The 31-year-old star has been dating the Muse rocker for almost a year and they are expecting a baby together.
Speaking about her British boyfriend's accent on The Graham Norton Show, she said: 'It was the phone calls that signed the deal for me - hearing his voice on the phone. It was so lovely.'
She added: 'He has corrected some of my use of English!'
Hudson already has a seven-year-old son Ryder from her marriage to Chris Robinson and she admitted Bellamy is different to American men.
She said: 'I never thought I would notice the difference but there are a lot of differences, it's just a different way, he is polite and kind and so sweet.'