Clinical Studies of Medial Olivocochlear Function Charles I

Clinical Studies of Medial Olivocochlear Function Charles I. Berlin, Ph. D Linda Hood Ph. D Thierry Morlet, Ph. D 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.

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.

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

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.

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

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

Or……

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.

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 d. B, 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).

Analysis of two like conditions

Comparison of without and with low level contralateral noise

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.

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

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

TEOAE Suppression

MOCS Emission Suppression as a function of Binaural Noise Duration

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.

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

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.

Does it make a difference if you use a four-click train or a single click? Using A Labview emulation of the ILO 88 (Wen et al. ARO) the data are essentially the same.

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

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

TEOAE Suppression

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

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

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.

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.

Suppression Versus Age - Right Ear 1. 5 k. Hz Band: Binaural, Ipsilateral and Contralateral Noise

Binaural Right vs. Left Ear Suppression by Age

Ipsilateral Suppression changes with age.

Contralateral suppression declines with age

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

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).

Efferent Suppression Pre-FFW

Efferent Suppression Post. FFW

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

Auditory Neuropathy/Dyssynchrony • 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.

Patient with profound behavioral deafness but normal emissions.

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

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

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 8 th 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)

Auditory Neuropathy Patient

AN/AD PATIENTS SHOW VIRTUALLY NO SUPPRESSION

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 Dyssynchrony to describe what effects various etiologies might have in this condition.

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

DPOAEs in Usher Carriers

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

Musicians in the LPO • Have Binaural Suppression of 4 -7 d. B in contrast to 2 -to-3 d. B in age-matched normals. • May differ by instrument (eg violinists and left ears. ) • Preliminary data funded by “Grammy” group, collected by S. Brashears.

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

Suppression and Hyperacusis

Efferent Suppression in Hyperacusics

More results in MOCS Studies • …Development and Aging • …. Gender and laterality effects…changes in laterality after Fast For. Word™ • … 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).

Efferent Suppression in Hyperacusics vs Autistics

Berlin CI, Hood LJ, Hurley A, Wen H. 1994. Contralateral suppression of otoacoustic emissions: An index of the function of the medial olivocochlear system. Otolaryngol. Head Neck Surg 100: 3 -21. Berlin CI, Hood, LJ, Hurley A, Wen H, Kemp DT. 1995. Binaural noise suppresses click-evoked otoacoustic emissions more than ipsilateral or contralateral noise. Hear Res 87: 96 -103. Hood LJ, Berlin CI, Hurley A, Wen H. 1996. Suppression of otoacoustic emissions in normal hearing individuals. Chapter in Berlin CI (Ed), Hair Cells and Hearing Aids. San Diego: Singular Press. Hood LJ, Berlin CI, Hurley A, Cecola RP, Bell B. 1996. Contralateral suppression of click-evoked otoacoustic emissions: Intensity effects. Hear Res 101: 113 -118. Hood LJ, Berlin CI, Goforth-Barter L, Bordelon J, Wen H. 1999. Recording and analyzing efferent suppression of transient-evoked otoacoustic emissions. In Berlin CI: The Efferent Auditory System. San Diego: Singular Publishing Group. Hood LJ, Berlin CI. 2001. Efferent suppression in patients with auditory neuropathy. In Starr A and Sininger YS. Auditory Neuropathy. San Diego: Singular Publishing Group. Wen H, Berlin C, Hood L, Jackson D, Hurley A. 1993. A program for quantification and analysis of transient evoked otoacoustic emissions. ARO Abstracts 16: 102. Hood LJ, Berlin CI, Wakefield L, Hurley A. 1995. Noise duration affects suppression of transient-evoked otoacoustic emissions. ARO Abstracts 19: 123. Goforth L, Hood LJ, Berlin CI. 1997. Efferent suppression of transient-evoked otoacoustic emissions in human infants. ARO Abstracts , 20: 166. Hood LJ, Hurley AE, Goforth L, Bordelon J, Berlin CI. 1997. Aging and efferent suppression of otoacoustic emissions. ARO Abstracts , 20: 167. Hood LJ, Goforth L, Bordelon J, Hurley A, Berlin CI. 1998. Suppression of transient evoked otoacoustic emissions using frequency limited stimuli. ARO Abstracts , 21: 153. Goforth L, Hood LJ, Berlin CI. 1998. Development of efferent function in neonates. ARO Abstracts , 21: 152. Berlin CI, Goforth-Barter L, Hood LJ. 1998. Some hyperacusics show abnormally strong efferent suppression of TEOAEs. ARO Abstracts , 21: 153. Hood LJ, Berlin CI, Bordelon J, Goforth-Barter L, Hurley A, Tedesco S. 2000. Patients with auditory neuropathy lack efferent suppression of evoked otoacoustic emissions. ARO Abstracts 23. Hood LJ, Berlin CI, Tedesco S, Brashears S, Jeanfreau J, Keats B, Morlet T. 2001. Otoacoustic emissions in carriers of genes for hearing loss. ARO Abstracts 24.

Thanks to other collaborators not listed as full co-authors, including Kelly Rose, Leah Barter, Han Wen, and Pat Cecola MD. This entire presentation will be available on our Web Page. • www. kresgelab. org