AC/DC frontman Brian Johnson has detailed his devastation after being diagnosed with hearing loss in a heartfelt open letter to fans.

In March it was revealed the band would reschedule 10 US shows on its Rock or Bust World Tour and hire a guest singer to replace Johnson, whose doctors told him to “stop touring immediately”.

While the decision to replace Johnson with Guns N’ Roses frontman Axl Rose has incited excitement and condemnation, Johnson has assured fans of the iconic rock band this is not the end.

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“I want personally to explain the reason [I’ve been replaced] because I don’t believe the earlier press releases sufficiently set out what I wanted to say to our fans or the way in which I thought it should be presented,” Johnson wrote in a letter posted to AC/DC’s official website.

New AC/DC frontman Axl Rose performing at the Coachella Music Festival. Photo: Getty

“On March 7th, after a series of examinations by leading physicians in the field of hearing loss, I was advised that if I continue to perform at large venues, I risked total deafness.

“While I was horrified at the reality of the news that day, I had for a time become aware that my partial hearing loss was beginning to interfere with my performance on stage.

“Since that day, I have had several consultations with my doctors and it appears that, for the near future, I will be unable to perform on stage at arena and stadium size venues where the sound levels are beyond my current tolerance, without the risk of substantial hearing loss and possibly total deafness.”

Johnson, 68, discusses the sadness that came with his diagnosis, describing it as “the darkest day of my professional career”.

“I am personally crushed by this development more than anyone could ever imagine. The emotional experience I feel now is worse than anything I have ever in my life felt before.

“Finally, I wish to assure our fans that I am not retiring. My doctors have told me that I can continue to record in studios and I intend to do that. For the moment, my entire focus is to continue medical treatment to improve my hearing. I am hoping that in time my hearing will improve and allow me to return to live concert performances.

“While the outcome is uncertain, my attitude is optimistic. Only time will tell.”

Johnson signed the letter, “love, Brian”.