It depends on what sound is bothersome to you. If you don't mind the sound of the water bubbling, you can get a small sponge filter with a quiet air pump. Something like
http://www.amazon.com/gp/product/B00HYEO8H6/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/gp/product/B0009YJ4N6/ref=oh_details_o02_s00_i01?ie=UTF8&psc=1
I have that air pump on the carpeted floor below the tank. It hums very quietly, as long as it isn't touching anything. The sponge filter inside the tank does create a bubbling sound. Some people may find that bothersome; others may find it relaxing.
http://www.amazon.com/gp/product/B00HYEO8H6/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/gp/product/B0009YJ4N6/ref=oh_details_o02_s00_i01?ie=UTF8&psc=1
I have that air pump on the carpeted floor below the tank. It hums very quietly, as long as it isn't touching anything. The sponge filter inside the tank does create a bubbling sound. Some people may find that bothersome; others may find it relaxing.
