Roughing up the walls by hanging things on it like clocks and racks and pictures does not diminish noise but it does muddy it, and that can make it easier to understand sounds like speech and music; sort of like dampening an echo.

Soft stuff on the walls (unless you take it to extremes) tends to muffle the higher frequencies only. To dampen lower frequencies like toilet user noises the best remedies are often decoupling and mass.

In new construction it's easy to mount a layer of wallboard on springy metal strips rather than screwing them firmly to studs. That allows dampening sonic energy by letting things move a bit. In my house I have a bathroom sharing a wall with a bedroom and I put a layer of 5/8 inch rock, 1/2 inch paper board (Homasote), and 1/2 rock. All three layers added mass that absorbs sound but each layer has a different resonant frequency, so fewer noises get through.

Staggering studs, like putting 2X3 studs on a 2X4 plate also helps as the wallboard in one room is not attached to the same structure as wallboard in the other room except at the top and bottom, and even they could be separated too, roughly like a split firewall.

But ultimately there's no such thing as soundproofing, just diminishing.

Retrofitting sound deadening will greatly reduce your embarrassment.

Add Quietrock or equivalent to the interior walls or use GreenGlue and another layer of drywall.

And don't overlook remedying the obvious, such as a poorly fitting door with a large undercut or an unnecessary air return.

If you do want to hang your quilts make sure to keep them out of direct sunlight and make sure they do not touch the wood directly or they will become permanently discolored. The beat way to store them is to keep them rolled in a dark space, and if you have to fold them refold in a different direction (probably when you think about it is good enough) so they do not develop permenant creases and tear.

Sorry. I'm an archivist and a quilter. Good luck finding an easy solution for sound deadening.

There are 3 methods in a sound reduction design: mass , resiliency and absorption in order of effectiveness.

Hanging quilts is not one of them; a quilt will simply reduce the degree to which sound bounces within a room by absorbing some of it which adds to your comfort but it doesn't reduce sound transfer from another room or floor.

The most effective method is to thicken the wall material and increase its mass so that sound simply can't vibrate it and transfer energy to the air on the other side. Masonry is better than gypsum board. Mass loaded vinyl is a thin version of this method.

The second most effective (and thinner) method is to build a surface that can move when sound energy strikes it. The most common way is to put resilient channels behind gypsum board or to use special gypsum board with a resilient core or to adhere gypsum board with a resilient adhesive.

The third method is absorption which is not very effective but it can help when the other methods have been neglected ⦠and it can't hurt. As sound passes through insulation it loses some of its energy but the thickness of a wall is not enough to make much of a difference. However, when sound enters through a crack on one side of the wall and tries to exit through a crack on the other side, the sound is forced to travel some distance though the wall cavity and that can be enough absorption to make a difference. Insulation in a wall with a door is of little or no use.

It also helps to prevent back to back electrical outlets and ducts grilles and to use heavy doors with small undercuts or perimeter gaskets. Old doors sometimes have "drop seals" that drop to close the gap under the door when the door closes.

It also helps to not put bathrooms above living spaces and to avoid long horizontal waste pipe runs. When waste pipes are above living spaces it is best to use cast iron pipes and quick flushing quiet toilets.

Noisy plumbing is often due to the plastic pipe they use nowadays. Nothing like cast iron waste pipes to quiet that noise down.

Spray foam insulation will help with some noise control.

Area rugs need not be expensive but will add warmth and sound control to the space, so I'd put them down, with or without a cat.

spray foam is an expensive material for interior walls.
I'd look into adding blown insulation in these walls.

as renovator8 says, offsetting outlets etc transfer sound
through the walls.

see which walls are shared with bathrooms & have
blown insulation company insulate these walls.
then repaint drill caps.

short of hat channels/quietrock & other 'big' projects
adding insulation is a smaller less intrusive job.

best of luck.

Sound transfers in our house through the ducts, and I am not talking about back to back grills. If someone is in one room talking it can be heard in a room on the other end of the house. Not sure there is anything we can do about it at this point, but if someone has a suggestion I am all ears.