I have noticed that the dative pural suffix -(a)ibh is no longer written in modern Irish. Is it still pronounced in the spoken language?

James, a chara,
I depends on the speaker and the word in question. One that is often heard still spoken is the dative plural of 'béal' (mouth) - it is on their lips - ta se ar bhealaibh na ndaoine. Bealaibh is probably the most common dative plural still available and the only one that i have heard widely used.
Beir bua,
Tracey

I recall reading in Ó Siadhail's book _Modern Irish_ that the dative plural was still used (I think he said) in the nom. plural of certain dialects for some declensions. You should get his book is you are interested in a linguistic description of the modern dialects.

Bob

In response to Tracey's suggestion that "béalaibh" is probably the most common dative plural in use, I'll mention that in Scottish Gaelic "air beulaibh" is a very commonly used prepositional phrase meaning "in front of":

air beulaibh an taighe = os comhair an tí

And then there's 'ar na mallaibh' recently, lately.