Blindsense

You are able to use blindsight and tremorsense to radius of 30 feet in order to see your surroundings. Blindsight here enables you to perceive stationary and moving objects within range with a few exceptions (see the note on stealthed creatures). Tremorsense enables you to pinpoint the location of a creature that is moving or taking actions as long as they are touching the ground and you have a direct line of contact through the ground to the creature. You cannot "see" through walls or other significant physical barriers (at the DM's discretion). For example, if you are within fifteen feet of the edge of a chasm and there is a flying creature hovering five feet beyond the edge of the chasm and a column rising out of the chasm 20 feet from its edge, you can sense everything up to the edge of the chasm with both tremorsense and blindsight. You can sense the flying creature within range with blindsight but not tremorsense, and you cannot sense the column at all because it is beyond range.

You can sense the location of creatures (even invisible ones) if they are not stealthed. If the creature is stealthed then character must make a perception check or rely on passive perception in order to sense the location of the creature.

You are immune to the effects of magical darkness and to being blinded.

You cannot read, write, or see color with blindsense.

Effects of being deafened:

Being deafened gives disadvantage on all actions, ability checks, and dexterity saving throws.

Attacks made on a creature outside of blindsense radius are made with disadvantage if not deafened. If deafened, the attack automatically fails.

Objects or creatures not touching the ground cannot be sensed with tremorsense, and therefore if deafened you automatically fail any attack made on them.

Underwater:

You can use vibrations and water currents for tremorsense; you do not need to be touching any kind of surface for it to function.