Mike Campbell recently revealed he still grieving over his friend and bandmate Tom Petty.

In a new interview, the Heartbreakers guitarist said he finds it hard to listen to Tom Petty’s voice.

He was asked if it’s bittersweet to listen to Petty’s music and said, “Of course it is, cause Tom’s gone and that’s kind of a hard thing for me to deal with, to sit there and listen to stuff and hear his voice. It touches on some grief that I’m still processing. But I’m a big boy and I can deal with it.”

He said it really hit him when he was preparing “Live at the Fillmore 1997” compilation for release last year explaining, “There’s a lot of material and it’s important I think because some of the young people have maybe never heard the old catalogue.”

Tom Petty died of an accidental overdose on October 2, 2017.