O my good
I've never thougt of that! I mean, after reading your message I've been listening to myself for half an hour mumbling "a-be-to, ro-ba, ba-rro", trying to tell the difference between the allophones of "b" and... well, I failed miserably , the distinction is too subtle for me
In any case, in Hegoalde (the south of the Basque Country) the pronuntiation patterns for b,d,g are commonly presented as equivalent to castilian ones. I think my "d" at the beginning of the word and my "d" between vowels in Basque are very alike (but then, I was convinced so were they in castilian
For Iparralde (the northern part), the phonetic dissimilitudes are so clear in other aspects ( asirated h, ü sound, different accent), that -i've never payed attention nor noticed any "funny effect" with the b,d, and g... but I promise to listen more carefully in the future
. In the meantime, let's hope that other basque speakers in the forum can give you a sounder help...