Interesting. I280 that runs between SJ and SF is also called The Junipero Serra Freeway, and although that term is not often used, when it is it’s usually pronounced “you-NIP-er-o”, as if the “J” weren’t even there.
It’s my impression that the interdental fricatives (as in English this thing) are definitely something that exist only in European Spanish, not in Latin American Spanish.
Of course, it’s possible that what’s being discussed here is a dental [d] sound (common in Indian languages, for example). Often Anglos are told that it’s like the sound in they, because Indians don’t have the “th” sound. It becomes a big clustermess.
Note CBEscapee’s location.
Context would have helped, of course.
At any rate, the point throughout is about the same
In spanish the D sounds closer to the D in day than to the TH in They.
It may not be a perfect match to every D of every word in english. But it is mostly closer to D than to TH even if we can come up with a handful of exceptions and special cases.
You are talking about seseo which is how the letter C (before e and i)and the letter Z are pronounced differently in America than in Spain (actually parts of Spain). Here the C, S and Z are pronounced the same. In Spain the C before e or i is pronounced like the English “th”. As an example cocinar. The second C is pronounced like an S here in Latin America and pronounced like a “th” in Madrid.
The letter D falls between the “th” in this and the hard D as in dog to various degrees. Sometimes closer to one and other times closer to the other.
A 7-bit ASCII cluj has been developed for posting in IPA on the internet where actual IPA characters aren’t supported. It’s called X-SAMPA. Until the day arrives when the world finally enjoys full Unicode implementation, we could use X-SAMPA to replace IPA in phonetics discussions here. In fact, I propose GQ should get a sticky advocating some workable IPA replacement system like X-SAMPA or Kirshenbaum or something. That way we could communicate phonetic information crisply and quickly with less noise to the signal.
In X-SAMPA:
English rodeo = r\oUdioU
Spanish rodeo = roDeo
Using Kirshenbaum:
English rodeo = roUdioU
Spanish rodeo = r<trl>oDeo