Rihanna's voice against domestic violence would be "so f**king powerful" if she decided to speak out against it, says Annie Lennox.

The Bajan beauty was assaulted by her then-boyfriend Chris Brown before the Grammys three years ago, with the rapper subsequently charged with felony battery.

The 2009 assault has been making headlines recently as the pair are rumoured to have reunited.

Annie says Rihanna would be a force to be reckoned with if she decided to speak out against physical violence in relationships.

"Here is a young woman who has been through domestic violence and she could become a tremendous spokesperson for that issue but the choice is hers. It's not up to anybody else to do that," she told British newspaper The Telegraph.

"Of course if she did choose to do that it would be so f**king powerful but it's her personal right to choose it or not. We all have our issues and we have to deal with them in our own way."

Annie is disappointed with female performers who dress too seductively. The Scottish singer-songwriter agrees that sex is a part of human nature, but insists it doesn't have to be so obvious all the time.

"The world has become more sexualised. I thought the world was already sexualised when I was younger but it sells and sells and now it's just a marketing device," she said.

"The display of sexuality is part of our nature but I think when it becomes a clich and that's the only thing you are using to draw people's attention it becomes one-dimensional."