ISO 24500:2010

Overview

ISO 24500:2010 - Ergonomics - Accessible design - Auditory signals for consumer products defines how simple fixed‑frequency auditory signals (commonly “beeps”) should be designed and used as feedback in consumer products. The standard targets usability and accessibility so that people - including older adults and persons with visual or hearing impairments - can reliably hear and understand signals indicating operations, completion, or faults. It applies to general fixed‑frequency signals (not melodic or variable‑frequency tones) and excludes emergency public/work alarms, fire/gas alarms, telephones, chimes, voice guidance, and professional machinery.

Key topics and requirements

• Signal categories and meanings
  • Operation confirmation signals (reception/start, stop, starting position)
  • End signals (completion of an action)
  • Caution signals (weak and strong; indicate incorrect operation or abnormal conditions)
• Temporal patterns
  • Specific ON/OFF timing patterns are prescribed for each signal category (e.g., short “pip” for reception, longer “peep” for stop, repeated patterns for end and caution signals). Patterns are designed to be distinct and not easily confused.
• Frequency and timbre
  • Fundamental frequency should not exceed 2.5 kHz to accommodate age‑related hearing loss.
  • Products should offer several frequency options and preferably complex sounds (multiple harmonics) because these are more detectable by people with impaired hearing.
• Volume control and repetition
  • Users must be able to adjust volume to suit hearing ability and ambient noise.
  • Caution signals repeat only while the cause exists; strong caution should continue until user intervention.
  • Except for caution signals, users should be able to turn auditory signals off.
• Scope limitations
  • ISO 24500 does not set sound pressure levels - see ISO 24501 for level determination and measurement methods.

Applications and users

ISO 24500 is intended for designers, product developers, human factors/ergonomics specialists, accessibility experts, and manufacturers of consumer products such as household appliances, consumer electronics, toys, health‑care devices, and office equipment. It helps ensure auditory feedback is:

• Recognizable and non‑confusing in multi‑device environments
• Usable by older adults and people with sensory impairments
• Consistent across product families for predictable interaction

Examples from the standard: a washing machine beep for an open lid, an oven stopping signal for overheating, or a tape recorder rewind completion tone.

Related standards

• ISO 24501 - Sound pressure levels of auditory signals for consumer products (levels and measurement)
• ISO 7731, ISO 8201, ISO 11429 - Auditory danger and emergency signals for public/work areas
• ISO/IEC Guide 71 and ISO/TR 22411 - Accessible design guidance for older persons and people with disabilities

Keywords: ISO 24500:2010, auditory signals, accessible design, ergonomics, consumer products, beep sounds, caution signals, operation confirmation signals, end signals, sound pressure levels.