What phonetic language an dictionary is supported by Siri on iOS? I want to convince Siri to properly pronounce and recognise some of my contacts.

I know that I need to tweak the 3 fields: Phonetic First Name, Phonetic Last Name and Nickname for that.

Still, I am missing some very important information:


What phonetic language does it use as it does not seem to be IPA
Where can I find the list of possible sounds and their letters
Just like it sounds.

Obama => Oh Ba mu