The Collaborative International Dictionary of English v.0.48:

Tootle \Too"tle\, v. i. [imp. & p. p. Tootled; p. pr. & vb. n.
   Tootling.] [Freq. of toot.]
   To toot gently, repeatedly, or continuously, on a wind
   instrument, as a flute; also, to make a similar noise by any
   means. "The tootling robin." --John Clare.
   [Webster 1913 Suppl.]