Sorry, I forgot that I clicked the english version of hyperdia and that it's written as english speakers pronounce it/hear it. My mistake, thinking in several languages makes me overlook those kind of things.

The sounds that ん makes in combination with the syllable after in some situation is very natural to adapt and imitate for some speakers (spanish-natives like me) that I had never realized the small variations that sometimes made it sound like an m or the other variations (for example, the way we move our lips to pronounce sanpo does make me pronounce it as sampo). I hadn't even realized that they romanize 新橋 as shimbashi! I guess you learn something everyday.