BBC bosses are investigating after the Strictly Come Dancing launch show was marred by sound issues.
The pre-recorded debut attracted 9.3 million viewers and a peak of 10.1 million, a record audience for a Strictly launch show.
But viewers complained that technical problems marred their enjoyment of the long-running BBC1 show, this year featuring Daisy Lowe, Lesley Joseph, Ed Balls and Laura Whitmore competing for the glitterball trophy.
A BBC spokesperson said: "We are aware of a technical problem with sound on last night's show and are looking into the cause."
Jules Edwards wrote on Twitter:? "Has anyone else got poor sound quality on BBC1 please or is my TV knackered?!"
George W.W wrote: "What's up with the sound? Thought it was one mic, then thought it was my TV but nope!"
Matthew Rimmer said: "Anyone else got sound issues? Crackling and stuff? Is it live?"
?@meggystar1 wrote: "Have they got the work experience kid doing the sound on Strictly tonight? It's appalling."
Chris Newport asked: "What's happening to the sound on Strictly Come Dancing?"
The comments come after BBC dramas Happy Valley, starring Sarah Lancashire, and Jamaica Inn were also plagued by sound problems.
The BBC's TV chief, Charlotte Moore, previously pledged to tackle problems with sound on the corporation's shows.
"It is incredibly hard to get to the bottom of where things go wrong. It's often several circumstances and it's quite hard to isolate if there is one particular problem," the director of BBC content has said.
"It is often several different problems coming together. Sound is a very exact science."
BBC1 drama Jamaica Inn sparked more than 2,000 complaints about inaudible dialogue.
BBC director-general Tony Hall recently vowed to look into the sound problems experienced by viewers of Happy Valley after the second series of the BBC One show sparked hundreds of complaints from viewers over the "shocking" sound quality.