noisey pump!

There are different types of pump noise.
If you're talking about vibration as far as noise goes, some pumps or pump piping need to be placed on a sponge, or buffered to keep vibration noise down.
Note how I place a sponge between the pipe and sump side to keep hum down.

This Mag drive pump in another sump tends to vibrate loudly if placed directly on the glass bottom, so it is on a filter sponge to keep noise at a minimum.

If the noise is from cavitation (a crackling sound) that is another matter.

I agree, be careful of kitchen sponges, some are anti microbial/anti fungal which could kill your fish.
I use large filter sponges made to be mechanical and bio-filter media for ponds, the sponges used in large pond filters are perfect for my use, and sometimes available at garden centers that have pond supplies.
Along with the noise reduction, they will provide areas for beneficial bacteria, especially near pump intakes where there is constant water movement.

I agree, be careful of kitchen sponges, some are anti microbial/anti fungal which could kill your fish.
I use large filter sponges made to be mechanical and bio-filter media for ponds, the sponges used in large pond filters are perfect for my use, and sometimes available at garden centers that have pond supplies.
Along with the noise reduction, they will provide areas for beneficial bacteria, especially near pump intakes where there is constant water movement.