Hola, I'm Sofia.

Audio engineer and researcher from Mexico City, based in Graz, Austria. I turn data into sound and build tools for doing it.

I'm a PhD candidate and University Assistant in Musical Acoustics at the Institute of Electronic Music and Acoustics (IEM), University of Music and Performing Arts Graz. My research is about sonification and the software we use to create sonifications.

Our ICAD 2025 paper on sonification software won the Best Student Paper Award, and I've received the Audio Developer Conference Diversity Scholarship twice.

Before Graz I did an MSc in Sound and Music Computing at the Universitat Pompeu Fabra in Barcelona, Spain, where I modelled analog synth oscillators with neural networks. Before that, I spent a few years in studios and on stages in Mexico.

Now

PhD & University Assistant, IEM · KUG Graz

From

Mexico City

Interests

Music, machine learning for audio, DSP, acoustics, sonification, sonic interaction design

Speaks

Spanish (native), English (C2), German (B1), Catalan (A2)

Off the clock

Mostly something food related. I also keep a garden going, take photos (some are in Fotos), and spend a lot of time playing games.

Favourite game

Red Dead Redemption 2

Favourite film

Star Wars: The Empire Strikes Back

Favourite TV shows

Peaky Blinders & Modern Family

Favourite band

Nothing But Thieves

Favourite song

Inhaler, Foals

Publications

1. 2026

   Rule-Based Framework for Automated Audification forthcoming

   S. Vallejo Budziszewski, K. Gross-Vogt, R. Höldrich

   Proc. 31st International Conference on Auditory Display (ICAD 2026), Bielefeld, Germany

2. 2026

   Natural Language Interaction for Morphology-Aware Audification forthcoming

   S. Vallejo Budziszewski, K. Gross-Vogt

   Proc. Forum Acusticum Euronoise 2026, Graz, Austria

3. 2025

   Legacy, active & future software tools in sonification research ★ Best Student Paper

   S. Vallejo Budziszewski, K. Gross-Vogt

   Proc. 30th International Conference on Auditory Display (ICAD 2025), Coimbra, Portugal

   Abstract

   This article provides an overview of the development of active and legacy software tools for sonification. A collection of tools has been compiled and categorized according to research trends suggested in this paper, for the period 1990 to the present. The tools are categorized into five main user scenarios, highlighting key features of sustainable software, and identifying major challenges. The article also outlines a research agenda that considers the application of machine learning for generating intuitive and adaptive sonifications.

   PDF DOI Dataset (tool survey) Tool catalogue BibTeX
4. 2024

   Modeling the voltage controlled oscillator using augmented neural networks

   S. Vallejo Budziszewski

   MSc thesis, Sound and Music Computing, Music Technology Group, Universitat Pompeu Fabra

   Summary

   A digital model of the VCO of the analog RSF Kobol synthesizer, built with augmented neural networks. The model learns how the oscillator's frequency behaves and how it responds to control voltage, and a phase integrator turns that into a waveform.

   Zenodo Code

Awards

• 2025Best Student Paper Award, ICAD 2025, Coimbra
• 2× Diversity Scholarship, Audio Developer Conference (ADC)

Talks & workshops

• Jul 2025Sonification of Air Particles in Graz. Workshop at the SMC 2025 Summer School, with Katharina Groß-Vogt. Participants sonified nano- and micro-particle data from Graz's air in SuperCollider and Pure Data.
• Sep 2026Forum Acusticum Euronoise 2026, Graz. Paper presentation.
• Jul 2026ICAD 2026. Paper presentation.
• Jul 2025ICAD 2025, Coimbra. Paper presentation.
• 2023Measure of Music hackathon & conference. Project presentation (Fan-Turnout).

• 2026 · JUCE · VST3 / AU · beta

  Steiner-Parker Filter

  A 1970s diode filter as a plugin. A wave digital model of the Steiner-Parker VCF, built from a real schematic: ten diodes, three inputs for low-pass, band-pass and high-pass, and resonance that sings. Free and open source.

  Download (macOS) Read the post Code

• 2026 · Web Audio · live data

  Overhead

  The sky above you, composing itself. Solar wind, aurora, cosmic rays, gravitational-wave alerts and the ISS, streamed live into one piece that never plays the same twice.

  ▶ Listen live Code

• 2026 · Web Audio · live data

  Takt

  Rail networks as strings. Each route is a string tuned by its length, and trains pluck the lines they cross. Late trains drift out of tune. Live from 15+ cities, Tokyo included.

  ▶ Listen live Code

• 2026 · IEM Graz · ICAD 2025

  Sonification Tools

  A living catalogue of 80+ sonification tools, active and legacy, from our award-winning ICAD 2025 survey. Search, filter, and submit tools that are missing.

  Open catalogue Paper

• 2026 · Web Audio · Pure Data

  What Is Left

  Every country starts as the same choir of 160 voices. What you hear missing is what was taken: the killed, the displaced, the disappeared.

  Code

• 2025 – · PhD project · IEM Graz

  Sonification Studio

  My PhD project. A tool that turns data into sound by combining machine learning with expert mapping rules from the sonification literature, building on our ICAD survey of sonification software.

  First release

• 2024 – · IEM Graz

  The Letter Day Project

  A pen with sound feedback that helps first graders learn to write, linking each letter's shape to its sound.

  Project

• 2024 · MTG · PyTorch

  Kobol RSF VCO

  My MSc thesis: a neural network that emulates the oscillator of the analog RSF Kobol synth.

  Thesis Code

• 2023 – 24 · MTG & BMAT

  LoudSense

  Estimating how audible background music is in TV and film, for fairer royalties.

  Project Code

• 2023 · Wekinator, Processing

  Transcribe ASL

  Real-time American Sign Language to text with interactive machine learning.

  Code

• 2023 · Measure of Music

  Fan-Turnout

  Hackathon project on music data and audience turnout.

  Code

• 2023 · UPF · DNNs

  Groove estimation

  Can a deep network tell how much a track grooves? Trained on the Tropical Genres Dataset.

  Code

• 2023 · Pure Data

  Markov chords

  Markov chains that write chord progressions in any major key and play them through Serum.

  Patch

• 2023 · Pure Data

  Consciousness

  Final lab for the MTG course on computational music creativity.

  Video

• 2023 · Pure Data

  Ambient Generator

  Granular ambient beds from two chords, plus a TR-808-style kit.

  Video Patch

• 2023 · Pure Data

  Random Tone Generator

  A stochastic tone plugin with an effects chain for atmospheric textures.

  Video Patch

Posts

• 2026-11Modeling the Steiner-Parker filter
  How I turned a 1970s diode filter into a wave digital model and a VST3/AU plugin, with the schematic, the build, the tests, plots and audio.

Teaching

• 2024 –Teaching Assistant, IEM · Kunstuniversität Graz
  Musical Acoustics (strings, pipes, resonances, rooms and hearing) and courses in Sonic Interaction Design.
• 2025Workshop lead, SMC 2025 Summer School, Graz
  Sonification of Air Particles in Graz, with Katharina Groß-Vogt.
• 2023Teaching Assistant, Universitat Pompeu Fabra
  Signals and Systems I: intro to DSP for 2nd-year engineering students.
• 2021 – 22Teaching Assistant, REC Música, Mexico City
  Sound design for video games, machine learning for music.

Photos

Say hi

For research, collaborations, students or a mix/master.

• Emailvallejo@iem.at
• GitHubsofiavallejob
• LinkedInsofiavallejo
• OfficeIEM, Inffeldgasse 10/3, Graz