Channel Nine's The Voice ratings dropped below the two million viewership mark on Tuesday, registering only 1.937 million (peaking at 2.345 million), according to initial OzTAM figures.

This developed as The Voice's axed contestant, Carmen Smith, is set to make an appearance on Wednesday night in Seven's Australia's Got Talent.

"I'll be singing with someone I absolutely love," singer Guy Sebastian said in the latest promo for Australia's Got Talent.

Sebastian, who is signed to Seven's other reality show The X Factor, has openly spoken about his frustration over The Voice management's decision to let Smith go after she appeared in his latest music video for his single, "Gold."

Nine reportedly offered them to sing Gold in The Voice, but the two had decided to perform at Seven instead.

Meawhile, Seven has been promoting Smith's appearance with Sebastian in their network, in a move that seemed to be all about the ratings game.

Smith and Sebastian will be seen at Seven's singing show at 7:30pm Wednesday in Melbourne, Adelaide and Perth, and the same time on Thursday in Sydney and Brisbane.

Even with The Voice's drop in ratings, Nine still won Tuesday night's ratings race with a 30.1 per cent channel share. Seven had a 21.2 per cent channel share. Both networks have four shows each in the Top 10 shows during primetime Tuesday, with The Voice still leading the rankings.