Changing tempo produces a different audio file, so its AI detection result needs a fresh check. It is not a demonstrated fingerprint-removal method by itself. A useful experiment holds pitch and export settings fixed and records the duration change as well as the detector result.

Time stretching and playback speed are different tests

Audacity’s Change Tempo changes duration without changing pitch. A speed change can alter both. Specify which operation you used; otherwise a result cannot be attributed to timing alone.

Changing a tempo tag without modifying audio is yet another operation. Label it separately. The tempo experiment below concerns time stretching of the actual waveform.

Set up a tempo-only comparison

This is an experiment design, not a completed benchmark.

  1. Archive the source and make an unchanged export control.
  2. Choose the tempo factors before testing and apply each directly to the source.
  3. Keep pitch, gain, EQ, channels, sample rate and codec settings fixed.
  4. Record source and output duration, factor, software version and stretch algorithm.
  5. Submit the complete source, control and outputs to the same detector.
  6. Retain every report, including errors and unsuccessful outcomes.

For a tempo factor r, expected duration is approximately source duration divided by r, before rounding or padding. Check the exported duration rather than relying only on the editor’s BPM display.

Account for the detector’s listening window

A fixed-duration excerpt may cover different musical events after stretching. For example, an earlier chorus may move outside that excerpt. Test complete files where supported, record any truncation, and distinguish equal-length excerpts from excerpts aligned to the same musical passage.

If the detector’s sampling policy is unknown, record that uncertainty. A score difference does not reveal whether the detector reacted to the transformation, the changed material sampled, or both.

Check percussion and transitions

Audacity notes that more extreme time stretching can introduce audible distortion. Inspect attacks, sustained notes and reverberation, then check any album transitions that depend on exact timing. A duration change can matter even when a standalone track remains acceptable.

Keep listening adjustments separate from the submitted files. See the quality checklist for level and frequency observations.

What can be concluded now?

This page provides no measured SH Labs improvement from tempo changes: paired files and reports for this isolated experiment are not published here. A combined Cleaner result is not a tempo-only result. Compare this protocol with the pitch experiment before choosing a variable to investigate.

For a complete processing workflow, Cleaner returns the selected export with its external detection result.

Prepared with AI assistance. Sources below.

Sources and documentation