[H2Ogal]

The bubbles are actually soothing to hear as I have found out but the darn buzzing from the air pump is what really ruins my sleep.

I have it on a nice thick yellow sponge - 3" thick - yet the buzz is merely reduced by about 10%. I am thinking about putting it on a timer.

Only have it on 6AM - 12AM. 18 hours per day should be more than enough aeration?

The sponge filter is providing bacterial filtration as well as aeration, and the bacterial colony needs flowing water to stay oxygenated; turning off the air could damage the filter bacteria. You might want to try replacing your air pump. That one might be damage, old or just noisy. Another brand might be quieter.