ways to assess whether a person hears normally or not right from very basic upto advanced by Dr zeeshan ahmad presented in ENT NMCH patna on 10-02-11

2. ASSESSMENT OF HEARING by:- Dr ZEESHAN AHMAD NMCH PATNA INDIA

4. Pathways for air and bone conduction

6. A uditory cortex M GB I nferior collliculus L ateral lemniscus O livary nucleus(superior) C ochlear nucleus E ight cranial nerve E.COLI-MA PL Dhingra has simplified auditory pathway and made it easier to remember by a mnemonic

7. Tuning Fork Tests

13. Various positions of tuning fork during tuning fork tests On mastoid At the opening of EAC Midline of skull

25. Pure Tone Audiometry

26. Pure Tone Audiometry -Audiometer is an electronic device which produces PURE TONES ,the intensity of which can be increased or decreased by 5dB steps -Air conduction thresholds are measured from 125 to 8000 Hz -Bone conduction thresholds from 250 to 4000 Hz -The intensity of sound to be raised above normal to make it hear is a measure of degree of hearing impairment -This is charted on a graph called AUDIOGRAM

27. Those mysterious markings

28. Legends for PTA’s

29. Air conduction Bone conduction

32. It’s a Normal PTA Sensorineuronal/conductive abnormality ??

34. Hearing Loss Table Classification PTA Profound hearing loss >90 Severe HL 71-90 Moderately severe HL 61-70 Moderate HL 41-60 Mild hearing loss 21-40 Normal 0-20

36. Conductive Loss What’s this shows

37. Sensorineural Loss

38. Mixed Loss Now what does this one shows

42. Speech Audiometry

44. Imepedence Audiometry (Tympanometry + stapedial reflex)

45. Tympanometry

48. Tympanometry Janet Stockard Sullivan 2003

49. Here’s how it works...

50. These 5 second motion video otomacroscopy (MVOM) samples resent a view of a 58 year male right tympanic membrane during tympanometry. The patulous pars flaccida was ejected at the outset of recording from a prior tympanometric trial. The Middle Ear Analyzer was set to run from +400 daPa though -600 daPa. MVOM and tympanograms were video-captured 15 f/s . The time lines between videos are only roughly coincident. The negative slope of the tympanogram corresponds to the period of rapid pars flaccida ejection.

51. videos Taken from--- http:// www.rcsullivan.com/www/tympavi.htm

61. OTOACOUSTIC EMISSIONS

64. OAE’s spontaneous evoked Transient (click) Distortion product (paired tones)

67. Distortion Product OTOACOUSTIC EMISSIONS

69. Brainstem Evoked Response Audiometry (BERA)

70. BERA Brainstem Evoked Response Audiometry

73. Cochlear nerves Cochlear nucleus Superior olivary complex Nulclei of lateral lemniscus Inferior colliculus

77. A COMPARISON Unsuitable for children Suitable for even young children Response begins after 50 - 300 milliseconds after stimulation Responses begin after 1 - 10 milliseconds after stimuli The patient must lie still through out the process Can be performed in awake and restless patients Responses are frequency specific Responses are not frequency specific Tone stimulus is used Click stimulus is used Recording is made from cortical potentials Recording is made from brain stem potentials CERA BERA

78. Electrocochleography

79. Electrocochleography setup The recording electrode is a thin needle passed through the tympanic membrane onto the promontory under L/A or G/A Non invasive Electrode placed on TM Invasive

81. Final Thought Tests are not infallible, they are only as good as those taking, administering and interpreting them…