{ "id": "ep4m6qevgh", "slug": "tympanometry", "title": "Tympanometry", "updated": "2026-10-25", "topic_path": [ { "id": "life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/topics/life" }, { "id": "life.health", "label": "Human health and medicine", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health" }, { "id": "life.health.clinical", "label": "Clinical assessment and procedures", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical" }, { "id": "life.health.clinical.clinical-diagnostics", "label": "Diagnosis and clinical assessment", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical.clinical-diagnostics" }, { "id": "life.health.clinical.clinical-diagnostics.audiology-and-hearing-assessment", "label": "Audiology and hearing assessment", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical.clinical-diagnostics.audiology-and-hearing-assessment" } ], "geo": [ { "id": "geo.nongeo.t1946.life.health.clinical.clinical-diagnostics", "label": "Non-geographic · 1946 to 2000: Diagnosis and clinical assessment", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical.clinical-diagnostics", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1946", "label": "Non-geographic · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946" }, { "id": "geo.nongeo.t1946.life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life" }, { "id": "geo.nongeo.t1946.life.health", "label": "Human health and medicine", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health" }, { "id": "geo.nongeo.t1946.life.health.clinical", "label": "Clinical assessment and procedures", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical" }, { "id": "geo.nongeo.t1946.life.health.clinical.clinical-diagnostics", "label": "Diagnosis and clinical assessment", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical.clinical-diagnostics" } ] } ], "excerpt": "Tympanometry is a clinical test measuring middle ear admittance while ear canal pressure varies, producing a tympanogram used to detect fluid, eustachian tube dysfunction, and eardrum perforation.", "snippet": "Tympanometry is a clinical test measuring middle ear admittance while ear canal pressure varies, producing a tympanogram used to detect fluid, eustachian tube dysfunction, and eardrum perforation.", "node": "life.health.clinical.clinical-diagnostics.audiology-and-hearing-assessment", "markdown": "# Tympanometry\n\nTympanometry is a clinical test that measures the acoustic admittance of the middle ear while air pressure in the sealed ear canal is varied, producing a trace (the tympanogram) that shows how freely the eardrum moves. It is used to detect middle ear fluid, eustachian tube dysfunction, ossicular problems, and eardrum perforation.[1](https://www.aafp.org/afp/2004/1101/p1713) • [2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf)\n\n| Key fact | Detail |\n|---|---|\n| What is measured | Peak compensated static admittance (Ytm), tympanometric peak pressure (TPP), equivalent ear canal volume (ECV), and tympanometric width[1](https://www.aafp.org/afp/2004/1101/p1713) |\n| Standard probe tone | 226 Hz for ages 6 months and older; 1000 Hz below 6 months corrected age[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) |\n| Normal adult peak admittance | 0.3 to 1.6 mmho[3](http://www.interacoustics.com/academy/tympanometry-training/traditional-tympanometry/tympanometry) |\n| Normal adult peak pressure | −50 to +50 daPa[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) |\n| Diagnostic accuracy for OME | Pooled sensitivity 84 (95% CI 82–86) and specificity 79 (95% CI 76–83)[4](https://link.springer.com/article/10.1186/s43163-024-00571-y) |\n| First tympanogram | Terkildsen and Thomsen, 1959[5](https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/abs/influence-of-pressure-variations-on-the-impedance-of-the-human-ear-drum/7790878D13A7EF3D072069C6C7968BD1) |\n| Classification | Jerger types A, As, Ad, B, and C[6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf) |\n\n## How it works\n\nA tympanometer measures admittance, the ease of acoustic flow, which is the reciprocal of impedance (\\( Y = 1/Z \\)).[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) [Admittance](https://www.edgepedia.org/admittance) is the complex reciprocal of impedance: if \\( Z = R + jX \\), then \\( Y = G + jB = 1/Z \\), with \\( G = R/(R^2 + X^2) \\) and \\( B = -X/(R^2 + X^2) \\).[7](https://grason-stadler.com/education/guides/tympanometry-basics) Acoustic resistance reflects energy dissipated by friction and cochlear consumption, while reactance combines mass (ossicles, perilymph) and stiffness (ligaments, tendons, tympanic membrane, enclosed air).[7](https://grason-stadler.com/education/guides/tympanometry-basics)\n\nThe probe tone is a low-frequency sound delivered into the sealed canal. At 226 Hz the normal middle ear acts as a stiffness-controlled system, so susceptance approximately equals total admittance, which allows admittance to be expressed as an equivalent volume of air. The 226 Hz convention exists because at this frequency 1 mmho (1 acoustic mmho = \\( 10^{-8} \\ \\mathrm{m^3/(Pa \\cdot s)} \\)) equals the admittance of a 1 cm\\(^3\\) volume of air at sea level and 20 °C.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) • [8](https://www.asha.org/policy/rp1988-00027/) • [7](https://grason-stadler.com/education/guides/tympanometry-basics)\n\nVarying the static pressure in the sealed canal changes the impedance at the eardrum. Terkildsen and Thomsen proposed that a pressure of 200 daPa places the eardrum under considerable tension so that, in theory, all probe-tone energy is reflected at the eardrum and the measured admittance is that of the ear canal alone.[6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf) This compensation assumption lets the instrument subtract the canal component and report peak compensated static admittance, a direct index of eardrum and middle ear mobility.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) At the resonance frequency, stiffness and mass reactances are equal in magnitude; below resonance stiffness dominates, and above resonance mass dominates, so the system becomes mass-controlled and notching appears in the trace; pathology shifts the resonant point.[7](https://grason-stadler.com/education/guides/tympanometry-basics)\n\n## How it is done\n\nThe instrument has five basic elements: a display, a pump, a microphone, a speaker, and a probe with a sealing tip. The probe sealed in the external auditory meatus contains a driver that produces the probe tone, a microphone that monitors sound pressure in the enclosed canal, and a port for the pneumatic system; admittance is derived from the electrical current an automatic gain control circuit needs to hold sound pressure constant.[3](http://www.interacoustics.com/academy/tympanometry-training/traditional-tympanometry/tympanometry) • [8](https://www.asha.org/policy/rp1988-00027/)\n\nTympanometry must be preceded by otoscopy, and acoustic reflex threshold measurements must be preceded by tympanometry.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) After sealing the probe tip, the pump sweeps pressure from positive to negative. The BSA recommends a slow sweep of 50 daPa/s or less, tracking from +200 daPa to at least −400 daPa (preferably −600 daPa), with screening sweeps up to 600 daPa/s.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) Typical commercial pump range is −600 to +300 daPa, with the highest pressure used to estimate ear canal volume.[3](http://www.interacoustics.com/academy/tympanometry-training/traditional-tympanometry/tympanometry) Standards require calibration cavities of 0.5, 2.0, and 5.0 cm\\(^3\\), and Type 1 and 2 instruments must sweep between +200 and −600 daPa with pressure accuracy within ±10 daPa or ±10%, whichever is greater.[8](https://www.asha.org/policy/rp1988-00027/) Contraindications include ear pain, a bulging or inflamed eardrum, visible perforation, discharge, foreign objects, ear surgery within two months, and a programmable VP shunt.[9](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf)\n\nThe classical 226 Hz tympanogram is interpreted with Jerger's shape-based classification, which produced categories A, B, and C in 1970, later expanded to include As and Ad:[10](https://www.ovid.com/jnls/hbcm/fulltext/10.4103/hbc.hbc_40_25~from-conventional-tympanometry-to-pressure-less-acoustic) • [11](https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0043-1764139.pdf)\n\n- **Type A**: a peak near 0 daPa, normal middle ear function.\n- **Type As**: a shallow peak, suggesting a stiff system such as ossicular fixation ([otosclerosis](https://www.edgepedia.org/otosclerosis)).[6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf)\n- **Type Ad**: a deep peak, suggesting ossicular discontinuity, monomeric membrane, or atrophic scarring.[6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf) • [1](https://www.aafp.org/afp/2004/1101/p1713)\n- **Type B**: a flat trace. With normal ECV it usually indicates middle ear effusion; with high ECV, perforation or a patent grommet; with low ECV, a probe blocked by wax or incorrectly placed.[9](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf)\n- **Type C**: negative peak pressure, indicating eustachian tube dysfunction.[9](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf) • [6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf)\n\nThe tympanometer also yields four quantitative measures: equivalent ear canal volume, static admittance (peak compliance), tympanometric peak pressure, and tympanometric width or gradient.[1](https://www.aafp.org/afp/2004/1101/p1713) For adults, normal peak admittance is 0.3 to 1.6 mmho, peak pressure −50 to +50 daPa, and ECV 0.6 to 2.5 ml; for children, peak pressure −100 to +50 daPa and ECV 0.4 to 1.0 ml have been reported.[3](http://www.interacoustics.com/academy/tympanometry-training/traditional-tympanometry/tympanometry) Published sources give different pediatric peak pressure ranges, so local normative data should govern interpretation. Tympanometric width is optimally calculated as the pressure interval at a 50% reduction in compensated peak admittance,[8](https://www.asha.org/policy/rp1988-00027/) a method developed from work by Katherine Koebsell and Robert Margolis on normal preschool children.[12](https://doi.org/10.3109/00206098609078381) Two caveats apply: TPP can overestimate true middle ear pressure by 30 to 70 daPa, and tympanometry can overestimate ear canal volume by as much as 24 to 39%.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf)\n\n## Origin\n\nThe first systematic study of the acoustic impedance of the human ear was made by Tröger in 1930, and such measurements were introduced into clinical work with a mechanical acoustic bridge.[13](https://europepmc.org/article/MED/13837466) • [11](https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0043-1764139.pdf) Zwislocki reported acoustic impedance measurements on normal and pathological ears in 1957, developing an acoustic bridge that measured resistance and reactance at various frequencies.[14](https://pmc.ncbi.nlm.nih.gov/articles/PMC4906304/) • [15](https://doi.org/10.1121/1.1908776)\n\nIn 1959, K. Terkildsen and K. A. Thomsen published \"The Influence of Pressure Variations on the Impedance of the Human Ear Drum\" in The Journal of Laryngology & Otology, subtitled \"A method for Objective Determination of the Middle-Ear Pressure\"; this described the first pressure-varying impedance measurement, the first tympanogram.[5](https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/abs/influence-of-pressure-variations-on-the-impedance-of-the-human-ear-drum/7790878D13A7EF3D072069C6C7968BD1) • [6](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf) The paper \"An electroacoustic impedance measuring bridge for clinical use\" was published in Archives of Otolaryngology.[13](https://europepmc.org/article/MED/13837466) Their work produced the first commercially available electroacoustic impedance bridge, the Madsen ZO70, in 1961.[11](https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0043-1764139.pdf) Routine clinical use dates from the early 1970s.[8](https://www.asha.org/policy/rp1988-00027/)\n\n## Variants\n\nIn newborns the dominant impedance component is mass rather than stiffness, and the ear canal diameter may change by as much as 70% under tympanometric pressure, so 226 Hz results can be inconsistent with the clinical condition.[16](https://www.sciencedirect.com/science/article/pii/S016558762100197X) The compensation scheme is inaccurate in infants, whose soft cartilaginous canal walls expand and contract with static pressure.[14](https://pmc.ncbi.nlm.nih.gov/articles/PMC4906304/) The BSA therefore recommends 1000 Hz for service users below 6 months corrected age and 226 Hz from 6 months.[2](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf) For 1000 Hz tympanograms in infants there is no normative admittance range in general use: a positive peak is normal, whereas a flat or trough-shaped peak is abnormal and suggests effusion.[9](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf) In one newborn comparison, mean static compliance at 1000 Hz was three times higher than at 226 Hz, and the authors concluded 1000 Hz is the better frequency for newborns.[16](https://www.sciencedirect.com/science/article/pii/S016558762100197X) Multifrequency tympanometry was reported by V. Colletti in 1977,[17](https://doi.org/10.3109/00206097709071839) and 1000 Hz norms for newborns were published by Robert H. Margolis and colleagues in 2003.[18](https://doi.org/10.1055/s-0040-1715757)\n\nWideband tympanometry (WBT) measures absorbance, admittance, and phase angle from 226 to 8000 Hz while ear canal pressure varies from +200 to −400 daPa, and can be performed at ambient pressure, making it usable in young infants because it is unaffected by the floppy canal wall.[4](https://link.springer.com/article/10.1186/s43163-024-00571-y) Lower resonant frequency indicates a more compliant system (ossicular discontinuity, large perforations), and higher resonant frequency indicates increased stiffness (early otosclerosis, ossicular fixation); the direction for effusion depends on the measurement method, and one wideband study diagnosed OME with a resonant-frequency cutoff of ≤545.5 Hz.[10](https://www.ovid.com/jnls/hbcm/fulltext/10.4103/hbc.hbc_40_25~from-conventional-tympanometry-to-pressure-less-acoustic) Pressure-less acoustic immittance (PLAI) measures complex admittance \\( Y(f) \\) in an open ear canal at ambient pressure with no sealed probe or pressure sweep, completing in a few seconds per ear.[10](https://www.ovid.com/jnls/hbcm/fulltext/10.4103/hbc.hbc_40_25~from-conventional-tympanometry-to-pressure-less-acoustic) Machine-learning classification is emerging: the 2026 WAIHybrid study achieved a macro-F1 of 87.76% and a balanced accuracy of 88.07% on an external clinical dataset of 206 ear-level records.[19](https://iopscience.iop.org/article/10.1088/2057-1976/ae885d/pdf)\n\n## Applications\n\nA meta-analysis of seven studies reported tympanometry sensitivity of 84 (95% CI 82–86) and specificity of 79 (95% CI 76–83) for otitis media with effusion.[4](https://link.springer.com/article/10.1186/s43163-024-00571-y) The positive predictive value of a flat type B tympanogram for effusion is between 49 and 99 percent according to AHRQ guidelines.[1](https://www.aafp.org/afp/2004/1101/p1713) In children with otitis media, wideband resonant frequency showed sensitivity of 90.3%, specificity of 91.2%, and accuracy of 90.7% for diagnosing OME at a cutoff of ≤545.5 Hz.[4](https://link.springer.com/article/10.1186/s43163-024-00571-y) Pan and Yang reported WBT sensitivity and specificity for effusion of 94.8% and 87.5%, higher than conventional tympanometry (91.3% and 62.5%).[4](https://link.springer.com/article/10.1186/s43163-024-00571-y)\n\n## Limitations and alternatives\n\nDevice error messages flag most mechanical failures: \"BLOCKED\" indicates improper probe insertion or cerumen occlusion, \"OPEN\" indicates an inadequate seal or perforation, and \"LEAK\" indicates the device could not reach the desired pressures.[1](https://www.aafp.org/afp/2004/1101/p1713) An abnormally small ECV (below 0.5 cm\\(^3\\) in adults) suggests [impacted cerumen](https://www.edgepedia.org/impacted-cerumen) or a probe seal against the canal wall; an abnormally large ECV (above 2.5 cm\\(^3\\) in adults or 2.0 cm\\(^3\\) in children) suggests perforation or a patent pressure equalization tube.[8](https://www.asha.org/policy/rp1988-00027/) Movement, talking, swallowing, or sucking causes artifact in the recording.[9](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf)\n\nClinically, tympanometry usually cannot differentiate acute otitis media from otitis media with effusion, both of which may produce a flat type B curve with normal ECV, and a flat trace can also reflect tympanosclerosis, cholesteatoma, middle ear tumor, or eardrum scarring, usually with the ECV interpreted separately.[1](https://www.aafp.org/afp/2004/1101/p1713) Conventional tympanometry is unreliable in young infants for the reasons described above.[1](https://www.aafp.org/afp/2004/1101/p1713) In a systematic review of eight diagnostic methods for middle ear effusion, pneumatic otoscopy had the best apparent performance, with pooled sensitivity of 94% (95% CI 92–96%) and specificity of 80% (95% CI 75–86%).[20](https://www.ncbi.nlm.nih.gov/books/NBK70068/) The AAP/AAFP/AHRQ guideline accordingly makes pneumatic otoscopy the primary diagnostic tool for OME, with tympanometry optional for confirming suspected cases; the two tests are complementary.[1](https://www.aafp.org/afp/2004/1101/p1713)\n\n## References\n\n1. [Tympanometry | AFP (American Family Physician, 2004)](https://www.aafp.org/afp/2004/1101/p1713)\n2. [BSA Recommended Procedure: Tympanometry & Acoustic Reflex Thresholds (March 2026 minor revision)](https://www.thebsa.org.uk/wp-content/uploads/2026/03/BSA-Recommended-Procedure-Tympanometry-Acoustic-Reflex-Thresholds-March-2026-minor-revision.pdf)\n3. [Tympanometry: An Introduction (Interacoustics Academy)](http://www.interacoustics.com/academy/tympanometry-training/traditional-tympanometry/tympanometry)\n4. [Wideband tympanometry in otitis media (Egyptian Journal of Otolaryngology, 2024)](https://link.springer.com/article/10.1186/s43163-024-00571-y)\n5. [The Influence of Pressure Variations on the Impedance of the Human Ear Drum: A method for Objective Determination of the Middle-Ear Pressure](https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/abs/influence-of-pressure-variations-on-the-impedance-of-the-human-ear-drum/7790878D13A7EF3D072069C6C7968BD1)\n6. [Handbook of Clinical Audiology, Chapter 9 (Tympanometry)](https://downloads.lww.com/wolterskluwer_vitalstream_com/sample-content/9780781781060_katz/samples/chapter_9.pdf)\n7. [Tympanometry Basics (Grason-Stadler Testing Guides)](https://grason-stadler.com/education/guides/tympanometry-basics)\n8. [Tympanometry (ASHA Recommended Practices RP1988-00027)](https://www.asha.org/policy/rp1988-00027/)\n9. [Tympanometry, Child and Adolescent Health Service (Western Australia) guideline](https://cahs.health.wa.gov.au/~/media/HSPs/CAHS/Documents/Community-Health/CHM/Tympanometry.pdf)\n10. [From conventional tympanometry to Pressure-Less Acoustic Immittance (Hearing Balance and Communication, 2025)](https://www.ovid.com/jnls/hbcm/fulltext/10.4103/hbc.hbc_40_25~from-conventional-tympanometry-to-pressure-less-acoustic)\n11. [The Rise and Fall of Aural Acoustic Immittance](https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0043-1764139.pdf)\n12. [Katherine Koebsell, Robert Margolis (1986). Tympanometric Gradient Measured from Normal Preschool Children. International Journal of Audiology.](https://doi.org/10.3109/00206098609078381)\n13. [An electroacoustic impedance measuring bridge for clinical use](https://europepmc.org/article/MED/13837466)\n14. [Acoustic Immittance, Absorbance, and Reflectance in the Human Ear Canal](https://pmc.ncbi.nlm.nih.gov/articles/PMC4906304/)\n15. [J. Zwislocki (1957). Some Impedance Measurements on Normal and Pathological Ears. The Journal of the Acoustical Society of America.](https://doi.org/10.1121/1.1908776)\n16. [Comparison of tympanometry results for probe tones of 226 Hz and 1000 Hz in newborns](https://www.sciencedirect.com/science/article/pii/S016558762100197X)\n17. [V. Colletti (1977). Multifrequency Tympanometry. International Journal of Audiology.](https://doi.org/10.3109/00206097709071839)\n18. [Robert H. Margolis and colleagues (2003). Tympanometry in Newborn Infants, 1 kHz Norms. Journal of the American Academy of Audiology.](https://doi.org/10.1055/s-0040-1715757)\n19. [Simulation-driven deep learning for the diagnosis of middle ear pathologies using wideband acoustic immittance (Biomedical Physics & Engineering Express, 2026)](https://iopscience.iop.org/article/10.1088/2057-1976/ae885d/pdf)\n20. [Evidence assessment of the accuracy of methods of diagnosing middle ear effusion in children with OME (Takata et al., Pediatrics 2003; DARE abstract)](https://www.ncbi.nlm.nih.gov/books/NBK70068/)\n\n---\n*Topic: Encyclopedia › Life and health › Human health and medicine › Clinical assessment and procedures › Diagnosis and clinical assessment › Audiology and hearing assessment*\n\n*Initially written Sep 29, 2026 · Edited: Oct 15, 2026; Oct 25, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/tympanometry", "markdown_url": "https://www.edgepedia.org/tympanometry.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. 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