ISO 24504 pdf download Ergonomics — Accessible design — Sound pressure levels of spoken announcements for products and public address systems
This International Standard specifies methods to determine an appropriate sound pressure level rangefor spoken announcements in environments where ambient noise is less than 80 dB.The specifiedmethods follow the concepts of ISOIEC Guide 71 and includes consideration of older persons withlecreased hearing ability to determine sound pressure levels of spoken announcements, The spokenspeech levels that are specified in this International Standard are for products and public-addresssystems. To improve the accessibility and usability of products, spoken announcements must not onlybe audible but also presented at comfortable speech levels.
The target products that present spoken announcements are consumer products such as electronic homeappliances, information and communication technology services, and products providing services forgeneral users in public facilities indoors and outdoors such as train stations, airports, meeting roomsamusement parks,and fairs.
This International Standard is not applicable to products providing private information such asautomated teller machines in public spaces.
This International Standard is applicable when a loudspeaker producing a spoken announcement isocated a short distance from the user in an environment where the sound pressure level with a standardfrequency weighting A ofambient noise does not exceed 80 dB.This lnternational Standard is applicableto spoken announcements that are audible to persons with normal hearing for their age when presentedby a target product under quiet and anechoic conditions. This International Standard is applicable forooth recorded voice and synthetic speech announcements.
This International Standard does not specify sound pressure levels of spoken announcements forsystems with automatic sound pressure level control to compensate for fluctuating ambient noise levels.This International Standard is not applicable to spoken announcements heard through headphones orearphones, or to spoken announcements heard with the ear close to the speech sound source, such asin ear speakers specified in lEC 60268-7. This International Standard considers only the audibility ofspeech and not the process of speech understanding
This International Standard does not specify the sound pressure levels of spoken announcementspresented in emergency situations such as signals for fire alarms, gas leakage, and crime preventionthose are covered in ISO 7240-16 and ISO 7240-19. This International Standard does not specify thesound pressure levels of spoken announcements in automobiles; those are covered in ISO 15006.
NOTE 1A spoken announcement presented in a repetitive manner from a product such as electronic homeappliance is presumed to be heard as an auditory sign but not as a message and is therefore usable with a lowersound pressure level of the spoken announcement than this International Standard specifies.
NOTE2 lt is known that the word recognition performance of native speakers of the language of theannouncement is better than that of non-native speakers.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application, For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.