Published Wednesday, 28 May 2014
The first episode of the three-part show aired on Sunday but many viewers were left struggling to hear the characters speaking.
Almost 250 frustrated viewers have complained about the sound quality, demanding BBC chiefs act to improve the show before the next episode is broadcast on Sunday.
The controversy comes just weeks after more than 2,000 viewers complained about the poor sound quality in Jessica Brown Findlay's adaptation of Jamaica Inn last month.
A BBC spokeswoman said: "A wide range of factors can influence audibility and we will continue to work with the industry on this important subject."