Building Acoustics TU/e

Autumn updates on CHORAS

Maarten Hornikx
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CHORAS is a web-based user interface that allows users to run open-source acoustic simulation methods directly in the browser. It brings multiple open-source acoustic simulation software together in one place — making your (and others’) open-source room acoustics methods accessible through a unified UI.

Whether you’re a student, researcher, consultant, material manufacturer, developer, or simply acoustics-curious, CHORAS is built by and for the room acoustics community. CHORAS is currently being developed Eindhoven University of Technology, and we target to foster a sustainable community around it. The updates of this article reflect insights of this journey of the past months.

More information can be found in a conference paper of Forum Acusticum in Málaga, in which the CHORAS concept was presented, and in a noise news international paper.

CHORAS can be found on Github.

1. A Fresh User Interface

We recently redeveloped the CHORAS interface and gave it its own visual identity. The new UI places the open-source simulation methods more centrally and has been designed for intuitive use and smooth navigation. This update marks an important step toward making open-source room acoustics simulations more accessible. The UI can be run in the browser using a Docker image. Interested to test the current version of CHORAS? The installation instructions can be found here.

2. Developer Workshop in Eindhoven

The CHORAS philosophy is simple: a single UI for multiple open-source simulation methods. While the frontend and backend are currently developed under the coordination of the TU/e Building Acoustics team, any backend room acoustics simulation tool can potentially be connected. CHORAS already supports the Diffusion Equation (DE) and Discontinuous Galerkin (DG) methods developed at TU/e Building Acoustics, and we target to expand the ecosystem. To accelerate this, we organised a developer workshop on 25–26 September in Eindhoven. Researchers from several European institutes worked on integrating their methods into CHORAS. The workshop strengthened the understanding of CHORAS’s role in the community and sparked enthusiasm for collaboration. The methods currently being linked include:

In parallel, we are also working on integrating pyroomacoustics.

3. User Workshop at ASSA 2025

During the Autumn School Series in Acoustics (ASSA 2025), one full day was dedicated to CHORAS. The workshop had a twofold goal:

  1. Let participants explore CHORAS and simulate the ASSA school room without prior knowledge of the material properties.
  2. Gather feedback and ideas from the participants to continue building the platform together.

Participants engaged deeply with the interface, and the feedback ranged from imaginative ideas to precise, actionable suggestions — the kind of input that keeps CHORAS community-driven.

4. New Feature Development

On 20–21 November, the TU/e Building Acoustics team held two away-days dedicated to designing and implementing new CHORAS features.

Topics included material handling, new decision-support tools to help users select the right open-source simulation method, improved geometry handling, and integrating existing and newly developed benchmark rooms. These additions will enhance both the usability and scientific transparency of CHORAS.

5. More to Come!

CHORAS is developed as part of the Dutch NWO (Dutch Research Council) OTP project “A new era of room acoustics simulation software: from academic advances to a sustainable open-source project and community.” Our long-term goal is to build a sustainable, community-driven platform for sharing open-source research software. We are currently shaping the sustainability model for this purpose — more on this will follow!

The good news: anyone can be part of CHORAS, as a user, developer, or follower. Stay connected by following our LinkedIn page. Don’t hesitate to reach out to us!

People of CHORAS

The CHORAS community is about people, so let’s name them!

The team that has contributed to the CHORAS development includes: Maarten Hornikx Silvin Willemsen Marco Berzborn Alexander Serebrenik Alexander Nolte Ajat Darojat Fachri Hawari Radhea Amardika

Developers working on integrating their open-source acoustic simulation methods to CHORAS: Nikolas Borrel-Jensen Nicolas Fortin Hossein Firooz Zeyu Xu Anjana Rajasekhar Ilaria Fichera Huiqing Wang

Active CHORAS users/contributors during workshops: Dingding Xie Cédric Van hoorickx Jelle Langedijk Judith van Enckevort Casper de Ruiter, MSc Lauri Savioja Maciej Jasiński Remy Wenmaekers Luc Dijkman Niels van Drunen Christopher Sittl Tim Schellekens Jay Au-Yeung Michail Evangelos Terzakis Constant Hak Lavínia Paganini Lynn Passlack