Nature & Etiology of Hearing Loss

Question 1

3-4 months- development

Answer 1

Babies will turn their head to sound & respond to their mothers voice more than anything else

Question 2

6 months

Answer 2

infants can localize soft speech normal hearing babies at this age have better hearing than adults

Question 3

air cionduction

Answer 3

when sound is carried through the medium of air:
sound that hit the TM –> causes ossicles to move –> causes fluids of the inner ear to move –> movement causes vibrations of the basilar membrane –> hair cells supplied by the acoustic nerve respond to the vibrations & carried to the brain via electric impulses

Question 4

bone conduction

Answer 4

the larger bones of the skull conduct the sounds as well as the ossicles. the bones vibrate in response to airborne sound waves causing the inner ear fluids to vibrate

Question 5

Risk factors for hearing loss

Answer 5

anatomic malformations in the face/ head/ neck, maternal history of alcohol/ drug use, certain maternal diseases like rubella or syphilis during pregnancy, genetic predispositions

Question 6

Slight Hearing loss

Answer 6

16-25 dB HL

Question 7

Mild Hearing Loss

Answer 7

26-40 dB HL

Question 8

Moderate Hearing Loss

Answer 8

41-55 dB HL

Question 9

Moderately Sever Hearing Loss

Answer 9

56-70 dB HL

Question 10

Severe Hearing Loss

Answer 10

71-90 dB HL

Question 11

Profound Hearing Loss

Answer 11

91+ dB HL

Question 12

Deaf

Answer 12

Children/Adults cannot hear conversational speech under normal circumstances

Question 13

Conductive Hearing Loss

Answer 13

• damage to the middle ear leading to impaired ability to conduct sound- pure conductive hearing loss means inner ear, acoustic nerve, and auditory centers of the brain are all working normally
• CONDUCTIVE HEARING LOSS IS NEVER PROFOUND EVEN WHEN OSSICLES ARE NOT WORKING BECAUSE SKULL BONES CAN STILL CONDUCT SOUND
• PEOPLE WITH CONDUCTIVE HEARING LOSS WILL TYPICALLY SPEAK SOFTLY BECAUSE THEY CAN HEAR THEMSELVES

Question 14

Causes Conductive Hearing Loss

Answer 14

abnormalities in the EAM, TM, or ossicular chain in middle ear, birth defects, diseases, foreign bodies, bony growths, tumors, otosclerosis

Question 15

Aural Atresia

Answer 15

external ear canal in completely closed. commonly associated with microtia which is a small/deformed pinna.

Question 16

Stenosis

Answer 16

results in extremely narrow EAC- most sound waves will not strike the TM

Question 17

External Otitis

Answer 17

infection of the skin of the external auditory canal which causes swelling, sound transmission is reduced

Question 18

Otitis Media

Answer 18

aka middle ear effusion an ear infection if the middle ear often associated with upper respiratory infection and eustachian tube dysfunction
-typically causes a conductive hearing loss of 20-35 dB HL

Question 19

Otosclerosis

Answer 19

condition characterized by new spongy growth in the stapes footplate causing the stapes to become rigid which means the footplate cannot go into the oval window enough to create necessary pressure waves

Question 20

Carthart’s Notch

Answer 20

telltale sign of otosclerosis in an audiogram characterized by reduced bone-conduction sensitivity predominantly at 2000 Hz

Question 21

Sensorineural Hearing Loss

Answer 21

damage to the hair cells of the cochlea (sensori) or the acoustic nerve (neutral) prevents the brain from receiving the neural impulses of the sound which causes PERMANENT damage because those pieces cannot be repaired

• People with this type of hearing loss will speak LOUDLY because there is air and bone conduction loss so they cannot hear themselves
• higher frequencies tend to be more effected than lower frequencies

Question 22

STORCH

Answer 22

acronym for the major causes of hearing loss in fetuses
Syphilis
Toxoplamosis- disease transmitted through the placenta when mother contacts cat feces or raw eggs/meat
Rubella- German measles
Cytomegalovirus- herpes-type virus is the most common cause of viral hearing loss
Herpes Simplex- transmitted from mother to fetus

Question 23

Acoustic Neuroma

Answer 23

tumor that can develop on the acoustic nerve and cause sensorineural hearing loss by slowing down nerve conduction of sound impulses to brain

Question 24

Presbycusis

Answer 24

“old ears” sensorineural type hearing loss associated with normal aging

Question 25

Meniere’s disease

Answer 25

disease that causes fluctuating hearing loss in normally typical adults
-caused by excessive endolymphic fluid pressure in the membranous labyrinth which causes Reissner’s membrane to become distended

Question 26

Mixed Hearing Loss

Answer 26

the middle and the inner ear are not functioning properly caused by any combination of the sensorineural and conductive hearing losses

Question 27

Central Auditory Processing

Answer 27

the effectiveness and efficiency with which the central nervous system processes auditory information
-difficulty taking spoken information and ad interpreting it to make it meaningful

Question 28

Peripheral Hearing Problems

Answer 28

result from problems in the outer, middle, or inner ear (excluding the auditory nerve)

Question 29

Central Auditory Disorders

Answer 29

refers to hearing losses due to disrupted sound transmission between the brainstem and the cerebrum as a result of damage/malformation
- the temporal cortex may receive incorrect information OR the person may process information incorrectly

Question 30

Causes CAP disorders

Answer 30

tumors, TBI, HIV, asphyxia during birth, genetic disorders, infections like meningitis, metabolic disturbances, cerebrovascular disorders, drug/chemical induces disorders, Alzheimer’s disease, multiple sclerosis or other demyelinating diseases

Question 31

Testing for CAPD

Answer 31

people with CAPD do not have significant peripheral hearing loss. they may do well on speech recognition tests in quiet environments and in pure tone audiometry

Question 32

Dichotic testing

Answer 32

listener must decipher a a different message in each are presented simultaneously- CAPD patients will have a lot of difficulty with this

Question 33

Retrocochlear Disorders

Answer 33

damage to the nerve fibers along the ascending auditory pathways from the internal auditory meatus to the cortex

• typically consist of pathology involving the cerebellopontine angle or cranial nerve VIII
• typically caused by unilateral tumors (acoustic neuromas) audiogram shows unilateral high frequency hearing loss
• typically accompanied by alterations in facial sensation and movement because of facial and trigeminal nerve involvement- possible headache in ear region