SoundSketcher experiments

Smooth, Rough, Sharp

Listeners rated 30 sounds on three independent perceptual scales — smoothness, roughness, and sharpness. The ratings validate the timbre categories behind the Bouba/Kiki sound–shape study.

29listeners

30sounds

3rating scales

Try the task See results

How the data was collected

Participants listened over headphones and moved three independent sliders from “not at all” to “very”. Sound order was randomised and replays were unrestricted.

1. Hear the sound

Each participant heard all 30 sounds in a randomised order, with no time limit and free replay.

2. Rate three qualities

For each sound, three sliders (0–100) captured smoothness, roughness, and sharpness independently.

3. Aggregate responses

Ratings were aggregated per sound to give a perceptual profile used as ground truth for acoustic modelling.

Try the task

Pick one of the example sounds, play it, set the three sliders to match what you hear, then submit to compare your profile with the group.

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Smoothness

Not at allVery

Roughness

Not at allVery

Sharpness

Not at allVery

Your answer vs the listeners

Play the sound and submit your rating to see how it compares.

Key findings

The three intended categories separate cleanly in perceptual space. Smooth sounds sit at high smoothness and low sharpness; sharp sounds cluster at the top; rough sounds occupy the middle with the largest roughness ratings.

Reliability of the group mean on every scale (Cronbach’s α across listeners).

Smoothness vs roughness across the 30 sounds: near-opposites.

Smoothness vs sharpness: smoother sounds are heard as less sharp.

Roughness vs sharpness: only weakly related, distinct qualities.

Smooth Rough Sharp

Horizontal: smoothness. Vertical: sharpness. Bubble area: roughness. Mean ratings per sound (0–100). Click a bubble to listen.

Publication

CMMR 2025 · London

Between Bouba and Kiki lies Grougi: Modelling the Rough Middle Ground of Sound–Shape Correspondences

Asterios Zacharakis, Konstantinos Velenis & Emilios Cambouropoulos

Bouba/Kiki showcase

These ratings form Experiment 2 of the paper: a semantic validation confirming that the smooth, rough and sharp stimulus categories correspond to distinct perceptual dimensions.

Cite this work (BibTeX)

@inproceedings{Zacharakis2025Grougi,
  author    = {Zacharakis, Asterios and Velenis, Konstantinos and Cambouropoulos, Emilios},
  title     = {Between {B}ouba and {K}iki lies {G}rougi: Modelling the Rough Middle Ground of Sound--Shape Correspondences},
  booktitle = {Proceedings of the 17th International Symposium on Computer Music Multidisciplinary Research ({CMMR})},
  year      = {2025},
  address   = {London, United Kingdom}
}