The BBC has identified the cause of the problem affecting the sound quality in the first episode of Jamaica Inn, aired on Monday night, and has promised to remedy the issue for the second episode, which will screen tonight.
Following widespread complaints about mumbling on the drama starring Jessica Brown Findlay, the BBC has spent much of the day trying to identify what caused the problem which blighted the BBC1 transmission.
However, now it appears that the issue has been resolved with the Corporation issuing a statement which said: “There were issues with the sound levels last night and for technical reasons they could not be altered during transmission.
“We are adjusting the dialogue levels in episode 2 and 3 to address audience concerns so they can enjoy the rest of the drama and would like to apologies to those viewers who were affected."
More than 100 viewers complained to the BBC, with many more taking to Twitter to bemoan the sound quality on the first episode of the three-part drama which is based on Daphne du Maurier's novel.
They insisted that the combination of the Cornish accents and the current vogue for mumbling in TV drama meant that they struggled to understand what was being said.
Those complaining included comedian Comedian Al Murray who wrote:
The actor John Challis, best known for playing Boycie in Only Fools and Horses, tweeted:
Many viewers insisted they had been forced to use subtitles to help them understand what was being said.
The series is being stripped across the schedule with the final episode showing on Wednesday night.
In it, Findlay plays the orphaned Mary Yelland who finds herself in the remote Jamaica Inn living with her Aunt Patience (Joanne Whalley) and brutal Uncle Joss (Sean Harris).
The complaints come almost a year after BBC director general Tony Hall told Radio Times that the BBC needed to look at how to stop actors "muttering" in its TV dramas.
"I don't want to sound like a grumpy old man, but I also think muttering is something we could have a look at," he said.
"Actors muttering can be testing - you find you have missed a line … you have to remember that you have an audience."