SoundSketcher experiments

Indefinite-Pitch Sounds

A listening task for sounds that do not offer a stable fundamental frequency: noise bands, clusters, environmental textures, and other sounds whose pitch height is perceptually real but acoustically ambiguous.

48listeners

19non-harmonic sounds

1sine-matching task

Try the task See results

How the data was collected

Participants listened over headphones and matched each sound to a sine tone by adjusting its frequency along a logarithmic 40–6000 Hz scale.

1. Training examples

Participants first used three training examples to learn the interface and set a comfortable listening level.

2. Sine-tone matching

For each study sound, they adjusted a sine tone until it matched the perceived pitch height of the sound.

3. No-match option

When no convincing pitch match was available, they could mark the trial as no match.

Try the task

Pick a stimulus, play it, then hold the frequency slider to hear the sine tone and move it until both sounds share the same pitch height.

Loading sounds...

Study set 0 of 0

Sinusoidal match 440 Hz

Sine volume 80%

Hold the slider to hear the sine tone, then release to stop it.

Stimuli

Key findings

Listeners can make reliable pitch-height distinctions even when periodic cues are weak or absent.
A loudness-weighted spectral centroid is a useful predictor of perceived pitch height in these sounds.
Sounds with greater spectrotemporal variability tend to produce less accurate or more dispersed matches.

Result figures

Pitch matches per sound — Distribution of listener pitch matches per stimulus, highlighting agreement and dispersion across sounds.

Spectral centroid versus perceived pitch with stimulus labels — Stimulus-level pitch judgments against spectral centroid, with compact stimulus labels.

Perceived pitch versus loudness-weighted spectral centroid — Median perceived pitch height plotted against loudness-weighted spectral centroid, showing the main acoustic-perceptual relationship.

Mixed-effects model marginal effect — Mixed-effects model view of the contribution of loudness-weighted spectral information to pitch-height judgments.

Publication

JASA Express Letters · 2026

Beyond fundamental frequency: Pitch height judgments in Indefinite-Pitch sounds

Konstantinos Velenis, Asterios Zacharakis & Emilios Cambouropoulos

DOI 10.1121/10.0043569 Participant information (PDF)

SoundSketcher needs a vertical pitch-like mapping for electroacoustic and environmental sounds, not only for harmonic tones. This experiment supports a practical idea: when fundamental frequency is unreliable, perceptually weighted spectral information can still guide graphical placement.

Cite this work (BibTeX)

@article{Velenis2026,
  author  = {Velenis, Konstantinos and Zacharakis, Asterios and Cambouropoulos, Emilios},
  title   = {Beyond fundamental frequency: Pitch height judgments in Indefinite-Pitch sounds},
  journal = {JASA Express Letters},
  volume  = {6},
  number  = {4},
  year    = {2026},
  doi     = {10.1121/10.0043569}
}