I've seen nothing on a trilled "L" sound anywhere. I've tried producing the trilled "L" sound and I can get something that seems similar. Is it possible to trill an "L" and if so are there any languages that use this sound?
3 Answers
It seems to me that lateral and trill are mutually exclusive - trills require repeated opening and fully closing, while laterals require a state of half-closure. If you drop the sides of your tongue to make a lateral, you make trilling impossible.
There are lateral flaps, though, which seem to be not uncommon - Japanese has one, /ɺ/.
There is an Alveolar Lateral Trill, it has this symbol; /rˡ/ and there a video of it; http://www.youtube.com/watch?v=kr4_zYBRaWY&api_format=3&vndel=watch&app=desktop
I can do something I'd categorize as trilled L: I close the air flow in my mouth by placing my tongue behind my upper teeth; then I blow the air out, creating very small opening on the sides. It sounds like a child mimicking a fart :/ It can be either a trill or fricative, depending on how the air gets out. So, I think it's possible. :-) I've never seen it in any language.