1. CSD 2230 HUMAN 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. Sound System Source  Any vibrating object Medium  Any gas, liquid or solid Receiver  Anything designed to detect the vibrations within the medium originating from the source

6. A Common Sound System Illustration of the distribution of molecules surrounding a source in an instant in time

7. Condensation and Rarefaction Bands of condensation and rarefaction emanating from a sound source

8. Important Physical Characteristics of Sound Frequency Rate of pressure change as a function of time Measured as cycles/sec or Hertz The primary determiner of pitch Intensity Magnitude of the pressure change Measured as the decibel (dB) The primary determiner of loudness

9. The Hearing System

10. Basic schematic diagram of the entire auditory system

11. The Outer Ear Major Landmarks: 1. Pinna 2. External Auditory Meatus 3. Tympanic Membrane

12. Function of the Outer Ear 1. Collect and funnel sound to the eardrum 2. Protection 3. Resonance

13. The Middle Ear Major Landmarks: 1. Middle Ear Space 2. Eustachian Tube 3. Oval and Round Windows 4. Ossicles

14. Function of the Middle Ear 1. Amplifier and Transformer 2. Protection

15. The Inner Ear Major Landmarks: 1. Bony Labyrinth 2. Cochlea 3. Auditory and Vestibular Portions 4. Organ of Corti 5. Hair Cells

16. Central Auditory Pathways

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

18. Important Terms Time of onset Congenital Acquired Adventitious

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

20. Important Terms Number of Ears Involved Unilateral Bilateral

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

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

23. 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.”

24. Sensorineural Hearing Loss n 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

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

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

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

28. 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

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

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

31. Microtia “an abnormal smallness of the auricle”

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

33. Outer Ear Disorders Perforation of the tympanic membrane

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

35. 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

36. Otosclerosis n “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”

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

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

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

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

41. Infections Congenital  Cytomegalovirus  HIV  Rubella  Syphilis  Toxoplasmosis

42. Infections Acquired  Herpes Zooster Oticus (Chicken Pox)  Mumps  Syphilis

43. 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

44. 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

45. Hearing Assessment Main questions 1. Is hearing normal? 2. What is the degree of hearing loss? 3. What type of hearing loss is it?

46. 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

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

48. Pure Tone Audiometry The results of PTA tell us 1. Air conduction thresholds across frequency tells us if hearing is normal or not 2. If hearing by air conduction is NOT normal, the thresholds tell us the degree of hearing loss

49. Pure Tone Audiometry The results of PTA tell us 1. If hearing is normal or not 2. the degree of hearing loss 3. Differences between hearing by air conduction and hearing by bone conduction tell us the type of hearing loss

50. 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.

51. The Audiogram

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

54. Determining a Conductive Hearing Loss

55. Determining a Sensorineural Hearing Loss

56. Determining a Mixed Hearing Loss

57. Speech Audiometry Another behavioral measure of auditory ability Speech thresholds Speech Reception threshold Speech Awareness threshold Word recognition testing

58. Identifying Hearing Loss Through the First Year Communication checklists Parents’ reports Case history Informal observation Formal testing Visual Reinforcement Audiometry Behavioral Observation Audiometry

59. Typical Response Levels to Sounds from Birth-2 years

60. Nonbehavioral Measures of Hearing Auditory brainstem evoked response (ABER)

61. Nonbehavioral Measures of Hearing Otoacoustic Emissions

62. Treatment Medical Most conductive hearing losses, caused by pathologies in the outer and/or middle ear, can be treated successfully by medication and/or surgery

63. Treatment Amplification Hearing aids are the most common treatment of sensorineural hearing loss Hearing aids amplify speech and other sounds They work best for people with mild through severe degrees of hearing loss

64. Treatment Cochlear Implants Used for children and adults who are deaf These devices stimulate the auditory nerve directly They are best for people who get very little benefit from conventional hearing aids

65. Treatment Habilitation/Rehabilitation Auditory Training Children and adults Communication Strategies Speechreading, noise management, assertiveness training Communication Methods Sign language, cued speech Counseling