Pop sensation Avril Lavigne has said that she has "pushed" her emotional boundaries for her upcoming fifth album.

The 28-year-old singer insists that she is thrilled to have explored a different creative path, saying: ''Lyrically, I pushed myself to talk about different subjects I haven't talked about before. I didn't want to be so simple. I tried to really express myself and go deeper.

Lavigne, who is engaged to Nickelback frontman Chad Kroeger, further told Nylon magazine that she started her career as a unique artist that couldn't be compared to other female acts.

She said: ''I wasn't the girl baring her midriff with backup dancers and a headset microphone. I came out and had a lot to say with my lyrics, and I played the guitar. I had a completely different getup, stage presence, everything.''

The Complicated singer recently revealed that she has teamed up with rocker Marilyn Manson for a track on her upcoming album and admitted the ''heavier'' material came about very spontaneously.