I’m looking at an online grammar of Catalan. The author says
b / v (which in Catalan have the same sound) and d sound like in Engl. b or d, except when they are placed between two vowels; in this case, the pronunciation is “smoother” (e. g. baralla / roba, valor / cava, dia / cada). In the Valencian dialect, the intervocalic -d- even has a tendency to disappear (e. g. vesprada = vesprà ). We represent the “smoother” b or d as [bh] and [dh].
Unfortunately, as is all too often the case, I’m left trying to interpret what the sounds actually are. The problem isn’t so much d, which would would appear to be [d] word-initially (and post-consonantally?—yes) and [ð] intervocalically, but b/v. These “have the same sound”, apparently [b] word-initially, but a “smoother” pronunciation between vowels.
Like Catalan d, which is probably an approximant between vowels, b/v is probably a bilabial approximant [β] in an intervocalic position.
The problem is cleared up by going to this site. b and v are [b] word-initially, and [β] between vowels.
I find that value descriptions of sounds in a language (e.g. “smoother”) are irritating because they tell no one anything. If you say, “bilabial approximant”, I know what you mean. If you say a sound is smoother, I might as well assume that it’s a spiv with a pencil moustache who does jobs for Fat Boy Malone’s mob.
Oh dear. I think I’m turning into Language Log.