The small linking sound /w/ is written o before a, ă, e (hoa, hoặc, hoe) and u before the other vowels (huế, tuy). After q it is always the u of qu, written once: quan sounds like toán, quân like tuần.
hoa · hoặc · khoẻ · huế · tuyết · quan · quân
Quick answers
How do you pronounce Hoàng?
Block by block: a → ng → ang → oang → h → hoang → huyền → hoàng. Tone: huyền (grave accent · low falling). Read each block aloud, then compare with the recording, in a Southern or a Northern voice.
What tone is Hoàng?
huyền (grave accent · low falling)
Is Hoàng said differently in the South and the North?
South · Sài Gòn: oang = oan. North · Hà Nội: said as written.
What does “hoang” mean without the marks?
Without the marks, hoang can be several words: hoang (wild, uncultivated), hoảng (panicked, scared), hoẵng (muntjac (deer)). The marks decide which one.