Audiology Exam 1

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Audiology Exam 1
2011-02-19 19:09:22

Audiology Notes
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  1. Roles of Audiologists:
    "Audiologists serve in a number of roles including clinician, Therapist, teacher, consultant, researcher, and administrator. The supervising audiologist maintains legal and ethical responsibility for all assigned audiology activities provided by audiology assistants and audiology students."
  2. Specific Roles of Audiologists:
    • Evaluate and diagnose hearing loss and vestibular (balance) disorders.
    • Prescribe, fit, and dispense hearing aids and other amplification and hearing assistance technologies
    • are members of cochlear implant teams
    • perform ear-or hearing-related surgical monitoring
    • design and implement hearing conservation programs.
    • design and implement newborn hearing screening programs
    • provide hearing rehabilitation training such as auditory training and listening skills improvement
    • assess and treat individuals, especially children, with central auditory processing disorders
    • assess and treat individuals with tinnitus (noise in the ear, such as ringing)
  3. Word War II
    • Physicians and hearing aid dealers provided hearing care prior to war
    • The war caused a shift of practice to "audiology,"a term made famous by Raymond Carhart around 1945.
    • The hearing care industry jump started audiology into a profession due to the presence of military based aural rehab centers.
    • Soldiers returning from war needed treatment for hearing loss due to excessive high noise levels
    • Increased success in the military provided the transition to the civilian sector.
  4. Academic Preparation
    • The profession of audiology continues to expand its scope of practice due to the increasing rate of technology advances in the hearing health care industry.
    • Degrees Include: B.S, M.S., Au.D.,Sc.D.,PhD.
  5. Since _MM/DD/YYYY__, it is required for audiologists to receive a doctorate in audiology to practice in the field and to become certified by national organizations.
    January 1st, 2007
  6. Licensing and Certification
    • Regulated by a licensing body or registration in the US for every state
    • Licensure is a legal requirement to practice in the field of audiology
    • An audiology license requires completion of required course work, 2,000 hours of clinical practicum and obtaining a passing score on a national examination
    • Certification is not a legal requirement, although is necessary to obtain when dealing with an ASHA accredited university.
  7. State Licensing
  8. ASHA
    CCC- Certificate of Clinical Competence
  9. AAA
    FAAA- Fellow of the American Academy of Audiology
  10. ABA
    Board Certified Audiologist
  11. Prevalence and Impact of Hearing Loss
    • Prevalence of hearing loss increases with age
    • Causes of hearing loss may include excessive noise exposure, middle ear pathologies, anatomical anomalies,trauma, genetics, medications and unknown etiologies
    • Hearing impairment causes mild to sever communication difficulties for people of all ages.
    • It is most detrimental to children who are developing speech and language.
  12. Table 1.1 Prevalence
    • 50 million have tinnitus
    • 30 million exposed to hazardous noise levels
    • 26 million are hard of hearing
    • 10 million have some degree of permanent noise-induced hearing loss
    • 2 million are classified as deaf
    • Approx. 6 out of 1000 may be born with hearing impairment
    • Approx 15% of school age kids may fail a school hearing screening due to an ear infection
    • Before age 6, 90% of children in the US will have had at least one ear infection
  13. Prevalence and Impact
    • People with hearing loss have an increased difficulty understanding speech, especially in the presence of noise
    • Impact is greatest on prelingual children, but also affects postlingual children and adults due to psychosocial aspects
    • Diagnosis of hearing loss is essential to maintain language acquisition, interact with family/peers, decrease negative educational impact and for psychological well-being and self-perception.
  14. Hearing Loss Impact
    • Bess, et al. (1989)- Progressive hearing loss in older adults is associated with progressive physical and psychosocial function.
    • Grundfast and Carney (1987)- annual costs for treatment of childhood ear infections may be as high as $2 billion in the US
    • 1 out of 6 baby boomers ages 41 to 59 have a hearing loss
    • Hearing aid use can reduce loss of income by approximately 50%
    • Approximately 1 out of every 4 with a loss seek treatment
    • Due to psychosocial/psychological impact, audiologists may sometimes take on a counseling role to aid the patient in acceptance
  15. Clinical Commentary
    • SLPs often find they work in close concert with audiologists
    • It is this frequent coexistence of hearing disorder and speech/language problems that has led the American Speech-Language-Hearing Association to include hearing screening procedures, therapeutic aspects of audiologic rehabilitation, and basic checks of hearing aid performance within the SLP's scope of practice.
  16. Job Settings
    • Medical: contains the largest amount of audiologists
    • Work in diagnostic assessment and aid medical doctors in final diagnosis
    • Educational: work in the school system
    • Less than half the amount needed actually work in the school system
    • Identify and refer kids with hearing loss to medical
    • Pediatrics: focus on the diagnosis and aural rehabilitation of children
    • Primary role is to incorporate/facilitate the parents' efforts to meet the rehab challenges the child and family will face.
  17. Job Settings
    • Dispensing/Rehab: primarily fit and dispense hearing aids and provide aural rehab
    • Primarily involved in private practice
    • Industrial Audiology: work to prevent noise-induced occupational hearing loss
    • Set up hearing conservation programs, provide info on hearing protection and monitor hearing sensitivity
    • 82% consider themselves clinical service providers
    • The 2 major areas of employment setting are Medical Setting and Private Practice
  18. Field of Science concerned with how the body works
  19. Field of Science concerned with how the body functions
  20. Outer Ear
    • Pinna
    • Helix
    • Concha
    • Lobule
    • Tragus
    • Anti-tragus
    • External Auditory Canal/Meatus (EAC)
  21. Middle Ear
    • Tympanic Membrane (TM) aka eardrum
    • Ossicular chain
    • Malleus-connects to TM (hammer)
    • Incus (Anvil)
    • Stapes (stirrups)
    • Eustachian tube
  22. Inner Ear
    • Oval Window; area where stapes attaches to cochlea
    • Cochlea: Hearing Mechanism
    • Round Window
    • Semi-circular canals: Balance
    • VIII Nerve
    • Facial Nerve: 12th nerve
  23. Outer Ear
    • The aurical or pinna is the largest portion
    • It's shape allows sound to funnel into the EAC
    • It gathers environmental sounds
    • Aids in localization
  24. Outer Ear
    • External Auditory canal (EAC)
    • The opening begins at the concha
    • Extends toward the midline at an upward angle in adults and is approximately 1 inch
    • Outer portion passes through cartilage: contains hair follicles
    • Inner portion runs to the TM: no glands or hair follicles for this portion
    • Provides protection for the TM
    • Acts as a filter for sounds
  25. Tympanic Membrane
    • Beginning of the middle ear
    • Provides a barrier between the outer elements
    • Protects the middle ear from external pathogens
    • Extremely thin and subject to trauma
  26. Smallest bone in the human body
  27. Eustachian Tube
    • Connects the middle ear to the back of the throat(nasopharynx)
    • Provides aeration to the middle ear to keep it bathed in air
  28. Inner Ear
    • Cochlea
    • Connected to the middle ear by the stapes fitting into the oval window
    • Fluid filled spaces aid in the transmission of sounds to the auditory nerve (8th nerve)
  29. Inner Ear
    • Semi-Circular Canals
    • 3 canals that lie at 90 degree angles of each other
    • They are membranous and are contained in a larger bony cavern
    • Primarily responsible for balance
  30. Pathways of Sound
    • Air Conduction: depends on the functioning of the outer, middle and inner ear and also the neural pathways beyond
    • Bone Conduction: bypasses the outer and middle ear and relies on the inner ear and beyond
  31. Types of Hearing Loss
    • Conductive Hearing Loss
    • Attenuation: decrease in the strength of sound
    • Blockage of the outer and/or middle ear will result in a conductive loss and an attenuation of sound
    • Impaired air conduction (AC) with normal bone conduction
  32. Sensorineural Hearing Loss (SNHL)
    • The hearing loss by bone conduction (BC) will be as great as the loss by air conduction (AC)
    • When the same amount of attenuation is present for BC and AC, the conductive mechanism can be ruled out
    • Intact outer/middle ear, but problems with cochlea or pathways beyond
  33. Mixed Hearing Loss
    • Problems occur in both the conductive and sensorineural components
    • Loss is present due to sensorineural abnormality, but conductive loss is greater
    • Conductive loss is greater due to attenuation by the outer and/or middle ear plus inner ear problems
  34. Nonorganic Hearing Loss
    • Either have normal hearing or insufficient auditory pathology to explain the extent of the loss
    • Consciously faking for financial gain (malingering) or a psychological disorder manifested a symptom of hearing loss (psychogenic hearing loss)
  35. Hearing Tests
    • Early hearing testing consisted of the use of noisemakers, hand claps, pocket watches, tuning forks, etc.
    • Today’s technology allows for frequency specific testing to locate the area of dysfunction along the auditory pathway
  36. Tuning Fork Testing
    • Emits a tone at a particular pitch and has a clear musical quality
    • The air conduction tone that is emitted is a relatively pure tone that is free of overtones
    • Set into vibration by holding the stem and striking the tines against a firm surface
    • Any diagnostic value is limited to the specific pitch of the fork
  37. Tuning Fork: Schwabach Test
    • A bone conduction test.
    • Compares the patient’s hearing to the examiner
    • Stem is placed on the mastoid process
    • Normal = stop hearing at the same time
    • Diminished = patient stops hearing before examiner (SNHL)
    • Poorly diagnoses CHL and MHL
  38. Tuning Fork: Rinne Test
    • Compares BC to AC
    • Stem is placed on mastoid and tines are placed near the pinna
    • Positive: normal or SNHL – louder next to ear than behind the ear
    • Negative: CHL – louder behind the ear
    • False Negative: opposite cochlea responds (crossover)
  39. Tuning Fork: Bing Test
    • occlusion effect – close off ear canal and the BC loudness increases
    • Primarily low pitched sounds
    • Present for SNHL, but absent with CHL
    • Positive: normal/SNHL – change in loudness during open and close of ear canal
    • Negative: CHL – no change in loudness as canal is opened and closed
  40. Tuning Fork: Weber Test
    • Tests lateralization (left, right, both or midline)
    • Stem is placed on forehead (midline)
    • Normal/same amount of loss: midline
    • SNHL: hear tone in better ear
    • CHL: hear tone in poorer ear
  41. 2 equal tones presented with different loudness levels, the louder will be perceived
    Stenger Principle
  42. Tuning Fork Info
    • Tuning fork tests are not used regularly by audiologists due to technology advancements
    • Otologists still use forks for quick, in office testing
  43. What is Sound?
    Defined in terms of psychological or physical phenomena
  44. Sound is an auditory experience – the act of "hearing" something, means it is _____.
  45. A series of disturbances of molecules in an elastic medium such as air.
    • Physical
    • It is essentially a form of energy.
  46. Elasticity
    • Essentially the springiness of a medium.
    • Increases as the distance between molecules is decreased
    • If you squeeze a rubber ball, it temporarily changes shape, but eventually restores its original shape
    • The rate at which this occurs is the elasticity
    • Solids are more closely “packed” together, so a solid is more elastic than a liquid
  47. Vibration
    • Vibration is the source of the creation of sound
    • Refers to the back and forth motion of a mass
    • The energy created by vibrations create a point of disturbance in a medium, striking and bouncing off adjacent molecules
  48. Waves
    • Definition: succession of molecules being shoved together and pulled apart
    • Made up of successive compressions and rarefactions
  49. When molecules are forced closely together and thus create increased or higher pressure it is called _____.
  50. When molecules move further apart and create decreased or lower pressure (less condensed)it is called _____.
  51. A type of wave in which, the motion of the molecules is perpendicular to the direction of the wave medium. Example: dropping a pebble in water.
  52. A type of wave in which, molecules vibrate parallel to the direction of the wave medium. Example: wheat in the wind. Do not have crests or troughs b/c they do not move up an down.
  53. Moving energy equals
    Kinetic Energy
  54. Essentially stored up energy
    Potential energy
  55. As objects are in movement, they encounter resistance by molecules in the air.
    • This friction converts some of the energy in the initial movement of the object into heat
    • Friction causes the object to slow down its movement
  56. One compression and one rarefaction of a sound wave is called a ________.
  57. The number of cycles of vibration completed during a time period is called _________.
  58. In acoustics, the reference unit of time is usually
  59. Cycles per second:
    if the time required to complete a cycle is one second, the frequency would be noted as 1 cycle per second (cps)
  60. More commonly used instead of cps when describing the unit of frequency of sound...
  61. As ________ decreases, frequency increases. ex: strings on an instrument (shorter string = higher frequency)
  62. As ________ increases, the frequency decreases. Ex: increased thickness of musical strings = lower tones
  63. As ________ increases, the frequency at which the body is most easily made to vibrate decreases.
  64. The natural rate of vibration of a mass is called its ____________.
    Resonant Frequency
  65. Resonant Frequency
    • When an object is oscillating at an optimum rate and amplitude
    • This is the optimum frequency of a vibrating object due to its characteristics
    • Resonant frequency is why a glass may shatter when a perfect note is played in its presence
  66. Defined as the distance from the baseline to the point of maximum displacement of a wave...The distance the mass moves from the point of rest. Determines the intensity of sound and is related to the force with which the original particle disturbance was created. Increased intensity = increased ______
  67. An objective (able to be seen; measureable; physical) term and is the amount of sound energy per unit of area is called __________.
  68. A subjective (not tangible; psychological) impression of the power of a sound is called _________.
  69. The speed with which a sound wave travels from the source to another point is called_________.
  70. Velocity
    • Elasticity, density and temperature all influence velocity
    • Sounds travel faster through solids than through liquid and faster through liquid faster than gas due to density of the object.
    • When velocity is increased, acceleration takes place
  71. Wavelength
    • The length of a wave is measured from any point on a sinusoid (0-360 degrees) to the same point on the next cycle of the wave
    • Wavelength = velocity of sound/frequency
    • W=v/f
  72. Difficulty hearing someone who is speaking in another room occurs due to...
    The longer wavelengths of the lower frequency sounds of vowels more easily move around corners and obstructions than do the shorter wavelengths of the higher frequencies contained in many of the consonants of speech.
  73. The relationship in time between two or more waves is called ______.
    • Phase
    • Different points in the wave can be compared to a standard to determine if they are in phase.
  74. A sound that has all its energy at 1 frequency, creating a pure tone is called a _______.
    • Simple Sound
    • Does not occur naturally
    • Created by tuning forks and pure-tone audiometers
  75. A sound that has energy at more than 1 frequency is called a _______.
    • Complex Sound
    • Ex: Sound created with the human voice, musical instruments and other environmental sounds
  76. The lowest rate of a sound’s vibration. Determined by physical properties of the vibrating body.Essentially the lowest resonant frequency.
    Fundamental Frequency: AKA 1st harmonic
  77. Harmonics AKA Overtones
    • all frequency whole-number multiples of the fundamental
    • The 1st harmonic is the fundamental and the 2nd harmonic is twice the fundamental.
    • Ex: fundamental = 100, so then 200, 300, 400
  78. Complex Sounds
    • Although the fundamental frequency determines all the harmonic frequencies, the harmonics do not have equal amplitude
    • The fundamental frequency in the human voice is controlled by the vocal folds in the larynx
    • By raising or lowering the tongue and moving it forward or back, it changes the frequency and intensity that emphasize some harmonics more than other, changing the amplitudes.
    • The resulting waveform has peaks and valleys
  79. Each of the energy peaks are called _______.
  80. Manipulation of formant frequencies aid in recognition of different vowel sounds.
    • The peaks are numbered consecutively.
    • Expressed as lowest/first (F1), second (F2) and so on.
    • Once the fundamental has been determined, the fundamental is no longer essential for the perception of sound for people with normal hearing.
  81. Average Male fundamental voice frequency
    85-150 Hz
  82. Average Female fundamental voice frequency
    175-250 Hz
  83. __________ is Generated whenever force is distributed over a surface area.
  84. Pressure
    • If an area remains constant, the pressure increases as the force is increased
    • Due to human hearing sensitivity, micropascals (µ Pa) are used to express sound pressure
    • The smallest pressure variation required to produce a just-audible sound to a healthy young ear is approximately 20 µ Pa
  85. The unit of measurement used in audiology for intensity
  86. Decibel
    • Named after the inventor of the telephone, Alexander Graham Bell
    • A decibel (dB) is 1/10 of a Bel
  87. 5 Important Aspects of the Decibel
    • It involves a ratio
    • It utilizes a logarithm
    • It is therefore non-linear
    • It may be expressed in terms of various reference levels
    • It is a relative unit of measure
  88. The decibel scale has 2 main implications
    • Rather than all units of measurement being the same size, each unit is larger than the preceding unit
    • We can compress a wide range of sound pressure between the highest tolerable sound pressure and the sound pressure that can just be heard into a manageable scale ranging from 140 to 0 dB
    • The decibel has no absolute zero
    • This means 0 dB is an intensity value and is not the absence of sound (audiogram)
  89. Intensity Level:Audiologist do not use this level clinically.Primarily used for electrical systems or equipment. The reference for IL is _________.
    Watts (W)
  90. Sound Pressure Level (SPL)
    • Audiologist and acousticians are more accustomed to making measurements of sound in pressure than in intensity terms
    • Used to describe pressure ratios
    • For audiology terms, the reference for sound pressure is
    • .0002 dyne/cm2 or O dB SPL
    • O dB SPL is the smallest amount of sound pressure that will set a human eardrum into motion
  91. Sound Pressure Level (SPL)
    • O dB SPL does not mean silence, only that the output pressure is O dB above the reference pressure.
    • Therefore, 20 µPa is O dB SPL
  92. The ear threshold of pain is ______.
    140 dB SPL
  93. When sound pressure levels are doubled, the # of decibels are increased by __ because they are ratios.
    6. ex: 60 dB + 60 dB = 66 dB
  94. The lowest sound intensity that stimulates normal hearing is called _______.
    zero hearing level (HL)
  95. Hearing Level
    • Used because the ear shows different amounts of sensitivity to different frequencies, so different amounts of pressure are required to stimulate hearing sensitivity
    • Most sensitive from 1000-4000Hz range
    • Written by audiologists as dB HL when dealing with audiograms
  96. The number of decibels of a sound above the threshold of a given individual is the sound’s _______.
    sensation level (SL)
  97. Sound Sensation Level is used in reference to the auditory _______ of a given individual.
  98. A ____ ____ threshold is defined as the level at which the tone is so soft that it can be perceived only 50% of the time it is presented.
    pure tone
  99. If a person can barely hear a tone or speech sound at 5 dB HL, this same sound presented at 50 dB HL will be 45 dB above their threshold (45 dB SL). The same 50 dB HL tone presented to a person with a 20 dB threshold will have a sensation level of ____.
    • 30 dB SL
    • In order to state the person's dB SL, the threshold of the individual (the reference) must be known.
  100. Factors of Sound that remain the same with or without human perception is ___________.
    Physical Acoustics
  101. The study of the relationship between physical stimuli and the psychological responses to which they give rise is called ______________.
  102. The subjective impressions of the "highness" or "lowness" of a sound is called ________.
  103. Pitch relates to _______.
  104. Pitch rises as the frequency of vibration ________.
  105. Range of human hearing is approximately ______________.
    20 to 20,000 Hz (frequencies)
  106. A subjective experience (perception), as contrasted with the purely physical force of intensity is called _____.
  107. Duration and frequency of sounds contribute to the sensation of _____________.
  108. dB is not a unit of _________.
  109. ____________ grows faster for low frequency tones and especially for high frequency tones than for mid-frequencies.
  110. The ability to tell which direction the sound is coming from refers to __________.
  111. Localization
    Results from complex interactions between both ears. Thought to be an early survival skill in the human species. Possible due to relative intensities of sounds and their arrival to two ears (phase). Highly dependent on phase differences in the lows (below 1500Hz) and intensity differences in the highs.
  112. When two sounds are heard at the same time, the intensity of one sound may be sufficient enough to cause the other to be inaudible, which is called _______.
  113. The change in the threshold of a sound caused by a sound with which it coexists is called _________.
  114. Being in a crowded room and not being able to understand a speaker due to the crowd noise (speech interference) is an example of what?
  115. The opposition that a medium offers to the transmission of acoustic energy is the definition of _______.
  116. Impedance
    • The more dense an object, the reater the impedance to the sound wave
    • Greater impedance = smaler amplitude
    • Greater mass attenuates higher-frequency sounds more that lower-frequency sounds
  117. What frequencies carry the majority of speech sounds?
    mid and highs
  118. Impedance is determined by what two factors
    Simple resistance and Complex resistance
  119. Resistance that is not influences by frequency of vibration is __________.
    Simple resistance
  120. Resistance that is influenced by frequency; opposition to energy varies with frequency is __________.
    Complex resistance (reactance)
  121. _______ reactance is determined by mass and stiffness reactance.
  122. As physical stiffness of an object increases, so does _________.
    Stiffness reactance; as frequency increases, stiffness reactance decreases (inverse relationship)
  123. As physical mass of an object or the frequency at which the object vibrates is increased, so does the _____.
    mass reactance; directly related to both mass and frequency
  124. Audiologist are interested in making what 2 kinds of measurements?
    • Hearing ability of patients with possible hearing disorder
    • Sound pressure levels in the environment
  125. The 1st step in quantifying the amount of a patient's hearing loss came with the development of the ______.
    Pure tone audiometer: Allows for a comparison of any person's thresholds to that of an established norm.
  126. The intensity at which a tone is barely audible is one's ____________.
    Hearing threshold
  127. The number of dB above/below the average normal hearing person's thresholds for different pure tones (0 dB HL) is one's _____________.
    Hearing sensitivity
  128. Pure Tone Audiometer
    • Consists of an audio oscillator (generates pure tones of different frequencies)
    • Each tone is amplified to a max of about 110 dB from 500-4000 Hz, with less output above/below these frequencies.
    • Tones are attenuated by using a manual dial or electronic attenuator.
    • As the number is increased, attenuation is decreased.
    • Like a volume dial on a home theater system.
  129. Air Conduction
    Earphones are held in place by a steel headband. Consists of a magnetic device that transduces the electrical translations supplied by the audiometer to a small diaphragm that vibrates according to the acoustic equivalents of frequency and intensity.
  130. Headphones placed on the outside of the ears.
    Supra-Aural Headphones
  131. Bone Conduction
    • The vibrator is placed against the skull on either the forehead or mastoid process.
    • The plastic shell of the vibrator must be set into motion.
    • Vibrating the skull (increased mass)requires greater energy than AC to generate a level high enough to stimulate normal hearing.
    • Frequencies from 250-4000 Hz are used.
  132. Device used for bone conduction.
    Bone conduction Oscillator
  133. Speech Audiometer
    • Part of a clinical audiometer
    • Input signal is provided by a mic or CD player
    • Input level of the signal is monitored by an averaging voltmeter called a VU meter
    • Signal can be presented via AC, BC, or sound field
  134. Sound Field
    • Begins by placing the patient in the sound suite and seating them in a chair.
    • Loudspeakers are placed in the suite and provide the output of a signal
    • Earphones are NOT used in this type of audiological testing.
  135. Sound Level Meters
    • Consist of a mic, amplifier, attenuator and a meter that picks up and transduces pressure waves in the air, measures them electrically and reads out the sound pressure levels in decibels
    • Used to measure background noise levels and are useful in the study of acoustics.
  136. Calibration of audiometers
    • It is a requirement to have annual calibration checks of audiometers.
    • Audiologists perform bologic checks more frequently to monitor their audiometers
    • Assumption of a properly working audiometer without frequent checks can be costly to the audiologist and patient.
  137. Effectiveness of testing relies primarily on what 2 general factors?
    • Reliability: how well a test result is repeatable
    • Validity: whether a test measures what it is supposed to measure
  138. Testing results in 1 of 4 ways
    • True Positive: indicates a disorder correctly
    • True Negative: Eliminates an incorrect diagnosis
    • False Positive: Suggests a diagnosis incorrectly
    • False Negative: Incorrectly eliminates a correct diagnosis
  139. Mathematical model for testing how well it correctly diagnoses a disorder (true positive) is _____.
  140. Mathematical model for testing how well it rejects an incorrect diagnosis ( true negative); opposite of sensitivity is called ____________.
  141. Mathematical model for testing percent of false positive and false negative results is called _______.
  142. Mathematical model for testing percent of true positive and true negative results is called ________.
    Predictive Value
  143. Pure Tone Testing
    • Pure tone tests are essentially electronic extension of the tuning fork tests.
    • Performing these tests is referred to as audiometry.
    • Purpose: interpretation of results to determine type and extent of a patient's hearing loss.
    • Test reliability relies on calibration of equipment, test environment, patient performance, and examiner sophistication.
    • Audiometry measures patient's responses to stimuli that we interpret as representing hearing.
  144. Pure Tone Audiometer
    • Used to determine hearing Thresholds, which are compared to a set of norms across specific frequencies.
    • American National Standards Institute (ANSI) mandates very specific standards for audiometers, so quality or performance should no be an issue.
  145. Pure tone Audiometer
    • Most audiometers test Air conduction (AC) signals from : 125, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, 6000, and 8000 Hz.
    • Extended High Frequency audiometers test frequencies from 8000-20,000 Hz
  146. What is the purpose for testing extended high frequencies from 8000 to 20,000 Hz?
    Usually for medical or industrial reasons: (chemo-therapy)
  147. Pure tone audiometer
    • Intensities for air conduction range from -10 to 110 dB HL from 500-6000Hz
    • Slightly lower intensity for 125, 250, and 8000Hz
  148. Pure Tone Audiometer
    • Bone Conduction (BC) audiometry tests frequencies from: 250-4000 Hz
    • 50 dB fro 250 Hz and 70-80 dB at 500 Hz and above
  149. Intensity levels are substantially lower than for air conduction because:
    • The power required to drive the BC vibrator is much greater than for the AC headphones.
    • The higher intensity causes harmonic distortion, especially in the low frequencies.
    • High intensities may result in the patient feeling rather than hearing the stimulus (Vibro-Tactile)
  150. Test Environment
    • Sound-Isolated Chambers
    • removing all sound from a room is IMPOSSIBLE
    • Audiologic suites/booths are sound treated to attenuate as much noise as possible
    • may be custom built or pre-fabricated.
    • Use of a double or triple pane window allows for sound treatment while preserving the ability to observe the patient's responses
  151. Test Environment
    • Weakness of Sound Suites/Booths
    • Ventilation systems
    • The rooms require a tight enclosure to decrease ambient noise, decreasing air circulation
    • The use of fans and motors to cool the booth can b troublesome for testing
    • Sometimes the air is connected directly to the building ducts, but caution is necessary due to the ventilation noise.
    • Lighting should be INCANDESCENT
    • Fluorescent lights can put off a 60 Hz hum that can cause a distraction to the patient
  152. Test Environment
    • Supra-Aural Earphones
    • Earphone cushions do NOT provide sufficient attenuation of most background noise to get to 0dB HL for normal hearing.
    • Insert Earphones
    • Increases attenuation of background noise
    • The deeper the insertion of the foam plug, the greater the attenuation
    • Also allows for easier masking for AC and BC
    • BC Oscillator
    • Testing does NOT cover the ears, so masking effects of room noise may affect BC, but not AC
  153. Manual Pure-Tone Audiometry
    • The Patient's Role
    • Testing patients varies significantly due to age, intelligence, education, motivation and especially cooperation.
    • Adult vs. pediatric testing techniques vary significantly
    • Patients usually respond best to instruction given orally
    • Patients must accept their role and responsibility in testing to obtain reliable,valid responses
  154. Manual Pure-Tone Audiometry
    • Patient Response
    • The most important step is to make sure the patient understands the instructions
    • Instruct the patient to raise their hand as soon as they hear the tone and lower it when they no longer hear it
    • DO NOT place the earphones on the patient until AFTER the instructions have been fully given.
  155. Manual Pure-Tone Audiometry
    • Patient Instructions
    • Response format can vary from raising hand, saying "yes", clapping hands, putting toys in a bucket, pushing a button etc.
    • Always be aware of false negative and false positive responses
    • When this occurs in excess, stop testing and reinstruct the patient regarding appropriate responses.
  156. Manual Pure-Tone Audiometry
    • Clinician's Role
    • Make patient's aware of their task
    • Provide verbal, face to face instruction
    • Remind them to raise their hand ANY time they believe they hear the signal
    • Tell them you will be testing both ears and what ear you will be starting with
    • Warn them that the tones will vary in pitch
    • Loudness is irrelevant; if they hear anything, they should respond appropriately
  157. Manual Pure-Tone Audiometry
    • Clinician's Role
    • Patient Positioning
    • Never allow them to be in a position to where they can observe your movement
    • Be aware of your small eye, hand, arm, or body movements because they provide cues.
    • Positioning depends on the age of the patient
    • Child: try to stay in their visual field to keep occasional eye contact
    • Adult: Picks up on more visual cues, so you may need to face their back towards you
  158. Air Conduction Audiometry
    • Purpose: Specify the amount of a patient's hearing sensitivity at various frequencies
    • Results can specify the degree of loss
    • Cannot specify whether the abnormality is conductive, sensorineural or both
  159. Air Conduction Audiometry
    • Earphones
    • push back any interfering hair and remove earrings when possible
    • Remove eyeglass when possible
    • Supra-aural earphones should be checked for proper placement over the ear canal and to check for a collapsed canal
    • Can be checked prior to placement of earphones by checking movement of pinna against the head
    • Insert earphones decrease the need for some of the above
  160. Air Conduction Audiometry
    • Procedure
    • Ear selection is only important if patient has a better hearing ear
    • Most audiologists start with the right ear to keep continuity of testing procedures
    • Pediatric testing involves switching back and forth between ears to obtain as much information as possible with limited time
    • Testing begins at 1000Hz and ascends to higher frequencies
    • Thought to have better test reliability
    • Most easily heard by the majority of people
  161. Air Conduction Audiometry
    • Testing usually performed at octave points
    • Mid Octaves: 750, 1500, 3000, and 6000 Hz; tested when a difference of 20 dB is noted between adjacent octaves
    • Pure tones may be pulsed automatically or manually or continuous.
    • Descending and ascending techniques are also employed
  162. Air Conduction Audiometry
    • ASHA Guidelines
    • Present tone at 30 dB HL
    • If no response, raise level to 50 dB HL
    • Continue to raise in 10 dB steps until the tone is heard
    • When a response is obtained, lower the tone by 10 dB steps until no response (below threshold)
    • Raise the tone 5 dB until the response is obtained again.
    • Repeat process until 50% threshold criterion is met (correctly identify at least 3 out of 6 tone presentations)
  163. The process of stepping down 10 dB and up 5 dB, in order to find the patient's threshold is know as ____________.
  164. Air Conduction Audiometry
    • Continuous Vs. Pulsed pure tones
    • Pulsing a tone was tested to have increased awareness by patients
    • Makes the tone stand out in presence of interfering ear/head noise
    • Warbled tones (frequency modulated) can aid in patient response
    • Used when obtaining sound field results to eliminate standing waves
  165. Air Conduction Audiometry
    • Results are plotted on an audiogram
    • Pure Tone Average (PTA): 3 frequency (500,1000, 2000Hz) average to help check reliability of testing
    • Useful for predicting the threshold for speech
    • Establishes the degree of communication impact imposed by hearing loss
  166. Air Conduction Audiometry
    • Hearing loss as a percentage
    • Defining a hearing loss by a percentage negates the concepts of frequency and intensity
    • May be used by physicians to aid in patient comprehension of hearing loss
    • Use of percentages ignores audiometric configuration and only looks at the average hearing loss
  167. Audiogram symbol for left ear on audiogram is _______.
    X: blue
  168. Audiogram symbol for right ear on audiogram is ______.
    O: red
  169. Audiogram symbol for left ear unmasked bone conduction is _____.
  170. Audiogram symbol for right ear unmasked bone conduction is ______.
  171. Audiogram symbol NR means ________.
    No response (to audometer limits)
  172. Audiogram symbol S means _________.
    Sound field testing
  173. Audiogram symbol A means __________.
    Aided Sound field testing: Hearing aids are in
  174. On an audiogram __________ is shown on the horizontal line and goes from low to high, left to right.
  175. On an audiogram __________ is shown on the vertical line and increases from top to bottom.
  176. Symbols on the audiogram are plotted after a threshold is obtained under the test frequency and corresponding number (dB HL)
  177. Normal threshold for adults is _____ dB and for kids _____ dB.
    25 for adults and 20 for kids
  178. Bone Conduction Audiometry
    Purpose: determine the patient’s sensorineural sensitivity
  179. Hearing by BC arises from what 3 phenomenon?
    • Distortional BC
    • Inertial BC
    • Osseotympanic BC
  180. Distortional BC
    • When the skull is set into vibration, the bones of the skull become distorted, resulting in the distortion of the structures of hearing within the cochlea
    • This distortion activates certain cells and gives rise to electrochemical activity that is identical to the activity created by an AC signal
  181. Inertial BC
    While the skull is moving, the ossicular chain, owning to its inertia, lags behind so that the stapes moves in and out of the oval window
  182. Osseotympanic BC
    • Oscillation of the skull causes vibrations of the column of air in the outer ear canal
    • Some of these sound waves escape the ear and some travel the same pathway as would by air conduction
  183. Bone Conduction Audiometry: Placement is usually on the ___________, but can be on the forehead
    mastoid process
  184. The mastoid was chosen due to:
    • BC tones are loudest from the mastoid in normal hearing persons
    • Due to the mastoid process’s proximity to the ear being tested
    • Testing procedure is similar to air conduction
  185. Bone Conduction Audiometry
    • Procedure
    • Both ears must be uncovered due to an increase in sound intensity when the ear is occluded
    • This is referred to as the Occlusion Effect (OE) and effects frequencies from 1000 Hz and below
    • Does not effect conductive hearing losses as much due to the attenuation of sound caused by the hearing loss
  186. Bone Conduction Audiometry
    • Procedure:
    • Deciding which ear to test first is unimportant due to cochlea locations
    • Symbols are plotted on the audiogram in the same fashion as air conduction
  187. Audiogram Interpretation
    • Results must be looked at for each frequency in terms of:
    • Amount of hearing loss by AC
    • Amount of hearing loss by BC
    • Relationship between AC and BC
  188. Audiogram Interpretation
    • Conductive Hearing Loss (CHL)
    • Bone conductive component is within normal limits across all frequencies
    • Air conduction results show the loss of sensitivity
  189. The difference between the air and bone conduction thresholds is known as the _______.
    Air Bone Gap (ABG)
  190. Conductive Hearing Loss Audiogram
    These symbols >>>>> appear within normal limits/above these symbols XXXXX, which can be in a downward/upward slope.
  191. Audiogram Interpretation
    • Sensorineural Hearing Loss
    • AC results show the total amount of loss
    • BC results show the amount of SNHL
  192. For a Sensorineural Hearing Loss the Air Bone Gap (ABG) is ___ dB, showing NO conductive involvement.
  193. Sensorineural Hearing Loss Audiogram
    These symbols >>>> appear 0-10 dB above these symbols XXXX anywhere on the audiogram.
  194. Audiogram Interpretation
    • Mixed Hearing Loss
    • Air conduction thresholds show a conductive hearing loss
    • Bone conduction thresholds show a sensorineural hearing loss
  195. For a Mixed Hearing Loss the air bone gap (ABG) shows a conductive component and a gap greater than ___ dB.
  196. True or False: Bone Conduction CAN be worse than Air Conduction?
    FALSE: Bone Conduction will NEVER be worse than Air Conduction.
  197. Air-Bone Relationships
    • Hearing by BC is the same by AC in individuals with normal hearing or SNHL
    • Hearing by AC is poorer than by BC in patients with conductive or mixed hearing losses (some air bone gap)
    • Hearing by BC poorer than by AC should not occur because both routes ultimately measure the integrity of the sensorineural structures
  198. Tactile Responses
    • In the presence of severe losses, it is NOT possible to tell whether responses obtained at the highest limits of the audiometer are auditory or tactile
    • Some patients may feel the vibrations of the BC vibrator due to the intensity of the output signal
  199. Cross Hearing in AC and BC
    • When hearing sensitivity is significantly better in one ear, the possibility of crossover exists
    • Sound can escape via AC or BC when the intensity is loud enough to reach the better hearing ear’s threshold
  200. When sounds travel from one side of the heard to the other, a certain amount of energy is lost in transmission, this is known as _______.
    Interaural Attenuation (IA)
  201. Interaural Attenuation (IA)
    • The loss of intensity of a sound introduced to one ear and heard by the other ear
    • The minimum interaural attenuation (IA) for AC supra-aural earphones is 40 dB
    • Insert earphones are around 70 dB
  202. Cross Hearing AC and BC
    • When performing BC testing, it is difficult to know which cochlea is being stimulated, regardless of where the BC oscillator is placed
    • Crossover is always possible for BC due to the anatomical positioning of the cochleas
  203. The minimum Interaural Attenuation for BC is _ dB.
    0: Air-bone gaps over 10 dB are considered significant.
  204. Masking
    • When vision is being tested, the eye NOT being tested is covered (masked)
    • For hearing, this is accomplished by delivering a noise to the NONTEST ear to remove it from the test
  205. Masking
    • When crossover is suspected, the nontest ear must be removed to determine:
    • If the original responses were obtained through the nontest ear
    • If they were the nontest ear responses, what are the true thresholds of the test ear
  206. Masking
    • Masking noise varies depending on the type of testing being performed
    • Masking of a pure tone is most effective by using frequencies immediately surrounding that pure tone
  207. In regards to masking, the minimum amount of noise required to make a given signal inaudible is referred to as _______.
    Effective Masking
  208. In regards to masking, the small shift in threshold of the test ear when masking is introduced into the nontest ear is referred to as __________.
    Central Masking
  209. In regards to masking, when the noise is actually so intense in the masked ear that is crosses the skull and masks the test ear it is called ___________.