The site's Korean is Seoul's, with the mergers that Seoul has made since the standard was written down: ㅐ and ㅔ are one vowel, ㅚ ㅙ ㅞ are all /we/, and vowel length is gone. The one habit the reference does not carry is the casual raising of a final ㅗ to ㅜ — 하고 as 하구, 나도 as 나두 — which every Seoul speaker does among friends and nobody writes.
Where: the capital and the standard; most of the country's media
The way in: Say 뭐 하구 있어? with the 하구 — that final 우 is the sound of casual Seoul.
Try a word
Anything the spelling engine can transcribe, the accent can move. Slow it down to hear the shape.
Pitch belongs to the phrase, not the word: each phrase rises over its first syllables and falls at the end, and the very first syllable starts high after an aspirated or tense consonant. Even, unhurried, and lower in the mouth than the southern dialects.
What moves, one rule at a time
In the order the mouth applies them. Every before-and-after is playable — click the IPA. The pattern is the rule as the engine runs it, for the curious.
Vowels
a final ㅗ becomes ㅜ in casual speech
o(?=$| ) → u
When: at the end of a word, in relaxed conversation — particles and verb endings above all
How: Round the lips a little more and let the tongue rise: o towards u, only on the last syllable.
The particle 도, the connective 고, the endings -고/-도 and 하고 all drift up to 두, 구, 하구 in casual Seoul speech. It is stigmatised in writing and universal in the street.