Speech Audiometry, OAE, AMR,

  1. Speech Audiometry
    • better estimate of hearing handicap then pure tones because it incorporates sensitivity and acuity
    • -they are not great diagnostic tools
  2. SDT-Speech detection Threshold
    A measure of sensitivity, it is the lowest level in dB that a subject can detect speech. The speech does not need to be understood just need to be able to hear someone talking
  3. SRT- Speech recognition threshold
    • Better than SDT and is also a sensitivity measure.  The difference is the speech must be understood and is often tested with Spondees. (greyhound, sidewalk, mailman)
    • -you test it in the same fashion as pure tones but the client must repeat the word.
    • -this measure should agree with your pure tone average at 500, 1000 and 2000
  4. MCL
    most comfortable listening leve
  5. Acuity measures
    • the % correct supra measures
    • -how well can acoustic cues of speech above threshold be distinguished
  6. word recognition scores (WRS)
    • not a discrimination task and cannon be predicted by the pure tone audiogram
    • -not good reliability or validity
    • -can help with amplification, how much struggle, lesion site
    • -the more words the better or more reliable it is
  7. OAE
    • sounds produced by the cochlea, it is the sound of outer hair cells dancing. rules out middle and outer ear problems (conductive loss)
    • -could still be an inner ear problem
    • -they are used for neonatal screenings, early signs of NIHL, Malingering, ototoxicity monitoring
    • -Spontaneous OAEs happen in the absence of input
    • -evoked OAEs is when there is a response to our manipulation
  8. DPOAE- Distortion product OAE
    • 2(f1)-f2= where to measure the DPOAE
    • -not a test of hearing, only a test of OHC functioning. we use them to infer normal hearing. good for infants and dif populations 
    • -If there is no activity at the area we calculated(in the above equation) then there is an OHC malfunction
    • -we measure the amplitude(dB)
  9. Auditory Evoked Potential
    • sounds can cause certain centres of the auditory system to create a measurable output
    • -ABR is a type of AEO: we measure them based on shape and latency
  10. ABR-Auditory brain stem response
    • not a test of hearing, they test IHC and brainstem function
    • -early latency response and happens automatically after stimulus in a healthy system
    • -we use them for threshold estimates in hard to test populations
    • OAE + ABR = good idea of problem area
  11. ABR waves
    • 1. Cochlea + VIII CN function
    • 2. VIII CN
    • 3. Pons
    • 4. Pons
    • 5. Midbrain
  12. ABR wave outcomes
    • At high intensities (70db) we should have clear responses from 1,3,5
    • -then intensity is lowered until wave 5 (midbrain) is undetectable which is your ABR threshold
  13. info obtained from ABR
    • 1. absolute latencies of all waves
    • 2. interpeak intervals
    • 3.wave amplitudes
    • 4 threshold of wave V (midbrain)=as you near it the latency goes up and amplitude goes down
  14. ABR= Conductive hearing loss
    will elevate thresholds by air and slow all waves down by the same amount
  15. ABR= Sensorineural
    Prolong and elevate wave V threshold
  16. ABR=Retrocochlear lesions (tumours, MS)
    • -prolong interpeak intervals,
    • -wave V latency different between ears
    • -amplitude ratios are abnormal (wave 5 is usually larger than wave 1)
    • -wave V is prolonged or absent at high intensities
  17. VRA visual reinforcement audiometry
    kid turns to sound then is reinforced with a toy of some sort that is lit up in a box. appropriate for kid 7-30 months.  Must condition the response first
  18. Play audiometry
    • 30m-5 years approx
    • start at 50db to teach the game then start the test
Card Set
Speech Audiometry, OAE, AMR,
Speech Audiometry