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Ssidxiii

  1. 1. Synthetic Sentence Identification <ul><li>Developed by Speaks and Jerger (1965) </li></ul><ul><li>Provide sentence material for auditory research and evaluation </li></ul>
  2. 2. <ul><li>Synthetic Sentences developed to control for semantic and syntactic effects </li></ul><ul><li>Closed set identification </li></ul><ul><li>Ten third order approximations. Seven words in length </li></ul><ul><li>Message set consists of ten sentences </li></ul><ul><li>Found to be too easy in quiet </li></ul>
  3. 3. <ul><li>Competition was added </li></ul><ul><li>Can be presented with ipsilateral or contralateral competition </li></ul><ul><li>Trial consists of a random ordering or ten sentences in competition </li></ul><ul><li>Subject responds by identifying the sentence presented from the printed list </li></ul>
  4. 4. <ul><li>One list for one listening condition or intensity level </li></ul>
  5. 5. SSI Sentences <ul><li>Small boat with a picture has become </li></ul><ul><li>Built the government with the force almost </li></ul><ul><li>Go change your car color is red </li></ul><ul><li>Forward march said the boy had a </li></ul><ul><li>March around without a care in your </li></ul><ul><li>That neighbor who said business is better </li></ul><ul><li>Battle cry and be better than ever </li></ul><ul><li>Down by the time is real enough </li></ul><ul><li>Agree with him only to find out </li></ul><ul><li>Women view men with green paper should </li></ul>
  6. 6. PI-PB-PI-SSI Functions <ul><li>Compares PI functions for monosyllabic words and synthetic sentences </li></ul><ul><li>Used to aid the differentiating site of dysfunction </li></ul><ul><li>Procedure: define function for PB words and measure a PI-SSI function in ipsilateral noise at the same presentation levels (at 0dB S/N) </li></ul>
  7. 7. <ul><li>Comparison of function yields diagnostic patterns helpful for both site of lesion and processing paradigms </li></ul>
  8. 8. Cochlear Pattern <ul><li>Dependent on audiometric configuration </li></ul><ul><li>Flat loss-PI-PB-PI-SSI shows similar result </li></ul><ul><li>Sloping audiometric configuration shows SSI recognition better than PBs—likely due to the dependence of PB words on consonant perception (HF more important for PBs) </li></ul><ul><li>Rising configuration. PB recognition better than SSI—the SSI is more dependent on the low frequency information </li></ul>
  9. 9. <ul><li>Frequency relationship is generally predictable. If patterns do not occur, retrocochlear or central involvement should be suspected </li></ul>
  10. 10. NVIII Patterns <ul><li>Normal hearing sensitivity relationships are often exaggerated </li></ul><ul><li>If cochlear, the PBmax and SSImax should not be greater than about 30%; and rollover would not be marked </li></ul>
  11. 11. More Central Patterns <ul><li>SSI usually falls below PB, regardless of audiometric configuration (unlike other sites) </li></ul><ul><li>Large differences in maximum score even with normal hearing sensitivity </li></ul><ul><li>Discrepency contralateral to site of dysfunction </li></ul><ul><li>PB-SSI difference increases with central presbycusis (decreased word rec-peripheral; PB-SSI discrepency-central) </li></ul>
  12. 12. ICM / CCM <ul><li>Differentiate intra-axial brainstem and temporal lobe sites </li></ul><ul><li>Most effective when average thresholds do not exceed 25dB and hearing is symmetrical </li></ul><ul><li>Measured at several message to competition ratios </li></ul><ul><li>ICM-ipsilateral competing message </li></ul><ul><li>CCM-contralateral competing message </li></ul>
  13. 13. CCM <ul><li>For CCM, the Message to Competition ratios are 0, -20, and -40 </li></ul><ul><ul><li>*If the patient can score 100% at -40, other MCRs may be eliminated </li></ul></ul><ul><ul><li>*normal hearing individuals score between 90% and 100% at all MCRs </li></ul></ul>
  14. 14. ICM <ul><li>SSI-ICM is administered at MCRs of +10, 0, </li></ul><ul><li>-10, and -20dB. </li></ul><ul><li>Jerger (1970) mean scores: </li></ul><ul><li>+10: mean 100% 1SD 100% </li></ul><ul><li> 0: mean 94% 1SD 85%-100% </li></ul><ul><li> -10: mean 80% 1SD 70%-92% </li></ul><ul><li> -20: mean 55% 1SD 45%-65% </li></ul>
  15. 15. Brainstem Patterns <ul><li>Poor ICM performance </li></ul><ul><li>Deficit ipsilateral if low-stem, contralateral if hi-stem, if crosses midline—bilateral </li></ul>
  16. 16. Temporal Lobe Pattern <ul><li>Poor CCM performance; can have reduced ICM </li></ul><ul><li>CCM performance is reduced contralateral to affected hemisphere </li></ul>
  17. 17. Summary Comments <ul><li>With cochlear losses the audiometric configuration affects the PI SSI relationship in a predictable manner </li></ul><ul><li>For retrocochlear site, the differences are out of proportion with the audiometric configuration (with rollover) </li></ul><ul><li>For cochlear and NVIII site, the affected ear is ipsilateral to site of dysfunction </li></ul>
  18. 18. Summary Comments (cont.) <ul><li>When the SSI function falls below the PB function (cannot be explained by audiometric configuration), a central disorder should be suspected </li></ul><ul><li>ICM deficits are greater for brainstem dysfunction </li></ul><ul><li>CCM deficits are greater for temporal dysfunction </li></ul>
  19. 19. Case Studies
  20. 20. Case 1 <ul><li>25 year history of noise exposure </li></ul><ul><li>Hearing difficulty, right ear </li></ul><ul><li>Normal pressure compliance </li></ul>
  21. 21. Case 1 <ul><li>PBmax is 100%, left; SSImax is 95% </li></ul><ul><li>PBmax is 30%, SSImax is 80% </li></ul><ul><li>No rollover left, slight on the right </li></ul><ul><li>Right ear shows PB function below SSI consistent with the cochlear configuration </li></ul><ul><li>(also in right Type II Bekesy, Positive SISI, complete recruitment on ABLB; AR thresholds average 65dB HL to 90dB HL) </li></ul>
  22. 22. Case 2 <ul><li>Pt complains of vertigo, tinnitus, and hearing loss, left ear (Diagnosed as Meniere’s) </li></ul><ul><li>Has stable hearing loss on right since childhood (congenital) </li></ul>
  23. 23. Case 2 <ul><li>PBmax is 90%, SSImax is 60% on left </li></ul><ul><li>PBmax is 75%, SSImax is 80% on right </li></ul><ul><li>On the left, the SSImax is 30% below the PBmax-but is consistent with the rising configuration of the audiogram; no rollover </li></ul><ul><li>Inteweaving functions on the right are consistent with the flat audio. Lower AR thresholds suggest recruitment </li></ul><ul><ul><li>(Both ears-Bekesy Type II, positive SISI) </li></ul></ul>
  24. 24. Case 3 <ul><li>Pt complains of distorted speech, right ear </li></ul><ul><li>No other medical ear history </li></ul>
  25. 25. Case 3 <ul><li>No abnormalities, left ear </li></ul><ul><li>For right ear, PI-PB functions fall below the PI-SSI –35%; some of this difference is consistent with the falling audio, but the magnitude is too great!; also 25% rollover for PBs and 40% for SSI. Acoustic reflexes absent or elevated. Pt. had abnormal STAT and Type IV Bekesy </li></ul><ul><li>Ipsilateral results suggests NVIII or low stem </li></ul>
  26. 26. Case 4 <ul><li>Pt complains of decreasing hearing on the right. </li></ul>
  27. 27. Case 4 <ul><li>Sloping hearing loss, right. But, abnormal PI function/lower SSI cannot be explained by audio. </li></ul><ul><li>Note 30% difference between PB and SSI maxima and some rollover, absent/elevated acoustic reflexes ?central </li></ul>
  28. 28. Case 5 <ul><li>Headaches and; balance difficulty; ipsilateral reflexes were present, contralateral elevated or absent </li></ul>
  29. 29. Case 5 <ul><li>SSI-CCM normal; SSI-ICM abnormal on the right. </li></ul><ul><li>ICM depressed contralateral to damaged side? Note absent contra reflexes and present ipsi reflexes (B’stem site?) </li></ul>
  30. 30. Case 6 <ul><li>Blurry vision, dizziness, some slurred speech. No retrocochlear signs on Bekesy, SISI, or tone decay. Acoustic reflexes were present ipsilaterally </li></ul>
  31. 31. Case 6 <ul><li>Both ICM functions are impaired as is a slightly depressed CCM on the left (Hmmm both ICM and CCM; likely suggest midline b’stem dysfunction.lateral lemniscus </li></ul><ul><li>Radiology showed astrocytoma crossing midline at the level of the </li></ul>
  32. 32. Case 7 <ul><li>Head injury to the left; now has headaches and memory difficulties </li></ul>
  33. 33. Case 7 <ul><li>ICM and CCM are depressed on the right. CCM is poorer. </li></ul><ul><li>The poorer CCM is indicative of temporal lobe involvement on the contralateral side </li></ul>

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