I have been reading a new book called Sengoídelc. It is about Old Irish, and was published recently, and apparently someone on this list, Dennis King, is credited with a contribution too. :-)
I found chapter 3 on the pronunciation of Old Irish unsatisfactory for a number of reasons. First, the Greek letters μ and ν are used to represent a nasalised labial fricative and a lax n respectively. The ν is particularly misleading, because it looks like a v. The other problem is that the labial fricatives are stated as being exactly the same as the English f and v - ie labiodental and not bilabial, and the book uses ɸ, not to represent a bilabial sound, but to show when an ph is being transcribed and not an f.
There is another throwaway comments in this chapter. The ɣ is confidently stated as being the same as the Ukrainian sound. Does Ukrainian have this sound? I think he is talking about the Ukrainian sound ɦ, a voiced h, nothing like ɣ.
I can't be sure, but it seems to me that the author, David Stifter, is saying that Old Irish had the following consonants (using the IPA). YOu need to use a Unicode font, like Arial to view this.
| | | Bilabial | Dental | Alveolar | Post-alveolar | Palatal | Velar |
| Plosive | Velarized | pʰ b | tʰ d | | | | kʰ g |
| Palatalized | pʲ bʲ | | tʲ dʲ | | | kʲ gʲ |
| Nasal | Velarized | m | n̪ˠ | n | | | ŋ |
| Palatalized | mʲ | | nʲ | | ɲ (=N') | ŋʲ |
| Fricative | Velarized | ɸ β | θ ð | s | | ç (=x') | x ɣ |
| Palatalized | ɸʲ βʲ | θʲ ðʲ | | ʃ (=s') | | |
| Nasalised fricative | Velarized | β̃ | | | | | |
| Palatalized | β̃ʲ | | | | | |
| Approximant | Velarized | | | r ɾ | | | |
| Palatalized | | | rʲ ɾʲ | | j (=ɣ', or would ʝ be better?) | |
| Lateral approximant | Velarized | | l̪ˠ | l | | | |
| Palatalized | | | lʲ | | ʎ (=L') | |
|
