Sponge filter making a loud humming

[bongwaternanotank]

I have a Top Fin sponge filter in my tank and it's making a loud humming noise. It started after only a few days of having it. I'm using my sponge filter along with a 5-15 gallon air pump for a 10 gallon tank. If I lift the filter off the tank floor a few inches then the sound will stop, but it starts again the closer it gets to being set back down. Anyone familiar with this sort of sound from a sponge filter?

[Barnacle_Gil]

I don't use the Top Fin brand but it looks like they come with an air stone.  Try adjusting the air stone so it doesn't make contact with the the base when it's assembled.  That's the only thing that I can think of that could be making noise. 

[Andy's Fish Den]

do you have it running in a bare bottom tank? If so, the base of it may be uneven and it rocks slightly and causes the humming. Not much can be wrong with a sponge filter and to cause a buzzing sound is strange since there's no motor.