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Presented by Coleen Maritz Audiologist

AUDIOLOGY. Presented by Coleen Maritz Audiologist. 1. Anatomy of the ear. 2. Types of Hearing Loss. Conductive Hearing Loss - Resultant of outer or middle ear pathology. When the transmission of sound is interrupted in the outer ear or more frequently in the middle ear.

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Presented by Coleen Maritz Audiologist

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  1. AUDIOLOGY Presented by Coleen Maritz Audiologist

  2. 1. Anatomy of the ear

  3. 2. Types of Hearing Loss • Conductive Hearing Loss - Resultant of outer or middle ear pathology. When the transmission of sound is interrupted in the outer ear or more frequently in the middle ear. - Children: most common cause is otits media. Adults: most common cause is otosclerosis.

  4. Types of Hearing Loss Cont. • Sensorineural Hearing Loss - Resultant of inner ear and/or auditory nerve damage. - When the hair cells of the cochlea or the acoustic nerve are damaged.

  5. Types of Hearing Loss Cont. • Mixed Hearing Loss - Involves a combination of a conductive and sensorineural hearing loss.

  6. 3. Causes of Hearing Loss • Causes of Conductive Hearing Loss • Outer and middle ear disorders may cause a conductive hearing loss.

  7. Outer & Middle Ear Disorders

  8. Outer & Middle Ear Disorders Cont

  9. Outer & Middle Ear Disorders Cont

  10. Outer & Middle Ear Disorders Cont

  11. Outer & Middle Ear Disorders Cont

  12. Causes of Hearing Loss Cont. • Causes of Sensorineural Hearing Loss 1. Prenatal Congenital infections * CMV – viral infection; type of herpes virus transmitted in utero; can cause hearing loss, blindness and seizures * HIV – affinity for CNS; opportunistic infections cause hearing loss eg. Meningitis * Rubella – viral infection

  13. Causes of Hearing Loss Cont. * Syphilis – often causes progressive hearing loss; onset after 2 years of age * Toxoplasmosis – caused by parasite infection transmitted through contaminated food; causes hydrocephalus, mental retardation and hearing loss

  14. Causes of Hearing Loss Cont. 2.Perinatal Causes • Hypoxia • Birth trauma • Hyperbilirubenemia • Ototoxic medication • Premature infants = increased risk for hearing loss

  15. Causes of Hearing Loss Cont. 3. Acquired hearing loss • Herpes zoster oticus (Ramsay Hunt Syndrome) – same virus that causes chickenpox; can cause hearing loss • Mumps – acute systemic viral disease; common in childhood over the age of 2 years; often causes unilateral hearing loss • Measles • Meningitis • Serous labyrinthitis (inflammation of labyrinth)

  16. Causes of Hearing Loss Cont. • Ototoxic medication: [Oto=ear. Ototoxic=Toxic to the ear] Ototoxic medications are drugs that have the potential to cause damage to the inner ear structures which may result in temporary or permanent hearing loss or an aggravation of an existing sensorineural hearing loss. Consuming more than one ototoxic medication at a time increases your risk to develop a sensorineural hearing loss.

  17. Causes of Hearing Loss Cont. 1. Aminoglycosides (antibiotics): • Amikacin • Gentamycin • Garamycin • Kanamycin • Netilmycin • Tobramycin • Streptomycin • Viomycin • Neomycin

  18. Causes of Hearing Loss Cont. • Aminoglycosides (antibiotics) cont: These medications are toxic when used intravenously in serious life threathening situations. The blood levels of these medications are usually monitored to prevent ototoxicity. Topical preparations and ear drops containing these antibiotics, Neomycin, Gentamycin, have not been demonstrated to be toxic in humans.

  19. Causes of Hearing Loss Cont. 2. Erythromycin (antibiotics): • EES • Eryc • E-mycin • Ilosone • Pediazole • Biaxin • Zithromax New derivatives of Erythromycin

  20. Causes of Hearing Loss Cont. • Erythromycin (antibiotics) cont: These are usually ototoxic when given intravenously in dosages of 2-4 grams per 24hours, especially if there is underlying kidney insufficiency. The usual oral dosage of one gram per 24hours is not toxic. There are no significant reports of ototoxicity with new Erythromycin derivatives, since they are given orally at lower dosages.

  21. Causes of Hearing Loss Cont. 3. Vancomycin – Vancocin (antibiotics) This antibiotic is used in a similar manner as the aminoglycosides; when given intravenously in serious life-threatening infections. It is potentially ototoxic. It is usually used together with the aminoglycosides which enhances the possibility of ototoxicity.

  22. Causes of Hearing Loss Cont. 4. Salicylates (used in treatment of arthritis): Toxic effects usually appear after consuming an average of 6-8 pills per day. Toxic effects are reversible once medication is discontinued. • Acetylsalicylic acid • Aspirin

  23. Causes of Hearing Loss Cont. 5. Antimalarial medication-Quinine Derivitaves: Quinine ingestion can cause a syndrome including tinnitus, sensorineural hearing loss and vertigo. Recent studies suggest that quinine impairs outer hair cell mobility. Ototoxic effects are similar to asprin- reversible once medication is discontinued).

  24. Causes of Hearing Loss Cont. Antimalarial medication-Quinine Derivitaves (cont.): • Quinidex (causes tinnitus) • Atrabrine • Plaquenil • Quinine Sulfate • Mefloquine • Chloroquine

  25. Causes of Hearing Loss Cont. 6. Loop diuretics: These medications are usually ototoxic when given intravenously for acute kidney failure or acute hypertension. Rare cases have been reported when these medications are taken orally in high doses in people with chronic kidney disease. • Edecrin (Ethacrynic acid) • Lasix (Furosemide) • Bumex (Bumetanide)

  26. Causes of Hearing Loss Cont. 7. Chemotherapeutic Agents: • Ciaplatin • Nitrogen Mustard • Vincristine These medications are ototoxic when given for treatment of cancer. The ototoxic effects of these medications are enhanced in patients who are already taking other ototoxic medications.

  27. Causes of Hearing Loss Cont. 8. Nonsteroidal Anti-Inflammatory Drugs Toxic effects usually appear after consuming an average of 6-8 pills per day. Toxic effects are usually reversible once medications are discontinued. • Advil Motrin • Aleve Nalfon • Anaprox Naprosyn • Clinoril Nuprin • Feldene Poradol • LodineVoltarin

  28. Causes of Hearing Loss Cont. • Acoustic trauma – temporary or permanent • Ménière’s disease – causes vertigo, hearing loss, tinnitus, pressure in ear; can be unilateral, fluctuating or progressive • Presbyacusis – age related sensorineural hearing loss • Noise exposure- most common cause of HL.

  29. Causes of Hearing Loss Cont. • Noise Exposure- Damage risk criteria expressed as the maximum permissible noise exposure for a given duration during a work day.

  30. Causes of Hearing Loss Cont.Syndromes associated with Auditory DysfunctionSee handout

  31. 4. Prevalence of hearing loss • 3/1000 infants are born with congenital severe bilateral hearing loss • Additional 3 children acquire hearing loss early in childhood • Hearing loss occurs twice as frequently as other congenital abnormalities screened for in newborns combined: congenital hypothyroidism; sickle cell anemia; phenylketonuria; galactosemia • Prevalence = 10-20 times higher in NICU

  32. Prevalence of hearing loss cont. • Prevalence in general population: • 2/1000 = severe-profound HL • 5/1000 = moderate-severe HL • 8/1000 = mild HL • 150/1000 = middle ear infections • Prevalence expected to be even higher with increase in HIV/AIDS infection

  33. 5. Tinnitus 1. Definition of tinnitus: • “…hearing a sound that is not related to any external sound in the environment” • Ringing sound in patient’s ears is generated by patient’s own body, and is not present in external environment • Most common types of sounds reported by patients: ringing, hissing, buzzing, cricket sounds

  34. Tinnitus cont. 2. Neurophysiological model of Tinnitus Stages of tinnitus emergence: • Generation- typically in the periphery • Detection – subcortical centers • Perception and evaluation – cotical areas • Sustained activation of emotional (Limbic) and autonomic nervous systems

  35. Tinnitus cont. 3. Prevalence of tinnitus • 17% of general population (44million) • Clinically significant problems for approximately 4-5% of the population 4. Impact on patients’ lives • Ranges from mild irritation to total disability, and in some cases suicide

  36. Tinnitus cont. 5. Causes • May be associated with sensorineural hearing loss (damage to OHC and IHC) • Ionic imbalance in the cochlea • Dysfunction of cochlear neurotransmitter systems • Central • Certain medication may cause tinnitus: eg. antidepressants, benzodiazeptines • Unknown causes in a lot of cases

  37. Tinnitus cont. 6. Treatment • Unable to suppress tinnitus source – therefore do not currently have a cure • Tinnitus Retraining Therapy – helps patients to adapt to noise, and to change their brain’s perception of the tinnitus; makes use of noise generators to mask tinnitus • Success rate of 80%

  38. 6. Hearing Tests • 1. Audiometry • Puretone • Speech • 2. Immittance Testing • Tympanometry • Acoustic Reflexes • 3. Electrophysiological Testing • Otoacoustic Emissions (OAE) • Auditory Brainstem Response (ABR)

  39. Hearing Tests cont. • 1. Audiometry • 1.1 What is audiometry & how does it work? • 2 measures: intensity & frequency • Intensity: • Loudness, measured in dB • Human ear: 0-120 dB • Frequency: • Pitch/ tone of sound, measured in Hz • Human ear: 20-20 000Hz; 125-8000 Hz

  40. Hearing Tests cont. • Air conduction audiometry: • Earphones, outer ear, middle ear, inner ear, n. VIII • Bone conduction audiometry: • Bone conductor on mastoid

  41. Hearing Tests cont. • 1.2 Aims of Audiometry: • Measure degree of HL: minimal, mild, moderate, severe, profound • Measure site of lesion in hearing mechanism • Determine cause of HL • Determine degree of handicap (how HL affects patient’s activities of daily life)

  42. Hearing Tests cont. • 1.2 Aims of Audiometry cont: • Obtain indications for appropriate therapeutic and educational assistance – hearing aids; assistive listening devices; speech-language therapy; school placement

  43. Degree of Hearing Loss

  44. Environmental sounds measured on audiogram

  45. What is an Audiogram? • An AUDIOGRAM is a graphic representation of a hearing test.

  46. Normal Hearing

  47. 7. Types of Hearing Loss-Audiogram • 1. Conductive hearing loss • Resultant of external or middle ear pathology • Air conduction abnormal • Bone conduction normal

  48. Conductive Hearing Loss

  49. Types of Hearing Loss-Audiogram cont. • 2. Sensorineural hearing loss • Resultant of inner ear and/or auditory nerve damage • Air conduction and bone conduction equally abnormal

  50. Sensori-neural Hearing Loss

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