Check your ear for water
Water often goes inside your ear while taking a bath or swimming and can cause muffled hearing in that ear. So if you are facing this problem, first of all make sure that water is not the root cause. If you suspect the presence of water in your ear, drain it out by gently tipping your affected ear down towards the shoulder. If head shaking does not work, jump slowly on the foot parallel to the affected ear, while maintaining the above position.
Clean wax build up
If you do not find water inside your ear, you might be facing ear wax impaction. It is a situation that arises when ear wax hardens or gets pushed back down the ear canal. Clean the wax build up out of your ears with the help of Q-tip. These Q-tip's are very effective when you do not have a large amount of wax built up in your ears. Be very gentle with the Q-tip when it is around or inside your ear. Pushing it hard into the ear may damage the ear drum.
Use wax softening drops
If you have a large build up of hardened wax inside your ear canal, try to remove it using wax softening drops or hydrogen peroxide. Place your head on a table with the affected ear tipped up towards the roof ceiling. Stretch your earlobe to straighten the ear canal and pour five to 10 drops and let it stay for 15 to 30 minutes to allow the wax to soften. Place a cotton ball on your ear opening and let the softened wax drain out. Then flush the external ear canal with sterile saline water.
Decrease muscle tension around the ear
Tension in the neck muscles or around your ear can also cause muffled hearing. Relax the muscles by taking a warm shower or lying down in a comfortable position to rest your neck.