voluntary or involuntary
Malingering:
Consciously faking or exaggerating a hearing impairment, often for monetary or other personal gain, to escape assignments or responsibilities, or as an anti-establishment gesture

19. NON-ORGANIC HEARING LOSS
Symptoms that should alert you to malingering:
Substantial, equal hearing loss at all frequencies or no response to pure tones at all in one or both ears
Inconsistent results, or markedly different than prior results
Unilateral “deafness” without significant medical history unlikely
Exaggerated attention to test, may press on earphones, difficulty hearing you call them back for testing or to your directions (normal voice level is around 60 dB), but can hear you when your back is turned or when no visual cues
Patient history may provide clues to non-organic behavior if nearing retirement, or pending discipline or deployment
Psychogenic Hearing Loss - Unconscious development of a non-organic hearing loss – a compensatory protective device, a psychogenic problem (the patient believes the impairment is real)

20. CENTRAL HEARING LOSS
Occurring within central nervous system (cortex, brainstem, or ascending auditory pathways) as opposed to peripheral organs of hearing (cochlea and middle ear)
Often associated with other neurological disorders (multiple sclerosis, tumors)
Sometimes confused with non-organic hearing loss due to vague symptoms or inappropriate test behavior
Always requires diagnostic work-up by an audiologist, otologist, and/or neurologist; patient usually hears WNL for pure tones

21. IN SUMMARY…. Conductive Hearing Loss: Sensori-neural Hearing Loss:
Usually low frequency or flat, affects outer and/or middle ear, usually temporary - or at least medically or surgically treatable.
Sensori-neural Hearing Loss:
Often high frequency, affects inner ear, usually permanent.
Mixed Hearing Loss:
Usually affects both high and low freqs, both conductive and sensori-neural components, but only conductive portion treatable.
Non-Organic Hearing Loss:
Typically display a flat loss or total deafness in one ear, but may exaggerate a true loss, may (rarely) be involuntary but usually malingering is involved. Prior test results are your best clue.
Central Hearing Loss:
Hearing for pure tones often normal, problem is between cochlea and cortex (receptor cells OK but a transmission or processing problem).

22. Questions?