Martin Ryan wrote "Deirtear "dlúth-diosca" nó "dlúth-cheirnín", ceapaim"
I used to hear dlúth-diosca used for CD, but since it's also used for the hard disc of the computer, dlúth-cheirnín has gained favour.
By the way, there are several terms for a mobile phone (Americans say cell phone) - we already had a choice of guthán or fón and that can now be modified by poca (pocket), so-ghluaiste (mobile) or lámh (hand)