Section 213 of 440
Complete canonical tutorial. This reader section contains the same teaching body as PWR-030 · Quiet locomotion. Open the Power dossier.
PWR-030 · Mobility, Balance & Locomotion
Describe footstep sound in a declared recording without changing gait
This pack supplies fictional measurements from recordings that already exist. The learner reports peak sound in each recording setup, checks which configurations can be compared, and keeps sound separate from force, tissue safety, stealth, and gait quality.
Tutorial curriculum · current public edition · Revision 7T · Full Tutorial Edition
Revision 7T · Full Tutorial Edition · complete governed practice tutorial
Describe footstep sound in a declared recording without changing gait
This pack supplies fictional measurements from recordings that already exist. The learner reports peak sound in each recording setup, checks which configurations can be compared, and keeps sound separate from force, tissue safety, stealth, and gait quality.
Authority and safety
- Do not make a new walking take, change speed, change foot strike, remove an aid, or try to walk quietly for this exercise.
- Use the fictional data below or an ordinary recording that already exists and was made safely.
- Peak dBA is a sound measurement in a declared setup; it is not ground-reaction force, loading rate, tissue safety, or a judgement about an aid or prosthesis.
Exact materials
- The three fictional recording rows below
- Paper or spreadsheet
- A calculator, optional
- No walking task and no new recording
Set up in this order
- For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode, and the five peak readings.
- Sort the five readings and select the middle value as the median peak dBA.
- Calculate the range as maximum minus minimum.
- Compare clips only after checking which configuration fields match.
- Describe the observed sound difference without inferring force or safety.
- Finish with a bounded conclusion and a list of non-claims.
Supplied fixture
| Clip | Surface | Footwear and aid | Speed m per s | Microphone distance m | Meter mode | Five peak readings dba |
|---|---|---|---|---|---|---|
| A | Vinyl | Walking shoes; no aid | 1.2 | 1 | Same fictional peak-dBA meter | 62; 64; 63; 61; 65 |
| B | Carpet | Walking shoes; no aid | 1.2 | 1 | Same fictional peak-dBA meter | 55; 56; 54; 55; 55 |
| C | Vinyl | Boots; cane present | 1.4 | 0.5 | Same fictional peak-dBA meter | 68; 69; 67; 70; 68 |
Check your work only after you finish
Lock every response first. The checking page is separate so the answers are not exposed inside this exercise.
Scoring rule
Award 1 point per correct median and range, 2 points for the A/B configuration comparison, 2 points for rejecting A/C as like-for-like, and 2 points for the sound-not-force boundary: 12 points total.
Worked example
- Sort A: 61, 62, 63, 64, 65; the middle value is 63 dBA.
- Calculate A's range: 65 - 61 = 4 dB.
- Sort B: 54, 55, 55, 55, 56; the middle value is 55 dBA.
- Calculate B's range: 56 - 54 = 2 dB.
- Check configuration: footwear, aid, speed, microphone distance, and meter match; surface differs.
- Calculate the descriptive median difference: 63 - 55 = 8 dB.
Correct result: In these fictional recordings, Clip B on carpet has a median peak 8 dB below Clip A on vinyl. This observation is about recorded sound only and does not establish lower force, safer loading, better gait, or stealth.
Right and wrong
| Moment | Right / safer | Wrong / riskier | Why |
|---|---|---|---|
| Describing A versus B | B's median recorded peak is 8 dB lower in the declared setup. | Carpet makes this person land with less force. | There is no force measurement or causal replication. |
| Using Clip C | Report C separately because footwear, aid, speed, and microphone distance differ. | C proves the person's gait became louder. | Several recording and task fields changed. |
| Handling an aid sound | Record the cane as part of the sound configuration without ranking it. | Remove the cane so the recording is cleaner. | Removing support changes the task and may be unsafe. |
| Summarising decibels | Use the declared median peak statistic for this exercise. | Average decibels as if they were ordinary linear energy values and omit the meter mode. | Decibels are logarithmic and the measurement rule must remain explicit. |
Common mistakes and fixes
| Mistake | Fix |
|---|---|
| Changing walking technique to produce a quieter comparison. | Use only the supplied fictional data or an existing clip; do not create another take. |
| Comparing readings taken at different microphone distances as if only gait changed. | Mark the configurations different and report them separately. |
| Calling sound a proxy for force or injury risk. | Write force, loading, and tissue safety in the non-claims field. |
| Treating an aid or prosthesis sound as an error. | Record it neutrally as part of the capability configuration and preserve the aid. |
Evidence boundary
What the tutorial may—and may not—claim.
Supportable claim
People can acutely reduce footstep sound and impact in a laboratory, often by changing speed or foot strike; durable skill and injury benefit are unproven.
Measurement boundary
Decibels establish sound in the measurement setup; force plates establish loading. Neither alone establishes tissue safety or stealth.
Walk in supernatural silence
MetricFootstep decibels, loading rate and speed on a declared surface
BoundaryQuiet sound cannot prove invisibility, safety or universal technique.
Negative and limiting findings
- Peak sound was not directly associated with peak ground-reaction force or loading rate in the running experiment.
Prohibited wording
- Move like a ghost
- Silent walking prevents injury
- Sound reveals force exactly
- Forefoot striking is universally safer
Direct source register
Evidence that supports—and limits—the route.
Woojin Yoon; Yujin Kwon; Jaehyun Yoon; Seobin Choi; Gwanseob Shin · 2025 · PRIMARY_RESEARCH
Supports only the bounded empirical proposition in the declared configurations. Constrains generalisation, transfer, certainty or efficacy; it is not optional context.
Xuan Phan; Tiffany L Grisbrook; Kevin Wernli; Sarah M Stearne; Paul Davey; Leo Ng · 2017 · PRIMARY_RESEARCH
Supports only the bounded empirical proposition in the declared configurations. Constrains generalisation, transfer, certainty or efficacy; it is not optional context.
Tutorial delivery controls
Learn, adapt, troubleshoot and resume
Progress is saved only in this browser on this device.
Step-by-step learner mode
Each activity includes its success check, a nearby accessible alternative and an “I’m stuck” correction path. Alternatives preserve the target where possible; when they change the task, Titan labels them as related rather than equivalent.
For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode,…
For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode, and the five peak readings.
“For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode, and the five peak readings” creates the auditable value, condition or statement needed for the tutorial’s later comparison and conclusion.
A legible entry directly completes “For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode, and the five peak readings” and records the requested condition, decision or boundary without adding a new claim.
I’m stuck on this step
Reset: Re-read this authored instruction — “For every clip, copy surface, footwear, aid, speed, microphone distance, meter mode, and the five peak readings.” — and its success check, then attempt only this step.
Possible snag: Changing walking technique to produce a quieter comparison.
Correction: Use only the supplied fictional data or an existing clip; do not create another take.
Possible snag: Comparing readings taken at different microphone distances as if only gait changed.
Correction: Mark the configurations different and report them separately.
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Sort the five readings and select the middle value as the median…
Sort the five readings and select the middle value as the median peak dBA.
“Sort the five readings and select the middle value as the median peak dBA” fixes the exact Quiet locomotion configuration or decision before later observations are compared.
The learner can verify “Sort the five readings and select the middle value as the median peak dBA” from the declared materials, position or recorded choice before continuing.
I’m stuck on this step
Reset: Re-read this authored instruction — “Sort the five readings and select the middle value as the median peak dBA.” — and its success check, then attempt only this step.
Possible snag: The result from “Sort the five readings and select the middle value as the median peak dBA.” does not yet meet this declared check: The learner can verify “Sort the five readings and select the middle value as the median peak dBA” from the declared materials, position or recorded choice before continuing.
Correction: Return to the start of “Sort the five readings and select the middle value as the median…”, reduce complexity or pace, and repeat only the part needed to satisfy: “The learner can verify “Sort the five readings and select the middle value as the median peak dBA” from the declared materials, position or recorded choice before continuing.”
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Calculate the range as maximum minus minimum
Calculate the range as maximum minus minimum.
“Calculate the range as maximum minus minimum” creates the auditable value, condition or statement needed for the tutorial’s later comparison and conclusion.
The work shows the value requested by “Calculate the range as maximum minus minimum”, retains the supplied units or signs and leaves any unsupported value unknown.
I’m stuck on this step
Reset: Re-read this authored instruction — “Calculate the range as maximum minus minimum.” — and its success check, then attempt only this step.
Possible snag: The result from “Calculate the range as maximum minus minimum.” does not yet meet this declared check: The work shows the value requested by “Calculate the range as maximum minus minimum”, retains the supplied units or signs and leaves any unsupported value unknown.
Correction: Return to the start of “Calculate the range as maximum minus minimum”, reduce complexity or pace, and repeat only the part needed to satisfy: “The work shows the value requested by “Calculate the range as maximum minus minimum”, retains the supplied units or signs and leaves any unsupported value unknown.”
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Compare clips only after checking which configuration fields match
Compare clips only after checking which configuration fields match.
“Compare clips only after checking which configuration fields match” isolates the named evidence distinction so the learner can interpret Quiet locomotion without extending the claim.
The output directly answers “Compare clips only after checking which configuration fields match”, names the relevant distinction and stays within the supplied record.
I’m stuck on this step
Reset: Re-read this authored instruction — “Compare clips only after checking which configuration fields match.” — and its success check, then attempt only this step.
Possible snag: Treating an aid or prosthesis sound as an error.
Correction: Record it neutrally as part of the capability configuration and preserve the aid.
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Describe the observed sound difference without inferring force or safety
Describe the observed sound difference without inferring force or safety.
Keep this exact Quiet locomotion action explicit and reviewable: “Describe the observed sound difference without inferring force or safety.”
Evidence of completion shows the learner followed this exact instruction without adding an unstated step: “Describe the observed sound difference without inferring force or safety.”
I’m stuck on this step
Reset: Re-read this authored instruction — “Describe the observed sound difference without inferring force or safety.” — and its success check, then attempt only this step.
Possible snag: Calling sound a proxy for force or injury risk.
Correction: Write force, loading, and tissue safety in the non-claims field.
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Finish with a bounded conclusion and a list of non-claims
Finish with a bounded conclusion and a list of non-claims.
“Finish with a bounded conclusion and a list of non-claims” establishes the exact Quiet locomotion question or boundary that every later comparison must preserve.
Evidence of completion shows the learner followed this exact instruction without adding an unstated step: “Finish with a bounded conclusion and a list of non-claims.”
I’m stuck on this step
Reset: Re-read this authored instruction — “Finish with a bounded conclusion and a list of non-claims.” — and its success check, then attempt only this step.
Possible snag: The result from “Finish with a bounded conclusion and a list of non-claims.” does not yet meet this declared check: Evidence of completion shows the learner followed this exact instruction without adding an unstated step: “Finish with a bounded conclusion and a list of non-claims.”
Correction: Return to the start of “Finish with a bounded conclusion and a list of non-claims”, reduce complexity or pace, and repeat only the part needed to satisfy: “Evidence of completion shows the learner followed this exact instruction without adding an unstated step: “Finish with a bounded conclusion and a list of non-claims.””
Stop / get help: A governed exercise is available only in the declared configuration, dose and stopping rules. Stop if the declared configuration cannot be maintained, uncertainty becomes material, adverse effects appear, or qualified authority is required.
Correct versus incorrect execution
These accessible process diagrams are built from the tutorial’s own right/wrong teaching. They are not anatomical illustrations and do not add technique beyond the canonical tutorial.
B's median recorded peak is 8 dB lower in the declared setup.
Carpet makes this person land with less force.
Report C separately because footwear, aid, speed, and microphone distance differ.
C proves the person's gait became louder.
Record the cane as part of the sound configuration without ranking it.
Remove the cane so the recording is cleaner.
Use the declared median peak statistic for this exercise.
Average decibels as if they were ordinary linear energy values and omit the meter mode.
Method-structure checklist
10 of 10 structural checks present
- Ordered, Power-specific instructions — present
- Every activity has a success check — present
- Materials or supplied records are declared — present
- Measurement or assessment rule is present — present
- Tutorial-specific troubleshooting is present — present
- Stopping or escalation boundary is present — present
- Every activity has an adjacent alternative — present
- Correct-versus-incorrect comparison is present — present
- Evidence context is bound to the Power record — present
- Planning metadata is present — present
The method-readiness band and presence checklist assess tutorial presentation and are separate from evidence quality for the underlying Power. They are automated editorial aids, not human approval.
Manual editorial sign-off: Pending. This tutorial must not display a human-approved state until an identified editor signs the exact content hash.