Domain: Humanities and Social Sciences — Linguistics
Target concept: An experimental comparison of the acoustic waveform characteristics of plosives, fricatives, and nasals

Video generation prompt: A microphone is connected to a computer. The speaker produces three English consonant sounds in sequence, each spoken into the microphone: a plosive (/t/), a fricative (/θ/), and a nasal (/n/). Audio software displays the waveform corresponding to each sound in sequence.

Evaluation guide:
(i) Target concept: Real-time acoustic waveform differentiation among plosive, fricative, and nasal consonants.
Minimum mechanism: A functioning microphone-coupled audio capture system must convert vocal tract airflow events into time-domain voltage signals; plosive release creates impulsive energy, fricative turbulence creates stochastic broadband energy, nasal resonance creates periodic energy with formant structure, all resolvable as distinct time-domain morphologies on a standard audio waveform display.
(ii)Storyline: [0–2s] Microphone connected to computer; audio software interface visible and idle (flat line). [2–4s] Speaker articulates the isolated /t/ sound → waveform segment 1 appears: sharp onset + rapid decay to silence. [4–6s] Speaker articulates the isolated /θ/ sound → waveform segment 2 appears immediately after segment 1 ends: continuous, jagged, medium-amplitude noise. [6–8s] Speaker articulates the isolated /n/ sound → waveform segment 3 appears immediately after segment 2 ends: evenly spaced, sinusoidal-like peaks with steady amplitude. [8–10s] All three segments remain visible side-by-side in left-to-right order on screen; speaker is still, microphone unmoved, screen stable. Perspective: fixed frontal medium shot capturing speaker's mouth, microphone, and computer screen simultaneously; all critical elements fully in frame and unobstructed.

Manual:
Experimental Procedure
1. Connect microphone to computer via cable.
2. Open audio software showing real-time waveform display.
3. Speaker produces three sounds in order, each as an isolated consonant with no attached vowel: /t/, /θ/, /n/, each spoken clearly into microphone.
Observation of Experimental Phenomena
Three distinct waveform segments appear sequentially on screen: /t/ shows sharp onset + silence; /θ/ shows continuous noise; /n/ shows periodic peaks.
Summary of Experimental Principles
Plosives (/t/) generate transient bursts; fricatives (/θ/) produce sustained turbulent noise; nasals (/n/) yield quasi-periodic resonance due to velopharyngeal coupling and oral/nasal cavity coupling.

Prompt Grounding rubric:
level_1: No microphone is shown, no computer or audio-software display is shown, no speaker is present, no sounds are produced, and no waveform appears on screen: none of the requested setup elements are shown.
level_2: The microphone and computer are both visible but not connected to each other, or the speaker never audibly produces a sound while facing the microphone; in either case no waveform ever appears on the screen.
level_3: The microphone is visibly connected to the computer, the speaker produces three consonant sounds one after another into the microphone, and the screen shows some waveform activity, but the three waveform segments are not clearly matched one-to-one with the /t/, /θ/, /n/ sounds in that order (e.g., segments overlap, merge, or appear out of order).
level_4: The microphone is connected to the computer, the speaker produces exactly three sounds in order (/t/, then /θ/, then /n/), each directed into the microphone, and the screen displays three separate waveform segments in left-to-right order, each appearing only after its corresponding sound is spoken, with no segment skipped or duplicated.
level_5: The microphone is connected to the computer by a visible cable; the speaker, facing the camera with both mouth and microphone in view, produces only the three consonant sounds /t/, /θ/, /n/ in that order with no extra sounds; the screen shows one audio-software window with three non-overlapping waveform segments laid out left-to-right in that same order, each appearing right after its sound is spoken and remaining visible once the next segment starts.

Scientific and Causal Correctness rubric:
level_1: The three waveform segments show no relationship to plosive, fricative, or nasal acoustics at all: for example all three look identical, or the /t/ segment shows sustained noise, the /θ/ segment shows silence, and the /n/ segment shows a single sharp spike, with none matching its sound's known acoustic pattern.
level_2: At least two of the three segments show a shape typical of the wrong consonant class: e.g., the /t/ segment shows prolonged noise instead of a brief burst, the /θ/ segment shows silence or a sharp spike instead of continuous noise, or the /n/ segment shows no repeating pattern, or the three segments appear out of the /t/ → /θ/ → /n/ order.
level_3: The three segments appear in the correct /t/ → /θ/ → /n/ order and each begins as its corresponding sound is spoken, but at least one segment is missing its class-defining shape: the /t/ segment lacks a brief sharp burst followed by near-silence, the /θ/ segment lacks continuous irregular noise across its span, or the /n/ segment lacks a repeating, evenly spaced peak pattern.
level_4: The three segments appear in the correct order and timing; the /t/ segment shows a brief sharp burst followed by a quiet tail with no further noise; the /θ/ segment shows continuous irregular medium-amplitude noise across its whole span with no long silence within it; the /n/ segment shows a repeating pattern of peaks at roughly even spacing; one of the three may be only faintly legible but none contradicts its class.
level_5: The /t/ segment shows one sharp burst that decays to a visibly quiet tail with no further activity; the /θ/ segment shows continuous, irregular (non-repeating), medium-amplitude noise across its entire span with no silent gaps and no repeating peak pattern; the /n/ segment shows a clearly repeating pattern of similarly sized peaks spaced at even intervals across its entire span with no silent gaps and no burst-like spikes; the three shapes are clearly distinguishable from one another at a glance.

Spatiotemporal Consistency rubric:
level_1: The microphone or the computer screen disappears and reappears, the speaker's position jumps between shots, the waveform display resets or flashes to blank, a waveform segment appears before its sound is spoken or vanishes while still being viewed, the background changes abruptly, or the scene's overall lighting suddenly and drastically shifts (e.g., bright to dark) with no visible cause.
level_2: One major break occurs: the microphone visibly disconnects partway through, the speaker turns away and back with no sound produced in between, the waveform display freezes and then jumps ahead, or the room lighting changes noticeably between one sound and the next.
level_3: The microphone stays connected, the speaker stays in frame facing forward, and the screen stays lit and steady throughout; each waveform segment builds up smoothly in place with no jump-cut or flash between segments; at most one brief, minor stutter in the speaker's mouth movement or a slight screen-refresh flicker is present.
level_4: The microphone stays connected and in the same position, the speaker's head position and distance from the microphone stay constant, the screen shows one continuous display with no flicker or resolution change, and each waveform segment grows into place gradually rather than popping in fully formed; framing, lighting, and background stay constant throughout.
level_5: The microphone cable, the speaker's position, and the screen framing all stay fixed for the whole clip; the speaker's mouth moves only while each of the three sounds is being produced and is still the rest of the time; each waveform segment appears with a smooth, gradual build-in immediately after its sound begins, with no noticeable pop-in delay or freeze; lighting and camera framing never change and there is no reframe, zoom, or pan.