ISO 24620-3:2021 PDF

Overview

ISO 24620-3:2021 - part of the ISO 24620 series on Language Resource Management - Controlled Human Communication (CHC) - defines the basic principles and a methodology for designing formally defined, controlled oral communication (COralCom) systems. The standard focuses on reducing phonetic interferences and confusions (e.g., phoneme confusion, homophony, quasi‑homophony, co‑articulation) within and between languages, especially in multilingual or stressful situations. It applies to oral exchanges among native and non‑native speakers without speech or hearing impairments and excludes sign languages.

Key topics and technical requirements

• Scope & limitations
  • Covers only oral speech between unimpaired speakers/listeners.
  • Excludes sign languages and speech/hearing impairments.
• Principles for controlled oral systems
  • Use of distinctive phonetic features to characterize phonemes.
  • Abstraction of phoneme inventories and relationships to prevent ambiguity.
• Methodology
  • Procedures for deriving phonemes from distinctive features and mapping to words.
  • Rules to avoid confusion: catalogues of possible linguistic phenomena (conditions) and corresponding operators (actions) to mitigate risk.
  • Algorithmic representation of rules to support automated or computerized implementation.
• Analytical tools and annexes
  • Examples of interferences, distinctive features, paronyms.
  • Annex for calculation of phoneme proximity - useful for assessing phonetic similarity.
  • Information system guidance for controlled languages.
• Intended outputs
  • A formal specification for a controlled oral vocabulary and phraseology that minimizes perceptual confusions.

Practical applications and users

• Primary use cases
  • Safety‑critical communications: aviation, maritime, emergency services, industrial control rooms.
  • Multilingual workplaces where misheard commands can cause harm or loss.
• Secondary use cases
  • Training and evaluation of operators and first responders.
  • Human‑robot interaction and voice interface design where robust oral understanding is required.
• Who should use it
  • Standards architects, language engineers, UX and voice interface designers.
  • Safety managers, regulatory bodies, training organizations, and developers of voice‑controlled systems and robots.

Practical benefits

• Reduces miscommunication and operational errors in high‑risk contexts.
• Provides a repeatable, evidence‑based method to design constrained oral vocabularies.
• Supports interoperability where precise oral commands are critical across languages.

Related standards

• Part of the ISO 24620 CHC series; see ISO resources for other parts and ISO/TC 37 (Language and terminology) outputs for related controlled language guidance.

Keywords: ISO 24620-3:2021, Controlled Human Communication, COralCom, controlled oral communication, phoneme confusion, homophone, language resource management, safety‑critical communication.