Intelligibility of ECS

摘要

Standard methodologies for quantitatively measuring intelligibility have been around for some time. The idea of quantitatively measuring fire emergency voice evacuation communication was first introduced in the 1999 edition of NFPA 72.There were proposals to require a specific measured intelligibility of 0.7 on the common intelligibility scale (CIS) for the 1999 edition,rnbut the NFPA membership rejected the incorporation of the requirement in the code. The Annex to the 1999 edition provides guidance for those wanting to perform quantitative measurement of intelligibility and references IEC 60849, sound systems for emergency purposes, published by the International Electrotechni-cal Commission.