Minor illusion

(a bit of fleece)
Make a sound or image that lasts for the
duration, untill dispelled or cast this again.
A sound can be anything, your voice, drums,
a roar. Can be continuous or in intervals.
Image is no bigger than 5Ft and is non-sensory
(except visual). Physical interaction reveals
illusion. Action to investigate against spell
save DC, when found out it becomes faint
for investigator.