Absurd Minds

Sound is a very integral part of the game. Playing with no sound can (perhaps) sharpen your visual abilities, but playing with sound adds yet another method of gaining information about your surrounds and your enemy.

Learn what different parts of the map sound like. Learn the difference between the sound of walking on sand and the sound of walking on hard ground, and learn how those are different from walking on a plank or through water. Then learn where on the map these different textures are. Know that if you hear the squeaky sound of a plank, then the enemy is definitely here. Know that if you hear a door open, then they must be over there.

Learn the sounds of the different weapons. A HE Grenade makes a much different sound when it's thrown than a flashbang does. It dinks differently on the ground. Knowing the difference in the sound will make it so you don't turn your back to a HE grenade (thinking it's a flash) and then get shot in the back. Learn the difference between a AK and a Galil. It will help you decide if you need to keep your distance/cover, or if a rush attack would be more successful.

Once you can learn the sounds of your enemies, start to pay attention to your sounds, and use them as part of your tactics. A smoke grenade and a flash grenade sound very similar, so throw smokes instead of flashes to trick the enemy into turning around. Open a door to make the door-open sound, but then retreat back and don't enter. Or have one teammate running and some walking, so the enemy is confused about how many of you there are.