Tympanometry

The Tympanometry element simulates a clinical tympanogram — the trace of middle-ear admittance (compliance) as ear-canal pressure is swept from positive to negative (the clinical default; the reverse is available — see Testing). From that curve a clinician reads the peak admittance, the peak pressure, the tympanometric width (gradient), and the ear-canal volume (ECV), then classifies the result into a Jerger type (A, As, Ad, B, C, or a small/large ear-canal-volume pattern).

In a submission, the learner presses Run to sweep each ear, watches the curve draw in, reads off the measurements shown beneath the chart, and records a tympanogram type for the right and left ears. Theta then compares the learner's classification against the one you designed.

Each element holds both ears (Right and Left), so a single tympanometry element gives the learner a complete bilateral result to interpret.

Design

Probe tone

At the top of the Design tab, pick the Probe tone the case calls for — one for the whole element, since both ears are tested at the same tone. It's 226 Hz by default (adults and children); choose 1000 Hz for an infant under about six months. It's the correct answer the learner's own choice is scored against. A case built before the probe tone existed is treated as 226 Hz.

The ears

You design each ear independently. The two charts sit at the top of the editor and update live as you change the fields below them, so you can see exactly what the learner will see.

Choosing a type

The quickest way to build an ear is to pick a Tympanogram type. Selecting a type regenerates realistic peak, pressure, gradient and volume values that match that classification:

The three flat types (B, small ECV, large ECV) have no peak, so the chart shows no peak marker and the peak readouts display NA. They differ only in ear-canal volume, which is what distinguishes, for example, a flat trace with a perforation or patent grommet (large ECV) from one with an occluded probe or impacted canal (small ECV).

The values you set per ear

After choosing a type you can fine-tune any value directly. Each field feeds the curve drawing and the measurement readouts:

If you hand-tune the numbers far enough that the curve no longer reads as the type you chose — dropping the peak admittance below the normal floor while the type still says A, say — the editor warns you under that ear. Leaving it unresolved means learners get marked wrong for reading the trace correctly, so either move the value back or change the type to match.

Artifact (patient movement)

You can add a realistic artifact to either ear to simulate what patient movement, talking or swallowing does to a real trace. Pick a level from the Artifact dropdown beside the type (None leaves the curve clean):

• Low — peak still clear. A few narrow spikes; the peak is plainly visible.
• Medium — messy but readable. Dense spikes, a wandering baseline and a couple of bursts away from the peak. Ugly, but the real peak is still the tallest thing on the trace.
• High — no discernible peak. The real peak is knocked down and bigger bursts elsewhere out-top it. The machine's peak readouts follow the noise too, so nothing gives the true peak away — the only fix is a clean re-run.

Each run of a noisy ear draws a different pattern, as a real re-run would. How the artifact clears — on its own when re-tested, or only once the learner reinstructs the patient — is set on the Settings tab.

Template vs. fixed

Like every Theta element, tympanometry can be fixed or a template.

• Fixed — every learner sees the exact curve and values you entered.
• Template — at submission time Theta generates a fresh tympanogram of the same type within normative ranges, so each learner gets slightly different numbers but the same correct classification. This is ideal for assessment, since the answer can't simply be shared.

When the element is a template, each ear shows a Shuffle button beside Run. Press it to preview a random tympanogram of that type (not saved) so you can confirm the generated curves still read as the intended classification; Reset clears the preview.

Batches — tympanogram types

Add a batch… → Tympanogram types drops a set of patients into the lesson for the learner to name every tympanogram, dealt fresh every attempt. You choose how many patients, and the mix: tick the types to include and give each a share (the dialog shows what each will get — "→ 2–3" of twenty ears). Spread evenly shares them out equally.

• Both ears, each its own roll. The mix is dealt over ears, not patients: ten patients are twenty tympanograms, and 30% Type B is six Type B ears. A patient's two ears are paired at random — never the same tympanogram twice.
• Every tympanogram's values are drawn fresh for its type, under this lesson's normative range.
• Only the type is graded — the probe tone isn't asked.
• The results screen and PDF open with a batch summary: overall accuracy over ears, the type missed most often, and one line per patient with both ears.

A batch lesson holds only its batch and Information elements — see Audiometry → Batches for how batches work.

Settings

The Settings tab holds three things: the display scale (the window the curve is drawn in), how an artifact clears, and the normative range (what counts as normal).

Display scale

A chart-wide setting controlling the axes the curve is drawn against. This sets the window, not the values.

The display scale is shared across both ears so the two charts stay directly comparable. Axis gridlines are placed at round values automatically whatever scale you choose. These defaults can also be supplied by your organization's element preset.

Artifact

Only matters for an ear you designed with an artifact:

Your organization can set the default for new elements in its element presets.

Normative range

Below that you set one normative range for the element, used for both ears — the boundaries of "normal" that define every type:

These boundaries do real work in three places, so they're worth setting deliberately:

1. They are the shaded "normal" box learners can toggle on during a submission.
2. They constrain what a template generates — a template As is always placed below your admittance minimum, whatever you set it to.
3. When a learner applies an element preset to a Theta platform case, the expected type is re-derived against that preset's boundaries, so the same designed curve can legitimately grade as A under one set of norms and As under a stricter one.

An element saved before there was a single range kept one range per ear; it shows the right ear's values, and the first edit applies them to both. Reset to Defaults returns the range, the artifact setting and the display scale to the Theta values.

Testing

When a learner reaches a tympanometry element, the main area shows just the two tympanograms (side by side on desktop, stacked below that). Every control is in a console pinned along the bottom of the screen, laid out like the charts: the right ear's controls on the left, the probe tone in the middle, and the left ear's controls on the right. Each ear has its own Run button in its colour — red for right, blue for left — with its type dropdown beneath. On a phone the probe tone sits across the top of the console and the two ears side by side under it.

1. Choose the probe tone. In the middle of the console, the learner picks 226 Hz or 1000 Hz. When the probe tone is Scored, Run stays locked until they do — choosing the tone is part of the task. When it's Report-only, the picker is shown but Run isn't locked: a learner who runs without choosing runs at 226 Hz. When it's Off, the picker is hidden and every run is at 226 Hz, whatever tone the case was designed with. With sound on, the probe tone plays at the chosen pitch (226 or 1000 Hz) for a second on its own, then through the sweep, then a second after it ends — so it's clear the steady tone isn't what draws the curve.
2. Run the test. Pressing Run animates the pressure sweep and draws the curve in. When the sweep finishes, the measurement readouts appear beneath the chart: peak pressure, peak admittance, tympanometric width, and estimated ECV. Flat types show NA for the peak measurements. The learner can re-run a sweep as often as they like: each new trace draws over the previous one, which stays on the chart in faded grey (the chart keeps the last two). A small Clear tracings button beside each ear's Run wipes that ear's chart. On a fixed case every run lands exactly on the designed curve; on a template each run shifts the peak pressure 10–20 daPa (and the width a touch), the way repeat measurements do — never enough to change the type, and the peak admittance and ear-canal volume never move.
3. Read the curve. A peak marker labels the peak admittance, and a dashed half-peak line shows where the width is measured — the same cues a clinician uses to judge sharpness and centre pressure.
4. Classify. Under each ear's Run button is a Tympanogram type dropdown. The learner chooses the type (A, As, Ad, B, C, small/large ECV) that matches the trace. This selection is the answer that gets scored.

Under the probe tone, a Sweep direction toggle sets which way the pump sweeps. + → − (from the positive to the negative end of the scale) is the clinical default, and it is what your designed values describe, so the answer never depends on the direction. + ← − redraws the same ear the way an instrument records an ascending sweep, for learners who want to see the difference: the peak lands about 11 daPa more positive (sweep hysteresis), the peak reads about 10% taller and slightly narrower, the canal volume reads about 10% smaller, and the positive tail sits a little higher than the negative one. At 1000 Hz the starting (negative) tail collapses toward zero, as an infant canal does. Each trace draws in the direction it was swept: + → − from the right, + ← − from the left. None of these shifts is ever big enough to change the type: an effect that would (a Type As lifted into A, an A into Ad, a B tipped into small ECV, a C lifted into A) is scaled back until it doesn't. When you switch direction on a template case, the new run keeps the previous run's random variation, so the two overlaid traces show the sweep effect alone. Direction is never scored.

If the trace is disturbed by an artifact, a small Reinstruct button appears beside that ear's Run after its first run. Pressing it is the clinical fix — asking the patient to sit still, not talk or swallow — and the next run comes out clean. (Under Clears on re-test, simply running again also works.)

A settings (gear) menu in the corner lets learners overlay the normative range box as a study aid — a shaded region marking where a normal peak should fall — and turn the probe tone sound off or on (on by default; the choice is remembered on that browser).

The learner's selections save automatically as they work. Their probe-tone choice, each run (and whether it was disturbed), any reinstruction, and their type selections are logged, so an instructor replaying the attempt sees the same noisy or clean traces the learner saw.

Scoring

Tympanometry scores two things: the probe tone (one choice for the element) and the tympanogram type for each ear. Each is set to one of three states (see Scoring overview):

New elements score both by default. Scoring saved before the probe tone existed leaves it Off, so older lessons grade exactly as before. The type is scored for both ears by default. A Sync ears toggle (on by default) applies the same state to both ears at once; turn it off to score the ears independently — useful when only one ear carries the teaching point. Sync ears doesn't touch the probe tone, which is a single choice.

Because scoring compares the type, a template element still grades cleanly: the generated numbers differ per learner, but the correct classification is fixed, and that's what's checked.

Report

When a submission is reported, each ear's tympanogram is redrawn in the PDF on the same axes the learner saw — including a widened sweep or an adaptive y-axis — so the report shows the curve they interpreted, in the ear's colour, with:

• The clean designed curve — without any artifact, since the report (like the results screen) shows the answer key — and a peak marker labelled with the peak admittance.
• A dashed half-peak line for the tympanometric width.
• A measurements block listing peak pressure, peak admittance, tympanometric width, estimated ECV, and the type — with the peak measurements shown as NA for flat types.

Alongside the visual, the data table compares the expected probe tone against the learner's choice, and the designed type against the learner's selected type for each scored ear, and marks it correct or incorrect. Report-only fields appear in the table for context but are not counted.