The Parents Television Council, Women's rights leader Gloria Steinem and The Good Wife star Christine Baranski are among those to have criticised the show's concept.
Responding to the attacks, Heard told Collider: "It wouldn't have any effect on me, even if they had seen the show. But, they haven't seen the show so what does that matter to me?"
The actress added that questions about the NBC drama's content are "legitimate" but insisted that its female characters are "empowered by [their] sexuality".
"Women who are empowered by it and have choices based off of their sexuality are very different from the ones that are being taken advantage of," she said. "I have to make that distinction because, in 2011, we should not see the two as the same thing. They are very different."
Heard also claimed that she had been "blown away" by "the amount of trailblazers [and] trend-setters" that she met while researching The Playboy Club.
"There were many women who went on to do things, like have careers and be entrepreneurs," she said. "There are women who have talked to us about their experiences. They might exist, but I have yet to meet an ex-Bunny who's disgruntled about her experience."
The Playboy Club begins on Monday, September 19 at 10/9c.
> Playboy Club not inappropriate, says NBC chief
Watch a clip from The Playboy Club below: