I work in the call centre space which deals with voice recognition IVRS. If there is no voice pack available for your specific country, a number of 'utterances'

I work in the call centre space which deals with voice recognition IVRS. If there is no voice pack available for your specific country, a number of 'utterances' are collected to train the recogniser. So, yes, accents are used in the voice recognition software that I'm familiar with.