What is mean by Articulation in(AI!! Articulation Index (AI that
is "idely used in the automot
industry as a #o"er$ul #arameter to %uali$y&%uanti$y the and
high $re%uency s#ectra associated to the internal novehicles.
'he Articulation Index or AI gives a measure o$ the
intellhearing s#eech in a given noise environment. 'he
basicinter#retation o$ the AI value is the higher the value
then
easier it is to hear the s#oken "ord. 'he AI value is
ex#reeither as a $actor in the range ero to unity or as a #erce
A %uantitative measure o$ the intelligibility o$ s#eech)
th#ercentage o$ s#eech items correctly #erceived and reco
An articulation index o$ *++, means that all s#eech
canunderstood- +, means that no s#eech can be understoo
7/24/2019 Articulation Index
3/5
Ho" to calculate AI!! Its genera$ormula'he basic method o$
evaluating AI uses the conce#t o$ a
idealised s#eech s#ectrum and the third octave s#ectruo$ the
background noise. /ssentially i$ a #articular backgnoise third
octave s#ectrum level is above the corres#onidealised s#ectrum
level then the contribution to AI is eho"ever the di0erence is
#ositive then it "ill make acontribution. Ho"ever- i$ the di0erence
is greater than 1the contribution is 1+dB. /ach contribution is
multi#lied
"eighting $actor s#eci2c to the #articular third octave basum o$
all the contributions is the AI value.
