well if i didn't, i've never seen it done before so don't flame!
I'll call it super trilling!! basically, you perform a hammer-on trill, say --7---9--- on G... but instead of normal hammeron, you will "tap" with say your ring finger (left hand) then tap with your tapping finger (index/middle/etc) of your right hand... in VERY quick succession: kinda like:
G:---7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-
-------L------R------L------R-----L-----R------L-----R-----L------
key: L= left hand ring, R = right hand middle
if done right (very fast) it sounds like a super quick trill, like machine gun style! let me know if I need to explain it better
I'll call it super trilling!! basically, you perform a hammer-on trill, say --7---9--- on G... but instead of normal hammeron, you will "tap" with say your ring finger (left hand) then tap with your tapping finger (index/middle/etc) of your right hand... in VERY quick succession: kinda like:
G:---7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-h9-p7-
-------L------R------L------R-----L-----R------L-----R-----L------
key: L= left hand ring, R = right hand middle
if done right (very fast) it sounds like a super quick trill, like machine gun style! let me know if I need to explain it better