Yes, the Language Log posting is pretty good. The double-ells are basically a '/tl/ sound, with the l being a fricative not unlike the Welsh ll sound. It's so amazing that when I was studying linguistics back in the late '70s, you needed about $100K worth of machinery to make one of those spectrograms and now you can do it on a laptop with open source, free software.

Ceci n'est pas un seing.