Contents. Exercises and Questions. Answers

Transcription

1 Contents Preface vii Exercises and Questions 1 Anatomy of the Auditory and Vestibular Systems 1 2 Properties of Sound 11 3 Functions of the Auditory System 27 4 Pure-Tone Audiometry 33 5 Audiogram Interpretation 37 6 Speech Audiometry 71 7 Physiological Measures 85 8 Selected Disorders of the Auditory System 99 9 Hearing Aids Audiology as a Career 117 Answers 1 Anatomy of the Auditory and Vestibular Systems Properties of Sound Functions of the Auditory System Pure-Tone Audiometry Audiogram Interpretation Speech Audiometry Physiological Measures Selected Disorders of the Auditory System Hearing Aids Audiology as a Career 201 v

2 6 AUDILGY WRKBK 1.20 Label the indicated items on the following figure of the auricle. From Mosby s Guide to Physical Examination (p. 315), by H. M. Seidel, J. W. Ball, J. E. Dains, and G. W. Benedict, 2003, Saint Louis, M: Mosby, Inc. Copyright 2003 by Mosby, Inc. Adapted with permission. a. b. c. h. d. g. e. f. a. b. c. d. e. f. g. h.

3 ANATMY F THE AUDITRY AND VESTIBULAR SYSTEMS Label the indicated items on the following figure of the ossicular chain. From The Surgical Anatomy of the Temporal Bone and (p.76), by B. J. Anson and J. A. Donaldson, 1967, Philadelphia, PA : W. B. Saunders. Copyright 1967 by W. B. Saunders. Adapted with permission a. h. b. g. f. c. e. d. a. b. c. d. e. f. g. h.

4 8 AUDILGY WRKBK 1.22 Label the indicated items on the following figure of the inner ear labyrinths. From Clinical Neurophysiology of the Vestibular System (p. 29), by R. W. Baloh and V. H. Honrubia, 2001, New York, NY: xford University Press. Copyright 2001 by xford University Press, Inc.. Adapted with permission. a. l. k. b. j. i. c. h. g. d. e. f. a. b. c. d. e. f. g. h. i. j. k. l.

5 ANATMY F THE AUDITRY AND VESTIBULAR SYSTEMS Label the indicated items on the following figure of the cross section of the cochlea. From Bloom and Fawcett: A Textbook of Histology (p. 929), by D. W. Fawcett, 1994, New York, NY: Chapman and Hall. Copyright 1994 by Chapman and Hall. Adapted with permission. a. i. b. h. c. d. e. g. f. a. b. c. d. e. f. g. h. i.

6 10 AUDILGY WRKBK 1.24 Label the indicated items on the following figure of the organ of Corti. b. a. n. c. m. d. l. e. f. g. h. i. k. j. a. b. c. d. e. f. g. h. i. j. k. l. m. n.

7 2 Properties of Sound 2.1 Vocabulary review. Match the following descriptions with the appropriate term. Not all of the terms will be used. Descriptions: 1. formula to obtain an average amplitude for the waveform 2. way to describe complex vibrations by plotting a graph that shows the amplitudes as a function of frequency and/or the starting phases as a function of frequency 3. the study of how sound is perceived 4. a special type of band-pass filtered noise where there is a relatively restricted range of frequencies 5. the measure of force distributed over an area and has units of dynes/cm 2, Newton/m 2, or micropascals 6. graphic representation of how auditory sensitivity changes with frequency 7. the number of cycles that occur in one second 8. these nonsinusoidal periodic vibrations typically have a tonal or buzzing quality 9. the unit of measure for frequency 10. the decrease in the intensity of a sound with an increase in distance 11. the distance a pure tone travels in one cycle 12. when the vibratory pattern repeats at regular intervals 13. the time that it takes to complete one cycle 14. vibration in which the pattern does not regularly repeat itself over time 11

8 12 AUDILGY WRKBK w/m the study of the physical properties of sounds and how they travel through the air 17. expressed in degrees relative to the angle around the circle 18. the phase of vibration that creates a decrease in the density of air molecules, which corresponds to a decrease in sound pressure 19. determining amplitude by measuring the amplitude change that occurs between the positive peak and the negative peak 20. simple vibrations that are commonly used during audiological testing µpa 22. the phase of vibration that creates an increase in the density of air molecules, which corresponds to an increase in sound pressure ,000 Hz 24. the measure of power distributed over an area; has units of watts/cm 2 or watts/m 2 Terms: a. acoustics b. psychoacoustics c. pure tones d. condensation e. rarefaction f. frequency g. Hertz h. noise i. frequency range of audibility for humans j. period k. starting phase l. root-mean-square (RMS) amplitude m. peak amplitude n. peak-to-peak amplitude o. inverse square law p. sound intensity q. sound pressure r. fundamental frequency s. reference level for intensity t. reference level for pressure u. threshold of audibility curve v. harmonics w. wavelength x. spectrum y. octave z. periodic vibration aa. filtering bb. complex periodic vibration cc. aperiodic vibration dd. narrow-band noise

9 PRPERTIES F SUND What is the speed of sound in air and how does it compare to the speed of light? Is the speed of sound in air faster or slower than the speed of sound in water? 2.3 Given the following frequencies, calculate the period in seconds and in milliseconds Hz Hz Hz Hz Hz Hz 7. 12,500 Hz 8. 20,000 Hz Hz Hz 2.4 Given the following periods, calculate the frequency seconds seconds

10 14 AUDILGY WRKBK seconds seconds seconds seconds seconds seconds seconds seconds 2.5 Given the following periods in milliseconds (ms), convert the period to seconds and calculate the frequency (Hz) ms ms ms ms ms 6. 2 ms ms

11 PRPERTIES F SUND ms ms ms 2.6 Given the following time domain waveforms, calculate the frequency. 2 1 Amplitude (aribtrary) Time (ms) 1. Frequency

12 AUDIGRAM INTERPRETATIN Given the following audiograms, write a description of the hearing loss in the space provided below. Example 1. Frequency (Hz) Hearing Level (db HL) re: ANSI > > > > > Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

13 58 AUDILGY WRKBK Example 2. Frequency (Hz) Hearing Level (db HL) re: ANSI [ [ [ [ [ Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

14 AUDIGRAM INTERPRETATIN 59 Example 3. Frequency (Hz) Hearing Level (db HL) re: ANSI > ] ] ] ] Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

15 60 AUDILGY WRKBK Example 4. Frequency (Hz) Hearing Level (db HL) re: ANSI < < < < < Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

16 AUDIGRAM INTERPRETATIN 61 Example 5. Frequency (Hz) Hearing Level (db HL) re: ANSI ] ] ] ] ] Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

17 62 AUDILGY WRKBK Example 6. Decibels Hearing Level (db HL) re: ANSI Frequency (Hz) < < < < < Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Description:

18 AUDIGRAM INTERPRETATIN 63 Example 7. Frequency (Hz) Hearing Level (db HL) re: ANSI > > > > > > Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Description:

19 90 AUDILGY WRKBK 5. Negative pressure tympanogram Admittance (mmho) Type: Using the following tympanograms and the available data, determine what the possible disorder might be. For the last problem, determine the tympanometric width and if it is within normal limits or not. Refer to Table 7 1 in the workbook for assistance with this exercise. 2.5 Compensated V ec = 0.2 mmho Y tm = no peak 2.0 TPP = no peak (mmho) Admittance Possible disorder? Air Pressure (dapa)

20 PHYSILGICAL MEASURES 91 Admittance (mmho) 2.5 Compensated V ec = 0.9 mmho Y tm = 3.9 mmho 2.0 TPP = 50 dapa Possible disorder? Air Pressure (dapa) Admittance (mmho) 2.5 Compensated V ec = 1.1 mmho Y tm = 0.6 mmho 2.0 TPP = -50 dapa Possible disorder? Air Pressure (dapa)

21 92 AUDILGY WRKBK V ec Y tm TPP Compensated = 1.3 mmho = no peak = no peak Admittance (mmho) Possible disorder? Air Pressure (dapa) V ec Y tm TPP Compensated = 5.2 mmho = no peak = no peak (mmho) Admittance Possible disorder? Air Pressure (dapa)

22 PHYSILGICAL MEASURES V ec Y tm TPP Compensated = 0.6 mmho = 0.5 mmho = -25 dapa (mmho) Admittance Air Pressure (dapa) 6. Tympanometric width? Inside or outside normal limits? 7.6 Describe the recording set up and stimuli used for an ipsilateral acoustic reflex test. 7.7 Describe the recording set up and stimuli used for a contralateral acoustic reflex test. 7.8 What is the definition of an acoustic reflex threshold? What strategies are used to help establish the patient s acoustic reflex threshold? 7.9 What are the three conditions that are necessary in order to elicit an acoustic reflex?

23 94 AUDILGY WRKBK 7.10 Given the following examples, fill in the most expected pattern of acoustic reflex thresholds. Refer to Table 7 2 in the workbook for help with this exercise. 1. RE: normal hearing and function LE: 45 db conductive loss R L Stim R Probe L Stim L Probe R 2. RE: 60 db cochlear loss LE: 40 db cochlear loss R L Stim R Probe L Stim L Probe R 3. RE: impacted cerumen with 15 db ABG LE: 7th nerve palsy distal to stapedial branch R L Stim R Probe L Stim L Probe R 4. RE: 70 db cochlear loss LE: normal hearing and function R L Stim R Probe L Stim L Probe R 5. RE: 8th nerve tumor with severe SN loss LE: 7th nerve tumor proximal to the stapedial R L Stim R Probe L Stim L Probe R 6. RE: 35 db cochlear loss LE: normal hearing with perforation R L Stim R Probe L Stim L Probe R 7. RE: 35 db conductive loss LE: 35 db cochlear loss R L Stim R Probe L Stim L Probe R

24 SELECTED DISRDERS F THE AUDITRY SYSTEM 105 Questions 8.24 through 8.27 are case studies designed to test your understanding of some common disorders of the auditory system through the integration of the audiometric test data. For each case study, fill in the missing test data and provide a possible diagnosis Case Study Susan Stapes is a 7-year-old girl who was seen for audiometric testing due to recent parent and teacher concerns regarding her difficulty hearing from the right ear. Her history is significant for frequent colds, otitis media, and excessive cerumen buildup. Given the following results from tympanometry and speech audiometry, fill in the probable results for pure-tone audiometry and acoustic reflexes. Tympanometry: Admittance (mmho) V ec Y tm TPP Right = 0.1 mmho = no peak = no peak Admittance (mmho) 2.5 Left V ec = 0.6 mmho 2.0 Y tm = 1.1 TPP = -100 dapa Air Pressure (dapa) Air Pressure (dapa) Speech Audiometry: SRT WRS Right % at 70 db Left % at 40 db Acoustic Reflexes: R L Stim R, Probe L Stim L, Probe R

25 106 AUDILGY WRKBK Audiogram: Frequency (Hz) Hearing Level (db HL) re: ANSI Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Decibels Given all of the test results, what is the probable diagnosis? What data is this decision being based on? What are your recommendations for this patient?

26 SELECTED DISRDERS F THE AUDITRY SYSTEM Case Study Len Labyrinth is a 45-year-old male who was seen for audiometric testing due to difficulties understanding speech while in background noise. He also reported a recent onset of tinnitus in the left ear and occasional episodes of dizziness. He denied a family history of hearing loss or any recreational or occupation noise exposure. Given the tympanometric data, draw in the appropriate tympanograms. In addition, calculate the rollover ratio for the speech results. Audiogram: Decibels Hearing Level (db HL) re: ANSI Frequency (Hz) < > < > > < > < < ] Audiogram Key Right Left AC (unmasked) AC (masked) BC (unmasked) < > BC (masked) [ ] No response (on any symbol) Sound-field (non ear specific) S Acoustic Reflexes: R L Stim R, Probe L Stim L, Probe R 95 Absent 95 Absent Speech Audiometry: SRT WRS Positive PI/PB Rollover? Right 10 96% at 50 db; 88% at 90 db Left % at 50 db; 60% at 90 db

27 108 AUDILGY WRKBK Tympanometry: 2.5 Right V ec = 1.3 mmho Y tm = 1.2 TPP = -100 dapa 2.5 Left V ec = 1.0 mmho Y tm = 1.4 TPP = 5 dapa Admittance (mmho) Admittance (mmho) Air Pressure (dapa) Air Pressure (dapa) Given all of the test results, what is the probable diagnosis? What data is this decision being based on? What are your recommendations for this patient?