Objectives: To establish that admittance (Y) and susceptance (B) conductance (G) tympanograms at 2 kHz can reflect the status of the annular ligament and the cochlear pressure. Methods: Seven experiments were set up in 22 guinea pigs: ventilation of the bulla, blockage of the stapes and round window membrane (RWM), fistula, fluid removal from the cochlea, injection of saline in the scala tympani and acoustic trauma. Resonance frequency, Y, B and G at 2 kHz and curve shapes were analyzed before and after lesions. Results: A supplementary peak was observed in Y/G tympanograms in all RWM fistulas and in some cases of acoustic trauma; injection of saline into the scala tympani induced constant, immediate and reproducible changes; RWM and stapes blockages induced foreseeable peaking at 2 kHz; fluid removal from the cochlea induced multiple peak curves. Conclusion: Experimentally induced modifications at the AL result in noticeable, constant and reproducible changes in tympanogram curves at 2 kHz and seem to reflect inner ear pressure.

Keywords:
Multifrequency tympanometry, Tympanometry, Impedance audiometry, Cochlea, Perilymphatic fistula, Acoustic trauma
1.
Avan P, Büki B, Dordain M, Wit P: Middle ear influence on otoacoustic emissions. I. Noninvasive investigation of the human transmission apparatus and comparison with model results. Hear Res 2000;140:189–201.
2.
Camicas van Gout M: Théorie acoustico-mécanique: localisation des sources sonores. Rev Laryngol Otol Rhinol 1994;115:13–20.
3.
Camicas van Gout M, Negrevergne M: Impédancemétrie multifréquentielle et exploration des surdités professionnelles. Un nouveau test «le Teflag». Rev Laryngol Otol Rhinol 1996;117:399–407.
4.
Colletti V: Tympanometry from 200 to 2000 Hz probe tone. Audiology 1976;15:106–119.
5.
Creten WL, Vanpaeperstraete PM, Van Camp KJ: Impedance and admittance tympanometry I. Experimental approach. Audiology 1978;17:97–107.
6.
Dancer A, Franke R: Biomécanique de l’oreille moyenne. Rev Laryngol Otol Rhinol 1995;116:5–12.
7.
De Jonge R: Normal tympanometric gradient. A comparison of three methods. Audiology 1986;25:299–308.
8.
Hanks WD, Rose KJ: Middle ear resonance and acoustic immittance measures in children. J Speech Hear Res 1993;36:218–222.
9.
Holte L, Margolis RH, Cavanagh RM: Developmental changes in multifrequency tympanograms. Audiology 1991;30:1–24.
10.
Koebsell K, Margolis RH: Tympanometric gradient measured from normal pre-school children. Audiology 1986;25:149–157.
11.
Liden G, Bjorkman G, Nyman H, Kunov H: Tympanometry and acoustic impedance. Acta Otolaryngol (Stockh) 1977;83:140–145.
12.
Liden G, Harford E, Hallen O: Tympanometry for the diagnosis of ossicular disruption. Arch Otolaryngol 1974;99:23–29.
13.
Lutman ME: Phasor admittance measurements of the middle ear. I. Theoretical approach. Scand Audiol 1984;13:253–264.
14.
Lutman ME, Martin AM: Development of an electroacoustic analogue model of the middle ear and acoustic reflex. J Sound and Vibration 1979;64:133–157.
15.
Lynch TJ, Nedzelnitsky V, Peake WT: Input impedance of the cochlea in cat. J Acoust Soc Am 1982;72:108–130.
16.
Manley GA, Johnstone BM: Middle-ear function in the guinea pig. J Acoust Soc Am 1974;56:571–576.
17.
Margolis RH: Impedance screening for middle ear disease in children; in Harford ER, Bess FH, Bluestone CD, Klein JO (eds): Tympanometry in Infants. State of the Art. New York, Grune and Stratton, 1978, pp 52–72.
18.
Margolis RH, Goycoolea HG: Multifrequency tympanometry in normal adults. Ear Hear 1993;14:408–413.
19.
Margolis RH, Osguthorpe JD, Popelka GR: The effects of experimentally produced middle ear lesions on tympanometry in cats. Acta Otolaryngol (Stockh) 1978;86:428–436.
20.
Margolis RH, Popelka GR: Static and dynamic acoustic impedance in infant ears. J Speech Hear Res 1975;18:435–438.
21.
Margolis RH, Popelka GR: Interactions among tympanometric variables. J Speech Hear Res 1977;20:447–452.
22.
Margolis RH, Schachern PL, Hunter LL, Sutherland C: Multifrequency tympanometry in chinchillas. Audiology 1995;34:232–247.
23.
Merchant SN, Ravicz ME, Rososwski JJ: Acoustic input impedance of the stapes and cochlea in human temporal bones. Hear Res 1996;97:30–45.
24.
Nuttal AL: Measurements of the guinea pig middle ear transfer characteristic J Acoust Soc Am 1974a;56:1231–1238.
25.
Nuttal AL: Tympanic muscle effects on middle ear transfer characteristic. J Acoust Soc Am 1974b;56:1239–1247.
26.
Ravicz M, Rosowski JJ, Voigt HF: Sound-power collection by the auditory periphery in the Mongolian gerbil Meriones unguiculatus. Middle-ear input impedance. J Acoust Soc Am 1992;92:157–177.
27.
Shinomori Y, Spack DS, Jones DD, Kimura RS: Volumetric and dimensional analysis of the guinea pig inner ear. Ann Otol Rhinol Laryngol 2001;110:91–98.
28.
Shurin PA, Pelton SI, Klein JO: Otitis media in the newborn infant. Am Otol Rhinol Laryngol 1976;85(suppl 25)2:16–222.
29.
Valvik BR, Johnsen M, Laukli E: Multifrequency tympanometry. Audiology 1994;33:245–253.
30.
Van Camp KJ, Shanks JE, Margolis RH: Stimulation of pathological high-impedance tympanograms. J Speech Hear Res 1986;29:505–514.
31.
Van Camp KJ, Vanhuyse VJ, Creten WL, Vanpeperstraete PM: Impedance and admittance tympanometry II: mathematical approach. Audiology 1978;17:108–119.
32.
Vanhuyse VJ, Creten WL, Van Camp KJ: On the W-notching of tympanograms. Scan Aud 1975;8:173–179.
33.
Zwislocki J: Analysis of the middle ear function. II. Guinea pig ear. J Acoust Soc Am 1963;35:1034–1040.
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2006
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