Ok ... that does sound like the contactor humming. A longer video/audio version would help (30-60 seconds) to see if it varies. I would not call this critical at the moment, but it should not be doing this on such a new unit. Swap out is recommended soon. And Gary is right ... AV should be interested in analyzing this issue.
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;