1. Times Have Changed But Has Our Methodology Jay Jindal BASLP Au.D. HAD BSHAA Professional Development Consultant

2. Acknowledgement Charles Berlin! (For teaching me how to apply the science of audiology into clinical practice and challenge some age-old ideas!)

3. Conflict of interest None

4. Outline Premise and Background Information Otoscopy Tympanometry Acoustic Reflex Testing Otoacoustic Emissions

5. Premise TestTime taken InformationParticular info Otoscopy1 minOuter and Middle ear Ear canal and TM Tympanometry1 minOuter and Middle ear Middle ear Acoustic Reflex (ipsi and contra at 1K and 2KHz) 5 minOuter, Middle, Inner ear, nerve VII, VIII, Brainstem Inner Hair Cells Otoacoustic Emissions 8 minOuter, Middle, Inner ear Outer Hair Cells

6. Human ear-marvel of complex engineering! Detects frequencies of 20Hz to 20,000Hz-wavelength of sound waves ranging from 17mm to 17meter Minimum sound pressure that the ear can detect is 20 micropascal (0dBSPL); and maximum SPL is equivalent to 63 pa (~130dBSPL-threshold of pain), which is approximately 3 million times of min pressure

7. Sensori-Neural Loss: OHC vs IHC OHC- provide a dynamic gain control and enhance sensitivity IHC-provide a channel for transmitting the auditory information to the brain Warr, 1979; Kiang, 1982 Only about 5-10% of the cochlear Ganglion neurons innervate the OHC rest of 90-95% innervate IHC Spoendlin,1966,1969

8. Dawn of Dead (Moore, 2004) Audiometric aspect: mild/moderate/severe/profound Anatomical and physiological aspects: outer and/or inner hair cell damage (Killion & Niquette, 2000;Nelson & Hinojosa, 2006) Note: Hearing thresholds>70dBHL=60% chances of dead region in cochlea (Vinay & Moore, 2007). More still with better low-frequency hearing and steeply sloping hearing loss (Scollie, 2006). However, dead region may also be present in flat severe hearing losses (Moore, 1998; Killen & Munro, 2003). 29% of adults with a moderate to severe hearing loss may have dead regions (Preminger et al, 2005) (Re)defining Hearing Loss! Courtsey: McKinnen, 2006

9. Otoscopy Eardrum Hemorrhagic BlisterHemotympanium (Blood in the Middle Ear)

10. Retracted Ear Drums Courtesy: http://www.entusa.com/eardrum_and_middle_ear.htm

11. Congenital Cholesteotoma The pearly white mass protruding anteriorly from behind the anterior border of the malleus

12. Acquired Cholesteotoma Squamous epithelium growing around the top of a 100% eardrum perforation Cholesteatoma behind the eardrum with granulation tissue in the region of the attic Cholesteatoma in the upper part of the eardrum, with the remainder of the eardrum being normal Cholesteatoma hidden behind granulation tissue covering the attic or superior portion of the eardrum.

13. Glomus Tumour

14. Squamous and Basal Cell Carcinoma

15. iPhone Otoscope-Remotoscope

16. Tympanometry Variants: 1.Low tone (226 Hz) –for "stiffness dominated" systems viz adult middle ear systems 2.High tone tone (678Hz or 1000Hz)- for "mass dominated” system viz newborns under 6 months old 3.Wideband tympanometry and absorbance measures-all age groups Standard tympanometry: a 226 Hz probe tone presented typically at 69 dBHL Instrument measures: 1.How much sound has gone through the system (absorbance) 2.What has remained in the ear canal (reflectance) 3.Pressure peak between +200 and -400dapa pressure change :

17. Uses Middle ear effusion Eustachian tube dysfunction Ossicular discontinuity Perilymph fistula Sometime otoscelerosis Patulous eustachain tube

18. Patulous Eustachian Tube Causes: sudden weight loss, radiation therapy, hormonal changes, pregnancy, fatigue, stress, and inappropriate use of nasal decongestants -Henry, 1993 Procedure: Obtain a baseline tymp and maintain the seal Ask patient to breath slowly Ask them to gradually up the breathing rate You will record sinusoidal-appearing graphic pattern Incidence estimates: 0.3 to 10% of general population Symptoms: often exacerbated by heavy breathing and…… reduced/absent on lying down Autophony, respiratory-synchronous tinnitus, distortion of sounds, hyperacusis, sensation of pressure in ear NB: Volume displacement in tandem with heart beat may indicate glomus tumor in ME

19. 45 year old man with Mild to moderate SNHL bilaterally– Used hearing aids Visited audiology clinic repeatedly, complaining of: – Own voice being very loud/distorted, wind noise in the ears -MRI-NAD -Was sent for repeated moulds, thin tubes, fine-tuning etc. -Symptoms persisted even after 2 years of initial complaint -Termed as a ‘malingerer’ with possible aversion to hearing aids -PET indicated by tymp-confirmed by endoscopy -Cauterised soon after resulting in disappearance of symptoms Case Study

20. Acoustic Reflex It’s a bilateral reflex-when a loud sound enters a normal cochlea, the stapedius muscle will contract on both sides regardless of which ear is stimulated This is below the level of cognitive control Facial nerve innervates the stapedius muscle! Figure from Diana C. Emanuel, 2009; Audiologyonline.com

21. Uses of AR Diagnostic value- when the tymp machine fails you: -Stapes fixation -?Middle ear effusion (flat trace on screening tymp-use diagnostic tymp where possible) Can also be absent if there is: -Negative middle ear pressure -Facial nerve dysfunction

22. Acoustic reflex when we talk! Sound pressure level in mouth while vocalizing /a/ is of order of 110dBA-sufficient intensity to elicit stapedial reflex, which reduces the vocal sound intensities reaching the inner ear by approximately 20 decibels. (Moller, A, 2000) ART might also give you the upper limit to the MPO (SSPL-90) of the hearing aids, as the operating theory is that you do not want the instruments to constantly trigger the stapedial muscle reflex, as it may cause fatigue to the patient (Jay B, 2008)

23. Role of IHC in AR Only about 5-10% of the cochlear ganglion neurons innervate the OHC rest of 90-95% innervate IHC (Spoendlin,1966,1969) If IHC are not intact-AR testing will be abnormal (Charles Berlin, 1998) Audiological myth-Born without a stapedial muscle : Charles Berlin reports that, as a postdoctoral student at Johns Hopkins, he evaluated almost 800 temporal bones. Of those, every one had a stapedial muscle.

24. AR and ANSD

25. Otoacoustic Emissions

26. Vs Cochlea: -About 32mm length -With 16,000-20,000 hair cells -Resolves about 1500 separate pitches This would require a separate detectable pitch for every 0.02 mm, which is physically unreasonable for a simple peaking action on the membrane. So, some pitch sharpening mechanism must be operating?

27. OHC Electro-motility 1.Hair cells have a resting potential of about - 70mV 2.Deflection of sterocillia leads to flow of K + ions into OHC-’mechanoelectrical transduction’ 3.This generates a ‘receptor potential’ within the hair cell 4.Changes in voltage across plasma membrane leads to OHC length alteration-electromotility 5.This triggers ‘active’ process within cochlea- enhancing the stimulus otherwise dampened by the mass of cochlear fluid

28. Outer Hair Cells can be tested with two procedures Inner Hair Cells can be tested with three procedures: 1. Otoacoustic Emissions. 2. Cochlear microphonics using insert earphones and reversing the polarity of the click at least once at the end of a completed average. 1. EcochG 2. ABR 3. MIDDLE EAR MUSCLE REFLEXES. If these are absent or elevated above 95dB HL, in the presence of normal emissions, it warrants further careful investigation (Berlin, Hood et al. 2005)

29. Thank you! Jay Jindal BASLP Au.D. education@bshaa.com