CSD 2230 HUMAN COMMUNICATION DISORDERS

1. CSD 2230HUMAN COMMUNICATION DISORDERS Audiology The Profession Acoustics Anatomy Hearing Loss and Pathologies Assessment and Treatment

2. The Profession of Audiology The discipline involved in: The prevention, identification, and evaluation of hearing disorders The selection and evaluation of amplification systems The habilitation/rehabilitation of individuals with hearing loss

3. What Kinds of Audiologists are There? Rehabilitative Audiologists Educational Audiologists Medical Audiologists Industrial Audiologists Audiologists in Private Practice University-Based Audiologists

4. Why Are Audiologists Important?? Hearing loss interferes with communication… Adults Consequences Children Consequences Video

5. The Hearing System

6. The Hearing System Basic schematic diagram of the entire auditory system

7. The Outer Ear Major Landmarks: • Pinna • External Auditory Meatus • Tympanic Membrane

8. Function of the Outer Ear • Collect and funnel sound to the eardrum • Protection • Resonance

9. The Middle Ear Major Landmarks: • Middle Ear Space • Eustachian Tube • Oval and Round Windows • Ossicles

10. Function of the Middle Ear • Amplifier and Transformer • Protection

11. The Inner Ear Major Landmarks: • Bony Labyrinth • Cochlea • Auditory and Vestibular Portions • Organ of Corti • Hair Cells

12. Central Auditory Pathways

13. Types of Hearing Impairment A loss of sensitivity Auditory nervous system pathology

14. Important Terms Time of onset • Congenital • Acquired • Adventitious

15. Important Terms Time Course • Acute • Chronic • Sudden • Gradual • Temporary • Permanent • Progressive • Fluctuating

16. Important Terms Number of Ears Involved • Unilateral • Bilateral

17. Hearing Sensitivity Loss • “The ear is not as sensitive as normal in detecting sound” • Types: • Conductive • Sensorineural • Mixed

18. Conductive Hearing Loss “Caused by an abnormal reduction or attenuation of sound as it travels from the outer ear to the cochlea”

19. Sensorineural Hearing Loss “Caused by a failure in the cochlea to transduce the sound from the middle ear to neural impulses in the VIII Nerve.”

20. Sensorineural Hearing Loss • Implications include: • A reduction in the sensitivity of the receptor cells in the cochlea • A reduction in the frequency resolving power of the cochlea • A reduction in the dynamic range of the system

21. Mixed Hearing Loss “A loss with both a conductive and sensorineural component.”

22. Auditory Nervous System Impairment Causes: • Disease • Disordered auditory nervous system development

23. Auditory Nervous System Impairment Kinds: • Retrocochlear disorders • Central auditory processing disorders

24. Auditory Nervous System Impairment • Auditory Characteristics: • Reduced ability to understand speech in a noise background • Problems understanding speech with reduced redundancy • Problems with localization and lateralization • Problems processing normal or altered temporal cues

25. Auditory Pathologies Outer and middle ear disorders • Conductive pathologies Cochlear disorders • Sensorineural pathologies Central auditory disorders • Central auditory pathologies

26. Outer and Middle Ear Disorders Structural defects due to embryologic malformations Structural changes secondary to infection or trauma

27. Microtia “an abnormal smallness of the auricle”

28. Atresia “the absence of an opening of the external canal”

29. Outer Ear Disorders Perforation of the tympanic membrane

30. Otitis Media Most common cause of transient conductive hearing loss in children Inflamation of the middle ear Caused by eustachian tube failure Middle Ear Disorders

31. Otitis Media Facts 76-95% of all kids will have one episode of OM by age 6 Prevalence is highest during the first two years of life 50% of all kids with one episode before their first birthday will have 6 or more bouts within two years Most episodes occur in winter and spring Risk factors Cleft palate Down syndrome Native Americans Urban poor Day care Secondhand smoke

32. Otosclerosis • “a bone disorder that affects the stapes and the bony labyrinth of the inner ear. The disease process is characterized by resorption of bone and new spongy formation around the stapes and oval window”

33. Otosclerosis • Facts: • Hereditary • Women are more likely to develop the disorder • Usually bilateral • Progressive

34. Cochlear Disorders Syndromes and inherited disorders Syndromic disorders Nonsyndromal disorders

35. Types of Nonsyndromic Disorders Dominant Dominant progressive Dominant progressive with adult onset Recessive hereditary SNHL X-linked

36. Noise Induced Hearing Loss • The degree of SNHL depends on • The intensity of the noise • The spectral composition of the noise • The duration of exposure • Individual susceptibility

37. Infections Congenital • Cytomegalovirus • HIV • Rubella • Syphilis • Toxoplasmosis

38. Infections Acquired • Herpes Zooster Oticus (Chicken Pox) • Mumps • Syphilis

39. Presbycusis Loss of hearing that gradually occurs in most individuals as they grow old. It is estimated that 40-50 percent of people 75 and older have some degree of hearing loss. It involves a progressive loss of hearing, beginning with high-frequency sounds such as speech. Presbycusis most often occurs in both ears, affecting them equally

40. Central Auditory Disorders VIII Nerve tumors Other diseases of the VIII Nerve Neural disorders Cochlear neuritis Diabetes mellitus Brain Stem disorders Infarcts Gliomas Multiple sclerosis Temporal Lobe disorders

41. Hearing Assessment Main questions • Is hearing normal? • What is the degree of hearing loss? • What type of hearing loss is it?

42. Hearing Assessment Procedures Behavioral Measures Measures of hearing behavior dependent on the perceptions and cooperation of the listener Nonbehavioral Measures Acoustic or physiological responses recorded in association with an acoustic event

43. Pure Tone Audiometry • Major behavioral auditory measure • Measurement of pure tone thresholds between 250-8000 Hz • Air conduction • Bone conduction

44. Pure Tone Audiometry The results of PTA tell us • Air conduction thresholds across frequency tells us if hearing is normal or not • If hearing by air conduction is NOT normal, the thresholds tell us the degree of hearing loss

45. Pure Tone Audiometry The results of PTA tell us • If hearing is normal or not • the degree of hearing loss • Differences between hearing by air conduction and hearing by bone conduction tell us the type of hearing loss

46. Air Conduction vs Bone Conduction Testing Air conduction tests the entire auditory system. Bone conduction bypasses the conductive mechanism, so it tests only the inner ear.

47. The Audiogram

48. What the Audiogram Says About the Impairment Within normal limits • Mild Moderate Severe Profound/deaf

49. Determining a Conductive Hearing Loss

50. Determining a Sensorineural Hearing Loss