Sonic Catnip 0.2

sample-exact port of Akira Brown's Pure Data patch sonicatnip0.2.pd (2025)

A per-sample AudioWorklet reimplementation of Akira Brown's original instrument — every Pd object reproduced with its literal sample math. Sonic Catnip project — Armstrong, Brown & Whalley, University for the Creative Arts.

pd dsp <- compute audio. Put this on for your cat at a low volume.

Pitch Class + Purr

purr~ 26.3 Hz sub-bass pulse · 27 bpm respiration · felt more than heard
pitchclass~ Shepard melody · major scale

Chords + Drone

cloud_oscillator detuned triad · root/third/fifth
felixfilterbank~ filtered fifth · 0 + 7

master

; what your cat is hearing

In December 2020 a TikTok trend revealed that many domestic cats responded affectionately to "Window" by The Album Leaf, whose opening synth carries a major-tenth interval. David Teie attributed the reaction to that interval's resemblance to the biphonation of mice — a low vocal tone and a higher whistle sounding together [Teie 2021]. Building on the "ecologically-relevant music" framework of Snowdon, Teie & Savage [2015], Sonic Catnip synthesises music from acoustic features that matter to cats rather than to humans.

purr band · 25–30 Hz
A pulse train at a 26.3 Hz fundamental (Peters 2002), amplitude-modulated by a resting respiration rate of 27 breaths/min (Dijkstra 2018). Cat larynges produce these frequencies without neural input (Herbst 2023).
ecological band · ~1.34 kHz
The average pitch cats prefer in species-appropriate music — about two octaves above human control pieces and an octave above cat vocalisation (Snowdon, Teie & Savage 2015).
mouse band · 4–8 kHz
Defensive mouse squeaks sit near 3.8 kHz, within the 4–8 kHz range where a cat's hearing is most sensitive — the prey signature behind the "Window" effect (Ruat 2022).

Each generative voice picks a slow tempo (default 43–53 bpm) and moves through a diatonic scale, while the pitch-class voice spreads each note across every octave (a Shepard-tone-like stack) to fill the acoustic niche described by Bernie Krause's concept of biophony (Krause 2013). Every cat is an individual — some approach the sound, some ignore it; both are normal. Stop if your cat seems agitated.

; references

  1. Blistein, J. (2021) Why are cats on TikTok getting really into mid-2000s ambient music? Rolling Stone.
  2. Dijkstra, E., Teske, E. & Szatmári, V. (2018) The Veterinary Journal 234, 92–101.
  3. Herbst, C. T. et al. (2023) Current Biology 33(21), 4727–4732.
  4. Krause, B. (2013) The Great Animal Orchestra. Profile Books.
  5. Mira, F. et al. (2015) J. Feline Med. Surg. 18(2), 150–159; (2016) 18(8), 673–678.
  6. Peters, G. (2002) Mammal Review 32(4), 245–271.
  7. Ruat, J. et al. (2022) iScience 25(7), 1–20.
  8. Snowdon, C. T., Teie, D. & Savage, M. (2015) Applied Animal Behaviour Science 166, 106–111.

; about this web version

The original Sonic Catnip instrument is a Pure Data patch, sonicatnip0.2.pd, built by Akira Brown (2025) with the custom abstractions purr~, pitchclass~, cloud_oscillator and felixfilterbank~ shown above as object boxes. This page runs a sample-exact AudioWorklet port of that patch — each Pd object reproduced with its literal per-sample math (naive phasors, exact cos~/clip~/pow~ waveshaping, one-pole hip~/lop~ filters) — so it can run in any browser without installing Pure Data. Made for the chapter "Sonic Catnip: Composing Biphonation through Pure Data" in Music and Cats (ed. Schoop).

Open-source / open-access · no audio leaves your device — everything is synthesised locally.