Workflows 5 min read
Listening at 1.5–2× Speed Without Chipmunk Audio: How It Works
Naive speed-up resamples the waveform faster — pitch rises. Time-stretching (atempo family) overlaps and crossfades short windows to compress time while keeping pitch. Speech tolerates this remarkably well; music is touchier.
Settings by content
- Speech/podcasts/lectures: 1.25–1.75× stays natural; beyond 2× start losing consonants.
- Music: avoid stretching; prefer pitch-preserving at most 1.1× or accept the chipmunk effect.
- Mixed content (interviews with stingers): 1.4× is the pragmatic sweet spot.
Artifacts to listen for
Stretching artifacts show as slight smearing on sibilants ("s", "sh") and reverb tails sounding drier. They are far less noticeable at 1.5× than the pitch shift. Processing happens locally — an hour of audio takes seconds.