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Clinical Studies of Medial Olivocochlear Function

Clinical Studies of Medial Olivocochlear Function . Charles I. Berlin, PhD Linda Hood PhD Thierry Morlet, PhD Shanda Brashears, MCD LSUHSC’s Kresge Hearing Research Laboratory of the South, Dept ORL and Head and Neck Surgery 533 Bolivar Street NO LA 70112 www.kresgelab.org

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Clinical Studies of Medial Olivocochlear Function

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  1. Clinical Studies of Medial Olivocochlear Function Charles I. Berlin, PhD Linda Hood PhD Thierry Morlet, PhD Shanda Brashears, MCD LSUHSC’s Kresge Hearing Research Laboratory of the South, Dept ORL and Head and Neck Surgery 533 Bolivar Street NO LA 70112 www.kresgelab.org Phone: 504-568-4785 Fax: 504-568-4460 Support is acknowledged from NIH, and the Oberkotter, Marriott, HFSP, Kam’s Fund and LSU Foundations.

  2. Clinical Studies of the MOCS using TEOAEs • …quantification of TEOAE suppression in intensity, frequency and phase using ECHOMASTER (see www. Kresgelab.org) • …results with continuous contralateral noise vs. forward masking paradigms. • …Binaural vs. ipsi vs. contra suppression in forward masking paradigms by intensity, spectral level, correlation and time. • …four click train vs. single click data addressing ipsilateral suppression effects.

  3. More results in MOCS Studies • …Development and Aging • ….Gender and laterality effects…changes in laterality after Fast ForWord™ • … absence of suppression in patients with Auditory Neuropathy. • …patients who are obligate carriers of genes for deafness (See Hood et al Poster later today) Differences in Suppression as well as DPOAE characteristics. • …“tough ears” of musicians. • …medicolegal applications in patients with Hyperacusis • …autistic patients who complain of extreme hearing sensitivity (Berard/Tomatis targets).

  4. Earlier Studies from our lab using non-linear clicks and only contralateral noise • Wide band noise the best suppressors • Narrow band next best • Tones the poorest suppressors • Suppression measured at first in the aggregate using Kemp ILO system substractions.

  5. TEOAE Measurement • “Non-linear” clicks control for stimulus echo artifact. +10dB re: triad above Time

  6. Subsequent studies use… • Low-level (usually 60 dB peak SP) Linear Clicks • Low level noise (usually 65 dB SP) • Forward Masking • Echomaster system for analysis

  7. Or……

  8. Clinical Studies of the MOCS using TEOAEs • …quantification of TEOAE suppression in intensity, frequency and phase using ECHOMASTER (see www. Kresgelab.org) • …results with continuous contralateral noise vs. forward masking paradigms. • …Binaural vs. ipsi vs. contra suppression in forward masking paradigms by intensity, spectral level, correlation and time. • …four click train vs. single click data addressing ipsilateral suppression effects.

  9. How do we quantify EFFERENT SUPPRESSION OF TEOAES in amplitude, frequency and phase. • The Echomaster System shown in action. Designed for ILO systems. • Results expressed in dB, spectral levels, phase and in time segments. • Available free from our Web Page…www.kresgelab.org under Computer Programs, Echomaster. • Designed and Developed by Han Wen (ARO 1992).

  10. Analysis of two like conditions

  11. Comparison of without and with low level contralateral noise

  12. Clinical Studies of the MOCS using TEOAEs • …quantification of TEOAE suppression in intensity, frequency and phase using ECHOMASTER (see www. Kresgelab.org) • …results with continuous contralateral noise vs. forward masking paradigms. • …Binaural vs. ipsi vs. contra suppression in forward masking paradigms by intensity, spectral level, correlation and time. • …four click train vs. single click data addressing ipsilateral suppression effects.

  13. Where we give a single number for Overall Results using low level linear clicks they represent the average data over 8-18 msecs

  14. Predicting the amount of suppression by whether the suppressor is… • Binaural • Ipsilateral • Or Contralateral… to the click stimulus.

  15. TEOAE Suppression

  16. MOCS Emission Suppression as a function of Binaural Noise Duration

  17. Clinical Studies of the MOCS using TEOAEs • …quantification of TEOAE suppression in intensity, frequency and phase using ECHOMASTER (see www. Kresgelab.org) • …results with continuous contralateral noise vs. forward masking paradigms. • …Binaural vs. ipsi vs. contra suppression in forward masking paradigms by intensity, spectral level, correlation and time. • …four click train vs. single click data addressing ipsilateral suppression effects.

  18. Binaural Noise is three times more effective than Contralateral Noise in Suppressing Otoacoustic Emissions (Berlin et al. Hear. Res. 1995)

  19. Clinical Studies of the MOCS using TEOAEs • …quantification of TEOAE suppression in intensity, frequency and phase using ECHOMASTER (see www. Kresgelab.org) • …results with continuous contralateral noise vs. forward masking paradigms. • …Binaural vs. ipsi vs. contra suppression in forward masking paradigms by intensity, spectral level, correlation and time. • …four click train vs. single click data addressing ipsilateral suppression effects.

  20. Does it make a difference if you use a four-click train or a single click? Using A Labview emulation of the ILO88 (Wen et al. ARO) the data are essentially the same.

  21. Temporal Paradigm with one or four linear click onset at 10, 20, 50 and 100 msecs from end of 400 msec white noise Or\ Or.. 400 msecs white noise

  22. Efferent emission suppression by a binaural 400 msec white noise burst preceding an 80 usec pulse

  23. TEOAE Suppression

  24. TEOAE Suppression

  25. More results in MOCS Studies • …Development and Aging • ….Gender and laterality effects…changes in laterality after Fast ForWord™ • … absence of suppression in patients with Auditory Neuropathy. • …patients who are obligate carriers of genes for deafness (See Hood et al Poster later today) Differences in Suppression as well as DPOAE characteristics. • …“tough ears” of musicians. • …medicolegal applications in patients with Hyperacusis • …autistic patients who complain of extreme hearing sensitivity (Berard/Tomatis targets).

  26. Development of Efferent Suppression • Morlet et al., 1993, 1999; Ryan and Piron, 1994; Goforth et al., 1997, 2000 • Efferent suppression is not present at birth in all infants • About 2/3 of term infants show efferent suppression of TEOAEs • Only one-third of pre-term infants demonstrate efferent suppression of TEOAEs

  27. MOCS development of Contralateral Suppression only.Morlet et al.Hearing Research 1999 Under 36 weeks CA, MOCS function appears statistically symmetrical in both ears In older neonates (i.e., CA>36 wks), the suppression is significantly greater the RE than in the LE. This is observed into adulthood.

  28. Aging and Efferent Suppression • Castor et al., 1994 - decreases in contralateral suppression • Hood et al., 1997 - binaural, ipsilateral and contralateral suppression • Suppression decreased as a function of age from 10 to 80 years. • Greatest decreases were observed for binaural suppressors. • These results may be relevant to studies showing a loss of “binaural advantage” with age.

  29. Suppression Versus Age - Right Ear 1.5 kHz Band: Binaural, Ipsilateral and Contralateral Noise

  30. Binaural Right vs. Left Ear Suppression by Age

  31. Ipsilateral Suppression changes with age.

  32. Contralateral suppression declines with age

  33. More results in MOCS Studies • …Development and Aging • ….Gender and laterality effects…changes in laterality after Fast ForWord™ • … absence of suppression in patients with Auditory Neuropathy. • …patients who are obligate carriers of genes for deafness (See Hood et al Poster later today) Differences in Suppression as well as DPOAE characteristics. • …“tough ears” of musicians. • …medicolegal applications in patients with Hyperacusis • …autistic patients who complain of extreme hearing sensitivity (Berard/Tomatis targets).

  34. Right Ear Advantage • The human auditory system shows functional asymmetries, in favor of the right ear. The right ear advantage (REA) especially in Dichotic Listening is usually interpreted as a reflection of the dominance of the left hemisphere for processing speech and language and of the inhibition of ipsilateral auditory pathways. • At the cochlear level, there are significant differences in OAEs (Burns et al., 1992; Kei et al., 1997; Khalfa et al., 1997; Kok et al., 1993; Morlet et al., 1995; Newmark et al., 1997) in adults, infants and both full-term and pre-term neonates. • Asymmetries are observed along the afferent pathways as well as for the efferent fibres. The MOCS appears to be more efficient in RE than in LE (Khalfa and Collet, 1996).

  35. Efferent Suppression Pre-FFW

  36. Efferent Suppression PostFFW

  37. More results in MOCS Studies • …Development and Aging • ….Gender and laterality effects…changes in laterality after Fast ForWord™ • … absence of suppression in patients with Auditory Neuropathy/Dys-synchrony. • …parents who are obligate carriers of genes for deafness(See Hood et al Poster later today) Differences in Suppression as well as DPOAE characteristics. • …“tough ears” of musicians. • …medicolegal applications in patients with Hyperacusis • …autistic patients who complain of extreme hearing sensitivity (Berard/Tomatis targets).

  38. Auditory Neuropathy/Dys-synchrony • Normal Emissions. • No ABR to clicks usually associated with large ringing cochlear microphonic easily discriminated from true neural response by comparing one condensation to one rarefaction click average. • Disturbed speech perception inconsistent with audiogram. • No middle ear muscle reflex. • No MLD • No MOCS suppression.

  39. Patient with profound behavioral deafness but normal emissions.

  40. A normal ABR on the left with click inversion, an Auditory Neuropathy on the right. No click inversion on right.

  41. Rarefaction vs. Condensation click averages Note polarity inversion and no latency shift showing this to be a CM.

  42. Efferent Suppression in Patients with Neural Disorders • Patients with auditory neuropathy/dys-synchrony do not show efferent suppression (Berlin et al., 1993; Starr et al., 1991; 1996). • Patients with 8th nerve tumors who have OAEs show no suppression (Maurer et al., 1992). • Patients with vestibular neurectomy show reduced or no suppression (Williams et al., 1993, 1994). • Patients with Petrous Pyramid Granulomas show no unilateral suppression despite normal emissions (Hurley at al. 2002)

  43. Auditory Neuropathy Patient

  44. AN/AD PATIENTS SHOW VIRTUALLY NO SUPPRESSION

  45. Is this an afferent or efferent failure? • Efferent suppression is present binaurally as long as the good ear is being stimulated, and absent whenever the bad ear is stimulated. • Unilateral AN/AD patients teach us that this is primarily an Afferent failure of synchrony…one of the many reasons we have for suggesting the utility of a semantic index of Auditory Dys-synchrony to describe what effects various etiologies might have in this condition.

  46. More results in MOCS Studies • …Development and Aging • ….Gender and laterality effects…changes in laterality after Fast ForWord™ • … absence of suppression in patients with Auditory Neuropathy. • …patients who are obligate carriers of genes for deafness (See Hood et al Poster later today) Differences in Suppression as well as DPOAE characteristics. • …“tough ears” of musicians. • …medicolegal applications in patients with Hyperacusis • …autistic patients who complain of extreme hearing sensitivity (Berard/Tomatis targets).

  47. DPOAEs in Usher Carriers

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