When Jersualem is חסר (no additional 'yud' at the end), in a Tehillim I have (Shai l'Moreh), it has a footnote that it should be pronounced the full way (Ye-RU-Sha-LaY-YIM) on Chapter 79 (and I think 124). Is there a tradition to pronounce it the full way always, or possibly only on those specific chapters?
this book p. 93 mentions something about the orthography and phonology of "Yerushalayim". Summarizing some points:
- He seems to indicate that a full spelling with the 2nd yod would inidicate a tripthong making the pronunciation ayim. However, because the full spelling is rarely seen in Tanac"h, and the missing yod is the more common format, the author indiocates that the pronunciation may be more "I" or "e" sound.
- The author notes that that the missing spelling without the yod has 2 vowels, patach and hirik under the lamed. He states that based on the common pronunciation of the name Yerushalayim from the cases where it is spelled with a full yod, it's reasonable to support the idea of pronouncing it as ayi , i.e. as a tripthong even without the final yod spelling.