Week 10 - Audiometry and SNHL Flashcards
Bone Anchored Hearing Aid
Client has conductive hearing loss
Inner ear functioning normally
Cochlear Implants
Client has both conductive and sensorineural hearing loss
Air Conduction Hearing Aid
Amplify and direct sound to the external acoustic meatus
For sensorineural hearing loss (not used for conductive)
Outer ear
Sound pressure waves are funneled by the pinna through the ear canal (external auditory meatus)
Pressure waves strike the tympanic membrane - causes vibrations
Use otoscope to assess
Middle ear
Eustachian tube connects with the nasopharynx, aerates the middle ear cavity and drains fluid
Blockages in ET = otitis media, build up of fluid, mild-to-moderate hearing loss
Inner Ear
Nerve cells inside the cochlea are arranged from lowest to highest pitch
Basal region - high-pitched sound info
Apical region - low-pitch sound info
Tympanometry
Testing the outer and middle ear
Objective test of the middle ear mobility or movement in response to a change in calibrated pressure
Gives info about volume of the ear canal, movement of ear drum and function of middle ear system
Shows if grommets are patent (not blocked), perforation in ear drum
Waardenburg Syndrome
70% of cases experienced bilateral sensorineural hearing loss
Pigment disturbances of hair, skin and iris
Usher Syndrome
Leading genetic cause of combined hearing and vision loss
Goldenhar Syndrome
Characterised by alterations involving the development of the structures of the first and second branchial branches
Affected face, eye, spine and ears
Auricular abnormalities are associated with hearing loss
Down Syndrome
Hearing loss
ME fluid accumulation
Prenatal Environmental Causes
Congenital rubella syndrome
Congenital syphilis
Cytomegalovirus
Foetal alcohol syndrome, other ototoxic agents
Perinatal Environmental Causes
Perinatal trauma (eg. forceps damage), infection, anoxia
Jaundice
Low birth weight
Preterm Birth Environmental Causes
Multiple factors - low birth weight, longer periods of oxygen treatment, medications
Post-Natal Environmental Causes
Prolonged administration, and/or higher doses of, oxotoxic drugs Infectious diseases: - Meningitis - Mumps - Measles - Encephalitis
Hearing Aid Considerations
Adjustment period - needs to be worn consistently Feedback - perceptions of loudness Family support Long term effects: - Increases risk of otitis media - Monitor middle ear
Hearing Aid Anatomy
Small pinna
BTE (behind the ear) difficult to attach, can be connected to assistive devices
ITC (in the canal) - small, choking risk
Growth - frequent need for new moulds
Cochlear Implants
Should benefit from CI
May be implanted in children or adults, with pre- or post-lingual deafness
Hearing with CI - differences between hearing with air conduction
Invasive - risks of surgery
Risk of failure of device
Cochlear Implants - Considerations
Amplification - test using the Modified Ling Test; incorporates all freq of sounds
Noise-Induced Hearing Loss
Excludes cases of acoustic trauma
Long-term occupational/social exposure
Gradual onset
Presbycusis
Age related degeneration Bilateral, progressive Onset from ~50 years of age More rapid for men than women 40% of western populations >75
Meniere’s Disease
Affects membranous inner ear; balance and hearing symptoms
Chronic, episodic
Vertigo with disequilibrium + horizontal rotatory nystagmus
Hearing loss (may be fluctuating)
Aural fullness and/or tinnitus
Familial trend
Head Trauma
Overt fracture of temporal bone - Cochlea fracture May co occur with conductive loss - Fracture of ossicles Tympanic membrane rupture Facial nerve may be affected
