Translation:Their house is terribly far away.
It is more-or-less impossible on a course like this when you keep on meeting new accents. How do you know that they way they pronounce one is not the way someone else pronounces the other. But generally the a in aca is as in papa but the ai in aice is as in take, or occasionally as in bike.
The meaning of falbh has developed somewhat over time:
Dwelly (1911) - Go, begone, walk. 2 Depart. 3 Retire. 4 Perish.
Mark (2003) - depart, go away, leave
AFB (current) - leave, depart, go away
It still has a sense of 'going' at least as much as 'away' and I would say that even today, 'going away' give a better sense of the Gaelic than 'leave'. Indeed Mark gives
[tha] Màiri a’ falbh le Iain 'Mary is going with Ian? (i.e. going out with, as a courting couple)'
bha a shùilean a’ falbh air feadh a’ choithionail 'his eyes were going throughout the congregation'
So I would understand it as it being a long way to get there.
Note that although 'leave' is often the best translation, it can lead to big mistakes as it is not the correct Gaelic for 'leaving someone', 'leaving something to cool' or 'leaving a present' . If you think of it as meaning 'go away' you will avoid these mistakes.