Hearing Aids

Theta models amplification as three separate elements that can be used alone or chained together:

In the designer's element palette all three sit under the Amplification group. Like every Theta element, each follows the lifecycle Design → Settings → Testing → Scoring → Report.

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Hearing Aid Selection

Selection asks the learner two independent things, and scores them separately.

1. The laterality decision

Both ears are always presented to the learner, regardless of what the case recommends. For each ear they choose Fit this ear or No device.

On the Design tab you set the answer key the same way — per ear, Fit a device or No device. An ear marked "No device" is a correct answer in its own right: a learner who recognises the ear doesn't need aiding earns that point, exactly like a learner who correctly aids one that does.

This makes unilateral fittings — and cases where amplification isn't indicated at all — teachable without needing a separate element.

2. The device configuration

For each ear you recommend fitting, you build the device across six axes:

Some axes constrain others, and the designer enforces it as you build: a custom in-ear style (ITE, CIC) is its own mold, so it can't take a dome; retention follows the coupling (domes take a retention line or nothing, earmolds take a skeleton or canal lock). Switch to an ITE with a dome selected and the coupling flips to an earmold automatically.

Acceptable alternatives

Under each axis, Also accept lets you mark options that are also defensible. With Accept clinically-equivalent alternatives on in the Scoring tab (the default), any marked option scores correct — so a case where either a RIC or a BTE is reasonable doesn't punish the learner for choosing the one you didn't.

One device or two

When both ears are fitted, the designer shows a single Both ears column and mirrors every edit to both. Tick Configure ears independently for an asymmetric fitting and the ears split into side-by-side columns.

The candidacy helper

Suggest from a loss scenario picks a recommended device plus a sensible set of acceptable alternatives from one of five scenarios:

It's a transparent starting point, not a fitting formula — override anything afterwards. The rule is deliberately explainable so you can teach why it suggests what it does.

Device implications

As you build, the designer shows the max gain per region the device can deliver and a plain-language list of what the choice implies — the same constraints a downstream Fitting or REM element will enforce. This is where you check that the device you're recommending can actually do the job.

Settings

• Device axes asked — which of the six axes the learner is asked to choose. Disabled axes are hidden from them and can't be scored. Both ears are always presented, so the fit / no-fit decision is asked even with no axes enabled.
• Learner rationale — adds a free-text box asking the learner to justify their choice. It appears on the report and in the on-screen results, but is never scored; it's for you to read.
• Device catalog — see below.

Device catalog (branding)

Catalogs re-label the options the learner sees — Premium can display as "Audéo 90" — while the underlying values, and therefore all scoring, stay generic. Built-in catalogs ship for several manufacturers plus a Theta default.

The catalog normally comes from your organization's settings preset, so you edit it once and every case follows. The per-element override on the Settings tab exists only for the rare case that must show a different brand than the rest of your course.

Scoring

Two blocks, each using the standard Off / Scored / Report-only control:

• Fit decision (laterality) — per ear, independent of the device.
• Device configuration — per axis, applied to both ears.

The element's total is set by the design, not by what the learner does: every ear the case recommends fitting contributes its scored axes whether or not the learner chose to fit it. A learner who answers "No device" everywhere is graded out of the same total as one who engages, so the two are directly comparable.

An ear the case leaves unaided has no recommended device to compare against, so it contributes only its fit decision.

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Hearing Aid Fitting

Fitting hands the learner a device that is deliberately off target and a set of patient complaints, and asks them to adjust it.

The console

The console is a grid of input level × frequency: soft (50 dB SPL), average (65), and loud (80) inputs against the device's tunable frequencies — 3, 6, or 9 of them depending on the technology tier. Premium devices give more bands, and therefore finer control. Alongside it sits an MPO row.

Both the grid and the graph show output in dB SPL, not insertion gain. Louder speech produces louder output, so the Loud 80 curve sits on top, Avg 65 below it and Soft 50 at the bottom — while the gain being applied shrinks as the input rises, which reads as the curves converging. That convergence is the compression. (A gain axis inverts the stack, because soft input gets the most gain, and it can't show MPO at all — MPO is an output ceiling, and gain is not an output.)

The learner selects cells — by dragging, or by tapping a frequency, row, or region header — and one − / + moves the whole selection. Selecting a frequency or a region picks the three gain curves only; MPO is never swept up with them, because changing the patient's tolerance ceiling should always be a separate, deliberate act. The MPO row has its own header.

The prescriptive target is hidden from the learner. They find it by listening to the patient.

MPO is the patient's tolerance, not the receiver's limit

Two ceilings appear on the graph and they are different things:

The prescribed MPO is derived from the loss, like the gain target is. OSPL90 only caps it: choose an under-powered receiver for a patient with a high tolerance and the MPO simply cannot be programmed where it belongs — which is exactly the consequence a selection error should have. No output may exceed the MPO, so a learner who runs the gain into the ceiling has to raise the MPO first, if the receiver allows it.

Complaints

You author the starting point by choosing complaints rather than by nudging numbers:

Theta builds a starting fit that produces exactly the complaints you ticked. The patient's responses are deterministic: the same grid always yields the same complaints, and they disappear as the learner brings each region inside tolerance. The learner uses Ask the patient to hear the current complaints — you can cap how many times.

Because the complaints are stored as intent rather than as fixed numbers, they survive anything that moves the target: swapping the device, editing the linked audiogram, or a per-submission template roll.

Where the device and the loss come from

• Device — link a Hearing Aid Selection element and the fitting inherits its device. At design time that's the recommended device; at submission it's the device the learner actually selected, so a selection error carries through into the constraints they have to work within. Leave it unlinked to configure the device inline.
• Loss — link an audiogram and the per-frequency loss (and therefore the target) is sampled from it, and the element inherits the audiogram's template status. Unlinked, you enter the loss by region manually.

Settings

• Tolerance — the ± dB window counted as on-target. It also drives complaint generation, so a tighter tolerance makes the case harder in both senses.
• Step size — dB per tap in the console.
• Max asks — cap on "Ask the patient" uses (unlimited by default).

Scoring

Choose a mode:

Points are awarded per region, not per frequency. The scoring grid is low / mid / high, but a device's tunable bands are not — a premium aid programs three frequencies inside a region where a basic one programs one. A ticked region is one point and needs every band inside it on target, so the same scoring setup carries the same weight whichever device the case uses. The report still lists each frequency individually.

When the device is inherited from a Selection element, strict vs flex decides how a wrong device is treated:

• Flex (default) — grade against the target clamped to what the device the learner chose can actually reach. A good fit on the "wrong" device still earns credit.
• Strict — grade against the intended target. A device that physically can't reach it loses those bands.

Flex is the default because the selection error is already scored in the Selection element; strict scores it twice, which is sometimes what you want and rarely what you expect.

Either way the patient always reacts to the aid that is actually in their ear: complaints are judged against what the chosen device can deliver, so a learner is never left with a complaint they have no physical way to clear.

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Real Ear Measurement

REM verifies the fit in the actual ear, on a speech map: measured output against prescriptive target, for soft / average / loud inputs, plus an MPO run.

The probe tube

Placement is a real task with a real acceptable window (in mm). Too shallow gives degraded high-frequency measures; too deep is uncomfortable for the patient.

The probe placement setting decides whose problem that is:

The last two are how you teach recognising a bad probe trace without making the learner produce one.

Prescriptive formula

The element carries a prescriptive formula, and you can score whether the learner picked the one you intended.

The chain from Fitting

Link a Hearing Aid Fitting element and REM seeds its measured curves from the learner's saved fitting — so what they programmed is what the probe measures. Unlinked, the element carries its own measured curves and stands alone.

Each frequency also carries the patient's UCL: exceed it during the MPO run and the patient flinches. MPO bands are scored both on matching target and on not exceeding UCL.

Scoring

Standard Off / Scored / Report-only control over:

• Probe placement (inert unless the probe is the learner's task)
• Prescriptive formula choice
• Speech-map gain cells — input level × region
• MPO bands

REM uses the same strict / flex rule as Fitting, for the same reason.

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Building the chain

Add the elements in clinical order and the designer wires them up for you:

1. Audiogram — the loss everything else derives from.
2. Hearing Aid Selection — auto-configured from the audiogram if one is present.
3. Hearing Aid Fitting — automatically links to the first Selection element (for the device) and the first audiogram (for the loss and template status).
4. Real Ear Measurement — links to the Fitting for its measured curves.

Every link is overridable in the element's own designer, and each element works standalone if you'd rather teach one step in isolation. Deleting an upstream element doesn't break the ones below it — they keep working from the device snapshot they already hold.