Core concepts

A handful of terms recur throughout the portal. This page defines them once; later chapters assume them.

Trial structure

Trial

The whole study: its identity, its arms, its phases, the questionnaires, the audio, and the participants. A trial moves through a lifecycle from Draft to Completed (see Participants and the trial lifecycle).

Arm (treatment)

A distinct condition a participant can be in. There are four kinds:

  • Active: the therapeutic sound under test.

  • Sham: a control sound, paired with the active arm it mirrors so blinding works.

  • Washout (nothing): a rest period with no listening at all.

  • Washout (unmodulated): a rest period where participants still listen, but to a plain, unmodulated sound.

Phase

A stage of the trial over time, for example Baseline, an Intervention period, a Washout, and the post-trial Debrief. A trial is a sequence of phases; each intervention/washout phase is filled by an arm.

Randomisation sequence

The ordering of arms a participant follows. In a parallel trial each participant is placed in one arm and stays there. In a crossover trial every participant passes through all the arms, in a randomised order, each order is a sequence.

Recruitment

Completion target

The number of participants you expect to complete a given arm. It is a soft goal, never a hard cap, an arm may overshoot it. Targets also set how likely a new participant is to be assigned to each arm. See Enrolment and randomisation.

Estimated completion rate

The fraction of enrolled participants you expect to finish (default 0.5). It turns your completion targets into a total recruitment ceiling.

Questionnaires

Assessment

A questionnaire in the reusable library, its questions, how they are scored, and when they are asked. The same generic system renders every questionnaire in the app.

Timing

When an assessment is asked, for example before treatment, at the start or end of a treatment period, every day, or at the end of the trial.

Audio

Sound type

The category of therapeutic sound (for example an amplitude-modulated tone).

Hearing profile

A preset describing a participant’s hearing (for example Mild, Moderate), used to pick the right sound file.

Modulation band

The frequency band a sound is modulated in (for example 2–4 kHz). An unmodulated sound has no band.

These three together identify each uploaded sound; see Audio pipeline in depth.