# Cochlear spiral spectrogram — visualizing music like the inner ear

**URL:** <https://discourse.processing.org/t/cochlear-spiral-spectrogram-visualizing-music-like-the-inner-ear/48267>\
**Category:** Gallery\
**Created:** [March 22, 2026, 2:17pm UTC](https://discourse.processing.org/t/cochlear-spiral-spectrogram-visualizing-music-like-the-inner-ear/48267 "2026-03-22T14:17:29Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![nivdvir](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@nivdvir](https://discourse.processing.org/u/nivdvir)\
**Post date:** [March 22, 2026, 2:17pm UTC](https://discourse.processing.org/t/cochlear-spiral-spectrogram-visualizing-music-like-the-inner-ear/48267/1 "2026-03-22T14:17:30Z")

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I built a music visualization system that maps audio frequencies onto a Fermat spiral, mimicking how the human cochlea processes sound.

**How it works:**

- 381 logarithmically-spaced frequency bins (20 Hz — 8 kHz)
- 
  - Mapped onto a Fermat spiral (r = √θ), following the cochlear structure
  - 
    - ISO 226 equal-loudness normalization for perceptual accuracy
    - 
      - Chromesthesia color mapping: frequency → hue (low red → high cyan)
      - 
        - 60 FPS with melodic trails, rhythm pulses, and harmonic auras

      - The result: you can literally see harmony. When notes align, the spiral lights up in symmetric patterns. Dissonance creates beautiful chaos.

    - Built in Python with scipy (FFT), PIL (rendering), and FFmpeg (encoding).

  - **Watch it in action:** [https://www.youtube.com/watch?v=66RiYBl7aQY](https://www.youtube.com/watch?v=66RiYBl7aQY)

- More examples on the channel: [youtube.com/@NivDvir-ND](http://youtube.com/@NivDvir-ND)

I’d love to hear thoughts from the creative coding community — especially anyone working with audio-reactive visuals or signal processing.