Overview
EN ISO 20109:2025 - Simultaneous interpreting - Equipment - Requirements (ISO 20109:2025) is a CEN-endorsed international standard that specifies equipment and performance requirements for simultaneous interpreting systems. It covers the quality of sound and image delivered to interpreters and from interpreters to audiences, regardless of physical locations of speakers, signers, interpreters and listeners. The standard replaces EN ISO 20109:2016 and was prepared by ISO/TC 37.
Key topics and technical requirements
The standard addresses practical, measurable requirements across audio, video and system interfaces. Major technical topics include:
- Sound requirements
- Digital input/output, sound pressure level, frequency response, distortion, noise and hum, and level consistency
- Hearing protection considerations and measurement (see normative Annex C)
- Image requirements
- Image quality and synchronization of sound and image
- Latency and location scenarios
- Requirements for events where parties are in the same room and where parties are in a separate location (networked or remote interpreting)
- Interpreting equipment and interfaces
- Hard consoles and soft consoles (interpreter control interfaces)
- Microphones (interpreter, speaker, ambient), headphones/headsets, and their behavior within the system
- Signed language interpreting
- Additional requirements for camera, microphone, background, and incoming audio/video to support signed-language interpreters
- Portable interpreting systems
- Microphones/transmitters, receivers/transceivers and transport systems for on-the-go deployments
- Operational and accessibility guidance
- Normative annexes on accessibility/usability of hard consoles and requirements for conference system operation
Applications and who uses this standard
EN ISO 20109:2025 is intended for professionals and organizations involved in multilingual and accessible events:
- Conference and event organisers ensuring reliable interpreting services
- AV integrators and system designers specifying equipment, cabling and network performance
- Manufacturers of interpreting consoles, transmitters, receivers, microphones and headsets
- Venue planners (public buildings, conference centers) setting up fixed or temporary interpreting facilities
- Accessibility coordinators and providers of signed-language services
- Interpreters and language service providers evaluating equipment ergonomics and audio/video quality
Related standards and guidance
- This edition supersedes EN ISO 20109:2016. It was prepared under ISO/TC 37 and adopted by CEN as EN ISO 20109:2025.
- For procurement or compliance, obtain the full text from national standards bodies or CEN/ISO to review normative details, test methods and measurement procedures.
Keywords: Simultaneous interpreting, interpreting equipment, ISO 20109:2025, EN ISO 20109:2025, sound quality, image synchronization, interpreting consoles, microphones, headphones, signed language interpreting, conference systems.