Ensuring clear and intelligible dialog is a key quality objective throughout media production and distribution. Nevertheless, audiences across television, radio, streaming, podcasts, and other speech-based formats sometimes still struggle to understand spoken content. Traditional audio measurements such as level and loudness provide essential information about an audio signal, but they do not directly indicate how easily listeners can understand speech.

Fraunhofer IDMT’s AI-based LEAP technology (Listening Effort Prediction for Acoustic Parameters) takes a different approach. It assesses perceived dialog intelligibility by estimating the listening effort required to understand spoken content. This provides audio professionals with an objective indication of whether dialog can be understood easily.

Consistent results across the media workflow

As LEAP is integrated into a range of professional audio products, the providers identified the need to ensure that users receive comparable results regardless of which product or platform they are using. When products use the same underlying algorithm, differences in signal processing, downmixing, scaling, smoothing, terminology or visualization could affect how measurement results are presented and interpreted.

To enable interoperability between different tools, Fraunhofer IDMT and the manufacturers, working together as LEAP Meter Manufacturers Group (LMMG), developed the LMMG Dialog Intelligibility Implementation Agreement. It standardizes key aspects of LEAP-based implementations.

This includes the use of “Dialog Intelligibility” as the common terminology and “DIU” (Dialog Intelligibility Unit) as the unit for customer-facing measurements. LEAP results are mapped to a common scale from 0 to 100 DIU. Higher values indicate better dialog intelligibility and lower listening effort. The agreement also specifies shared reference thresholds and color ranges as well as requirements for signal processing, downmixing, smoothing and the handling of non-dialog content.

Prof. Dr. Jan Rennies-Hochmuth, Head of Personalized Hearing Systems at Fraunhofer IDMT, explains: “Our longstanding collaboration with these manufacturers has already brought LEAP technology into a range of professional audio products. The shared implementation framework is an important next step toward maintaining high dialog intelligibility seamlessly across the entire workflow of audio professionals.”

A production can therefore be monitored, refined in post-production and checked during quality control with tools from different manufacturers while retaining the same underlying technology, scale and measurement principles.

The manufacturers behind the LMMG

The LMMG brings together the professional audio manufacturers NUGEN Audio, RTW, Steinberg, and Telos Alliance. Fraunhofer IDMT supports the initiative as the developer of the underlying LEAP technology.

The first version of the LMMG Dialog Intelligibility Implementation Agreement establishes the basis for consistent real-time measurement. As practical experience with the technology grows, the group plans to explore ways to assess dialog intelligibility across an entire program or media asset. Such measurements could provide broadcasters, streaming services and content producers with additional quality-control tools and establish dialog intelligibility as an important complement to measurements such as loudness.

See dialog intelligibility in action at IBC2026

The upcoming International Broadcasting Convention (IBC2026), taking place in Amsterdam from September 11 to 14, offers an ideal opportunity to take a closer look at the growing importance of dialog intelligibility in media. Two separate initiatives aim to make speech in broadcast and streaming content easier to understand:

On the one hand, as part of the IBC2026 Accelerator Media Innovation Programme, Fraunhofer IDMT is involved in the project “Crystal Clear: Boosting Speech Intelligibility in Media.” Together with broadcasters, industry organizations and research partners, the project explores practical and consistent approaches to measuring and improving dialog intelligibility across broadcast and streaming.

On the other hand, at the booths of the LEAP Meter Manufacturers Group, visitors will also be able to experience dialog intelligibility measurement in professional audio tools and learn more about the common implementation framework.