Twist is continuously twisted along its length to prevent the cable acting as a loop aerial. A cable that is untwisted has a larger surface area, therefore has a greater ability to attract RFI/EMI signals generated from Radio, Wifi, Mobile Phones and even central heating systems.
Sold by the metre.
Specification below:
2 core twisted pair loudspeaker cable
0.75 sq. mm tinned copper conductors
1.2 mm silicone rubber insulation