The A becomes An for the same reason as the linking R <a href="https://en.wikipedia.org/wiki/Linking_and_intrusive_R" rel="nofollow">https://en.wikipedia.org/wiki/Linking_and_intrusive_R
As a non-native now living in UK I noticed this R sound in some accents. Someone said 'Java (r)Options' which when I asked they didn't even realise they were adding it. Both this R and N in an seem to be used break the continuity of vowels between words.
smusamashah · · focus · HN ↗
As a non-native now living in UK I noticed this R sound in some accents. Someone said 'Java (r)Options' which when I asked they didn't even realise they were adding it. Both this R and N in an seem to be used break the continuity of vowels between words.