HRTF

Binaural 3D audio library for Processing 4. Loads head-related impulse responses from a SOFA file and convolves them with any sound source, using spherical-harmonic interpolation between measured directions. Works as an Effect on top of the Sound library, or standalone without it.

Written by Vojtech Leischner, 2026.

Use headphones. The binaural effect only works over headphones.

Install

In Processing, open Sketch > Import Library > Add Library, find HRTF under Contributions and install it. To install manually, download HRTF.zip from the latest release and unzip it into Documents/Processing/libraries/, then restart Processing.

The two bundled examples are available from File > Examples > Libraries > HRTF:

• BinauralWithSoundLib - a looping sample + oscillator routed through hrtf.process(source), orbiting a tilted ring so you can hear azimuth and elevation change.
• BinauralStandalone - the same renderer used without the Sound library, driven by a generated test tone.

Both examples share a single bundled KEMAR_s.sofa from the library’s data/ folder (HRIR data is never embedded in the jar; drop any other .sofa file into your sketch’s own data/ folder to use your own).

Quick start (Sound library)

import com.trackmeifyoucan.hrtf.*;
import processing.sound.*;

HRTF hrtf;
SoundFile file;

void setup() {
  size(600, 600);
  hrtf = new HRTF(this); // loads the first .sofa file in data/ in background
  hrtf.onReady(() -> println("ready"));
  file = new SoundFile(this, "voice_cloned.wav");
  file.loop();
  hrtf.process(file);
}

void draw() {
  hrtf.position(map(mouseX, 0, width, -180, 180), 0); // degrees
}

See the reference for the full API.

Data credits

Example HRIR data: KEMAR SOFA file via amini-allight/cipic-hrtf-database.

License

GPL-3.0-or-later, see LICENSE.

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