Thanks for the heads up. She did a great show and workshop at the 2014 Tampabay Uke festival in November, featuring this fascinating technique. I tried it and all I ended up with is a lot of drool on my uke.
Nice find! Earl Okin is a true master at this, and it is something that can lead to extraordinary Heights. French singer ZAZ is also know to smuggle the technique in most of her songs, blending in with the woodwinds and brass in her orchestra.
Cliff Edwards' effing or eefing is also more like mouth trumpet (buzzing; Riddle, Perkins), but sometimes reaches over to the scatting tradition which developped simultaneously(meaningless syllabes - Calloway, Fitzgerald, Vaughan, Gaillard). And even hollering/whooping (Patton, Sonny Terry) and yodelling (switching between chest and head register on the same note; Pucket, Rodgers). So fun, it leaves you lost for words...
I gave learning this a go. Not very good at it, but it does seem to be a pretty good vocal warm-up. A bit of Fanfare for the Common Man and Penny Lane, and I'm ready to sing ...
When I was a teen I could belt out a hell of a mouth trumpet, Herb Alpert and the Tijuana brass had nothing on me. Flash forward 35 years and my last try at mouth trumpet was off key and tarnished.
Maybe some cute young thing will come along and rediscover scatting next.