23 in when Alfred and the men are outside Odda's hall, it is possible to hear Turkeys 'gobbling' in the background, alongside the call of other farmyard animals. Turkeys are from the Americas, and would not have been introduced to Europe until at least the sixteenth century.
Just before Uhtred and Leofric leave Alfred, Beocca and Iseult to go see if Odda the Younger has betrayed their cause you can clearly hear turkeys gobble in the background. Turkeys are not indigenous to the British Isles and weren't known to Europeans until after the discovery of the Americas.
At Uhtred's estate we hear the sounds of farm animals in the background, including the sound of a turkey gobbling. Turkeys wouldn't make it to England until after the colonization of the Americas.