New International Ergonomics Standards Address Visual and Auditory Design

Described as "solution documents," ISO has released two new ergonomics standards targeting visual and auditory design issues. The first, ISO 24502:2010, Ergonomics – Accessible design – Specification of age-related luminance contrast for coloured light, "will help make products, signs and displays more accessible to older persons and those with disabilities – and the rest of us," according to ISO. The ISO web site provides this detailed description:

ISO 24502:2010 specifies the age-related luminance contrast of any two lights of different colour seen by a person at any age, by taking into account the age-related change of spectral luminous efficiency of the eye.

… provides a basic method of calculation that can be applied to the design of lighting, visual signs and displays. It applies to light, self-luminous or reflected, in visual signs and displays seen under moderately bright conditions called photopic vision and whose spectral radiance is known or measurable. It does not apply to light seen under darker conditions called mesopic or scotopic vision.

… specifies the luminance contrast for people aged from 10 to 79 years who have had no medical treatment or surgery on their eyes that may affect their spectral luminous efficiency.

… does not apply to visual signs and displays seen by people with colour defects whose spectral luminous efficiency is different from those with normal colour vision, nor those seen by people with low vision.

The second new standard, ISO 24501:2010, Ergonomics – Accessible design – Sound pressure levels of auditory signals for consumer products, according to ISO, "aims to determine an appropriate sound level range of auditory signals, so that all users, including people with age-related hearing loss, can hear them properly against interfering sounds." The ISO provides this detailed description:

ISO 24501:2010 specifies methods for determining the sound pressure level range of auditory signals so that the users of consumer products, including people with age-related hearing loss, can hear the signal properly in the presence of interfering sounds.

Auditory signals, in ISO 24501:2010, refer to sounds with a fixed frequency (also called beep sounds) and do not include variable frequency sounds, melodic sounds, or voice guides.

… is applicable to auditory signals which are heard at an approximate maximum distance of 4 m from the product, as long as no physical barrier exists between the product and the user. It is not applicable to auditory signals heard through a head receiver or earphones, or to those heard with the ear located very near to the sound source because of the interference of the head with sound propagation.

… does not specify the sound pressure level of auditory signals regulated by other statutes, such as those for fire alarms, gas leakages and crime prevention, nor does it specify auditory signals particular to a communication tool such as telephones.

… does not specify auditory danger signals for public or work areas which are covered in ISO 7731, ISO 8201, and ISO 11429.

The two new standards part of a set of accessible design standards that help make accessible products, services and environments encountered in all aspects of daily life, as well as in the consumer market. They adopt the principles of accessible design presented in ISO/IEC Guide 71:2001, Guidelines for standards developers to address the needs of older persons and persons with disabilities.

You can learn more or purchase the standards by visiting the ISO web site.

This article originally appeared in The Ergonomics Report™ on 2011-02-03.