Dia dhaoibh!

It appears Irish phonology is even more complicated that I thought first. Mo cheist is about article an. As everybody knows it is pronounced /@/ or /@n/ before words starting with vowel. The thing what is known as well, is that /@/ is elided when immediately following or preceding a "full voice" stressed vowel. So for example if we have a sentence:

Tá an ghrian ag soilsiú

IPA: /tA: jr'i@n @sail'Su:/
Note: A - alpha, @ - schwa, S - sign of integral

is article audible at all over there? I mean /n/ is not pronounced before consonant /j/, and /@/ is merged with /A:/ or I got it wrong?

No, you didn't get it wrong. Of course, there are some options as to how to pronounced the sentence:

Tá an ghrian ag soilsiú /tA: jr´i@n @ sail'Su:
This is perfectly natural

Tá an ghrian ag soilsiú /tA:n jr´i@n @ sail'Su:
This is also natural, with the @ in an merging with the long A: but the n remaining

Tá an ghrian ag soilsiú /tA: @ jr´i@n @ sail'Su:
This is no longer natural speech, but well suited for reading aloud or reciting poetry

Tá an ghrian ag soilsiú /tA: @n jr´i@n @g sail'Su:
This would be bad... :-)