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TYMPANOMETRY · ACOUSTIC REFLEX · INTERACTIVE TOOL

Acoustic Immittance Simulator

Read the ENT note the patient hands you, choose a suitable probe tip, seal the ear canal and start the measurement yourself. Read the ear canal volume, static compliance and peak pressure from the tympanogram; find the ipsilateral and contralateral reflex thresholds and, when needed, add reflex decay and Eustachian tube tests. While the measurement runs, watch the movement of the eardrum, the ossicles and the stapedius muscle in the live middle ear cross-section. When you finish, your interpretation is compared with the expected answers.

Works on computers and tablets · the 3D scene needs an up-to-date browser

  • 17 clinical cases
  • 3 practice modes
  • 226 · 678 · 1000 Hz
  • Ipsi + contra reflex
  • Reflex decay
  • Eustachian tube tests

Before you start

Four short notes to help you use the simulator smoothly.

Computer or tablet

The 3D room, the middle ear cross-section and the device screen must be visible at the same time. For this reason, it does not open on a phone screen; hold your tablet in landscape.

The first load takes a few seconds

The patient and clinician models load with the page. 3D rendering needs an up-to-date browser that supports WebGL.

Sound is optional

The pump, probe tone and reflex stimulus play at a low level; speech is shown in written speech bubbles with short syllable sounds. You can turn the sound off with the button in the top bar.

For educational use

This is a simulation; it does not replace a clinical diagnostic tool or a calibrated immittance meter. The values are generated from a virtual patient.

How does it work?

The flow of a real immittance session: prepare the patient, measure both ears, complete the reflexes, interpret the findings.

  1. 1

    Choose the case and the mode

    Choose one of the 17 clinical cases or the blind case. Set the patient's cooperation (good or variable) and the practice mode (Learning, Guided, Field), then go to the room.

  2. 2

    Prepare the patient

    The ENT note the patient hands you gives the history and the otoscopy finding; you decide which tests to perform. Read out the instructions, choose a probe tip from the box by trying them, and check that the canal is sealed.

  3. 3

    Measure

    Perform tympanometry in both ears; search for reflexes at peak pressure in the ipsi and contra pathways, and confirm the threshold 5 dB above it. Add the reflex decay test and the Eustachian tube tests if needed.

  4. 4

    Interpret and compare

    For each ear, interpret the tympanogram type and the likely diagnosis, the four reflex pathways and the reflex pattern. Your answers are compared item by item with the expected answers and scored.

Cases

17 cases ordered by difficulty, from a normal middle ear to a brainstem lesion. Each time you open a case, a new patient is generated: the values, the affected side and the canal diameter change, so you will not see the same numbers when you repeat a case.

Easy
Normal middle ear and hearingA starter case for getting to know the method and the device.
Easy
Fluid in the middle earIn one or both ears; the shape of the curve is read together with the volume.
Easy
Negative middle ear pressureBlocked ear after a flight; the position of the peak pressure matters.
Easy
Tympanic membrane perforationThe curve is flat; the real clue is in the ear canal volume.
Easy
Ventilation tubeIs the tube patent? Compare the volumes of the two ears.
Easy
Cerumen impactionWhat does the curve measure when something blocks the probe?
Moderate
OtosclerosisSlowly progressive loss; the shallow curve and the reflex findings are interpreted together.
Moderate
Ossicular chain discontinuityReduced hearing after a blow; the height of the curve stands out.
Moderate
Lax (flaccid) tympanic membraneNormal hearing, unusual curve; it does not establish a diagnosis on its own.
Moderate
Cochlear hearing lossThe tympanogram is normal; the clue lies in the gap between the reflex and hearing thresholds.
Moderate
Severe sensorineural lossSevere loss in one ear; in which pathways does the reflex disappear?
Moderate
Patulous Eustachian tubeA patient who hears their own voice in their ear; does admittance change with breathing?
Moderate
Eustachian tube dysfunctionComplaint of pressure in the ear; does the tube open with Valsalva and Toynbee?
Hard
Retrocochlear lesionUnilateral complaint; the reflex pattern and the reflex decay test are interpreted together.
Hard
Facial nerve involvementA patient presenting with facial paralysis; the reflex pattern shows the site of the lesion.
Hard
Brainstem lesionHearing thresholds are normal; some reflex pathways are unexpectedly absent.
Hard
Borderline curvesCurves that fall between normal and abnormal; you justify your decision against the criteria.

There is also a Blind case is available as an option: the case is chosen at random, the diagnosis is hidden and the middle ear cross-section does not show the findings. The blind case runs only in Free mode; you learn the diagnosis when you submit your assessment. Infant cases (1000 Hz probe tone) will be added in the next version.

Preparation and the 3D scene

The quality of the measurement is decided before the probe enters the ear. The simulator lets you skip these steps, but it shows in the result.

Probe in the ear: the seal check, with the live middle ear cross-section on the right.

Prepare the patient

  • ENT noteThe patient hands you the note. It gives the history, the otoscopy finding for both ears and the reason for referral; you choose the tests.
  • Instructions“You will feel a brief sound and some pressure in your ear. Please do not talk or swallow during the test.” If no instructions are given, the patient swallows more often and moves their head.
  • Probe tipTry one of the six sizes in the box. A tip that is too small lets pressure escape, one that is too large does not fit into the canal; the canal diameter may differ between the two ears.
  • Seal checkThe device tries to pressurise the canal to +200 daPa; if the pressure does not hold, there is a leak and the measurement does not start.
  • ArtefaktlarSwallowing and head movement cause deflections in the curve and in the reflex trace. Recognising the artefact and repeating the measurement is your job.

Live middle ear cross-section

In the window on the right of the screen, an enlarged cross-section of the middle ear moves in step with the measurement.

  • Pressure and eardrumAs the canal pressure changes, the eardrum flexes inwards or outwards; when the pressures are equal, it moves most freely.
  • Stapedius muscleWith the reflex stimulus, the stapedius muscle contracts, the ossicular chain stiffens and admittance falls. In the contra pathway, the stimulus is delivered to the opposite ear through headphones.
  • Pathology viewsFluid, perforation, tubes, wax, ossicular chain problems and a patulous Eustachian tube are visible in the cross-section; they are hidden in the blind case.
  • WindowYou can drag the cross-section, zoom in and out, and turn the labels on and off.

Tests

The four tabs on the device panel cover the core immittance measurements used in the clinic.

Live results on the desk computer and the thermal printer output.
TestIn the simulator
TympanometryTracking admittance as the pressure changesProbe tone 226, 678 or 1000 Hz; sweep speed 50, 200 or 600 daPa/s. On screen: ear canal volume, Ytm, peak pressure, width and gradient.
Acoustic reflexContraction of the stapedius muscle in response to loud soundIpsi and contra pathways; 500, 1000, 2000, 4000 Hz and broadband noise. Manual search in 5 dB steps or automatic search; the threshold is confirmed by a growing response 5 dB above it.
Reflex decay testWhether the reflex is sustained for 10 seconds10 dB above threshold, at 500 or 1000 Hz. Positive if the response falls below 50% of its initial amplitude.
Eustachian tube testsWhether the tube can open and equalise pressureWith an intact eardrum, Valsalva and Toynbee (three tympanograms), patulous Eustachian tube recording (30 s of breathing), inflation-deflation with a perforated eardrum.

Reflex results are collected in a separate window, together with a table, the Metz difference and a reflex pattern diagram showing the four pathways.

Criteria used by the simulator

For adults, the simulator assesses your answers against the criteria below. Where the literature gives different values, these are noted alongside.

CriterionValue (adult, 226 Hz)
Type ANormal middle earPeak pressure between +50 and −100 daPa, static compliance 0.3-1.6 cm³
Type As and AdLow and high complianceAs: below 0.3 cm³ · Ad: above 1.6 cm³ (peak pressure within the normal range)
Type BNo clear peakInterpreted together with the ear canal volume: normal, large or small volume
Type CNegative peak pressurePeak pressure more negative than −100 daPa. If the peak is low, it may also be described as "low compliance in the negative pressure range".
Ear canal volumeAir in the canal in front of the probe0.6-2.2 cm³. A difference of more than 1.0 cm³ between the ears may be consistent with a perforation.
Width and gradientShape of the curveWidth 48-134 daPa; a gradient below 0.2 is considered abnormal.
Reflex searchStarting level and stepFrom 70 dB HL (60 dB for broadband noise) in 5 dB steps, upper limit 105 dB HL (BSA). Some clinical protocols start at 85 dB HL.
Reflex decay testThreshold + 10 dB, 10 sPositive if the response falls below 50% of its initial amplitude (retrocochlear finding).
Metz testReflex threshold − hearing thresholdA difference of 60 dB or less is consistent with cochlear loss.
Valsalva and ToynbeeShift in peak pressureA shift of at least +15 daPa with Valsalva and at least −15 daPa with Toynbee shows that the tube can open.

Modes, score and achievements

You can practise the same case with different levels of support. Your score looks not only at your interpretation but also at how you carried out the measurement.

Three practice modes

  • LearningYou follow the clinical sequence step by step: ENT note, instructions, probe, tympanometry in both ears, reflexes, decay and Eustachian tube tests if needed, assessment. Every step has a “Why?” explanation; the next test unlocks when the previous one is complete.
  • GuidedYou carry out the tests in any order you like; hints on norms, the search rule and additional tests suited to the history appear as they become relevant.
  • FieldThere are no hints; you only see warnings for clear errors. The blind case runs in this mode.

How is the score calculated?

  1. 1
    Interpretation (70%)Tympanogram type, likely diagnosis, justification for borderline curves, the four reflex pathways and the reflex pattern.
  2. 2
    Procedure (30%)Giving the instructions before measuring, finding the right tip on the first try, not recording a threshold without confirming it, repeating a recording with artefacts and not presenting unnecessarily loud stimuli.
  3. 3
    Stars and experienceYour total score is converted into 1-3 stars; with experience points you level up and earn achievements such as First Case, Flawless Interpretation, Reflex Master and Borderline Spotter.

Your progress is stored only in your own browser; no data is sent to a server.

Frequently asked questions

Curves obtained with a 226 Hz probe tone are classified by peak pressure and static compliance. Type A shows normal peak pressure and compliance, As low, Ad high compliance. Type B: no clear peak; Type C: peak in the negative pressure range.

The type alone does not establish a diagnosis: the same flat curve can be seen with fluid, a perforation or wax. The ear canal volume, the otoscopy finding and the reflexes make the distinction.

With a flat curve, the volume measurement shows where the problem lies. If the volume is normal, fluid in the middle ear is considered; if it is clearly large, an opening in the eardrum (a perforation or a patent ventilation tube); if it is very small, the probe resting against the canal wall, or wax.

The first deflection that meets the criterion is a threshold candidate. A response must be obtained on the same pathway with a stimulus 5 dB higher, and the response must grow; only then is the candidate level accepted as the threshold. This way, a single deflection caused by swallowing or movement is not mistaken for a reflex.

The simulator does not let you record an unconfirmed threshold; the automatic search applies the same rule.

Pathways are named after the stimulated ear. In the "right contra" reflex, the stimulus is delivered to the right ear and the response is measured with the probe in the left ear. This rule matters when you read the reflex pattern: if the reflex is absent in both pathways in which the same ear is stimulated, the problem lies in that ear's auditory pathway; if it is absent in both pathways with the probe in the same ear, the problem lies in the middle ear or the facial nerve on that side.

The stimulus is presented 10 dB above the reflex threshold, at 500 or 1000 Hz, for 10 seconds. If the response stays above 50% of its initial amplitude throughout the 10 seconds, the test is negative. If it falls below 50%, the test is positive and suggests a retrocochlear lesion.

In infants younger than 6 months, a 226 Hz tympanogram can look normal even when there is fluid in the middle ear, because the canal wall is so compliant; 1000 Hz is recommended at this age. 678 Hz is used in high-frequency tympanometry to examine notched curves. In adults, the 1000 Hz curve usually appears notched.

If the eardrum is intact, Valsalva or Toynbee is performed: a tympanogram is recorded first, repeated after the manoeuvre, and a third one is recorded after swallowing. If a patulous Eustachian tube is suspected, a recording is made while the patient breathes in and out. If the eardrum is perforated or a tube is in place, the inflation-deflation test is used.

No. The simulator runs entirely in your browser; no measurements are sent to a server. Your level, best scores and achievements are stored only in your own browser's local storage.

The 3D room, the middle ear cross-section and the device panel must be visible at the same time. At phone width this layout becomes unusable, so small screens have been deliberately blocked. It works on a tablet held in landscape.

No. The person being tested here is a virtual patient, and you are the clinician. If you have concerns about your hearing or your ears, contact an audiology clinic.

Kaynaklar

The simulator's criteria, case models and interpretation key are based on the sources below.

If you are ready, let's go into the room

If you spot an error, if a criterion does not work correctly or if there is a case you would like us to add, write to us: info@isitmeatolyesi.com. The simulator is an open-ended educational project; it grows with your feedback.

© 2026 Ahmet Alperen Akbulut, Auditory Scene. All rights reserved. It may not be copied, reproduced or distributed without permission.This covers the simulator's software, 3D scenes, case data, images and report templates. For permission requests: info@isitmeatolyesi.com