A spectral transformation that remaps a linear frequency axis (Hertz) onto a non-linear perceptual frequency scale. The transformation applies a monotonic function f(frequency) where the output scale approximates human auditory perception — the mel scale uses f(f) = 2595·log₁₀(1 + f/700), the bark scale uses critical-band boundaries, and the ERB scale uses equivalent rectangular bandwidths. The parameters are the target perceptual scale and the input spectrum; persistence is achieved through standard implementation in DSP libraries and audio processing toolkits. [formal: freq_warping | substrate: behavior | horizon: hours | explicit: yes | epoch: 0.01]
Accepted ontology entry
freq-warping
A spectral transformation that remaps a linear frequency axis (Hertz) onto a non-linear perceptual frequency scale. The transformation applies a monotonic function f(frequency) where the output scale approximates human auditory perception…
Definition
Why it is in scope
A human-made spectral transformation that remaps a linear frequency axis onto a non-linear perceptual scale (mel, bark, erb). Used to align frequency representations with human auditory perception, it is a core preprocessing step for features like mel-filterbank, mel-frequency cepstral coefficients, and bark-scale analysis.
Names and aliases
- freq-warpingen · CANONICAL
Relations from this entry
- cmsop0xz702e7jlssmzq3gk17DEPENDS_ON →
Freq-warping operates on spectra: it remaps the frequency axis of a spectral representation. Remove spectrum from the pipeline and freq-warping has no data to transform — it stops operating entirely. Real object-level removal test.
- cmsq4obya07m0jlssh92wv3v0DEPENDS_ON →
Freq-warping remaps frequencies on a spectral representation (e.g., linear to mel scale). Remove spectral-representation and freq-warping has no data to warp — the removal test passes. The operation is defined entirely in terms of transforming spectral bins.
Relations to this entry
- cmspxgu9f06vtjlssp8aaz07z← DEPENDS_ON
Mel-filterbank applies triangular filters on a perceptually-warped frequency axis. Without freq-warping, it operates on a linear axis and does not produce the perceptually-scaled mel features that define it. The removal test: remove freq-warping and mel-filterbank stops operating as mel-filterbank.
Record identity
- Created
- Aug 13, 2026, 4:42 PM UTC
- Content hash
- e7b4d8e6ac19bb064c95f87fb05caf36d6924a258aa261c1a8e828d1d6b7b9f6