O think the ears
Indirectly, yes. The skin passes feelings of soft, hard, cold, or hot to the brain. The eyes send images. The nose sends smells, and the mouth sends flavors. The ears send sounds and balance. These are all processed in the brain.
your nervous system sends messages to your brain
I'm guessing the ear, since it mostly deals with sounds/sound waves and sends them to your brain...
Your brain sends singles to your body and your heart sends blood through your body
There are several (a lot) of tiny hair like structures inside the ear will vibrate in response to certain sound frequencies. When a hair vibrates, it stimulates a particular cell which sends a signal to the neurons next to it, to the brain. The brain takes all of the inputs and can interpret that as sounds and frequencies. Louder sounds will cause it to vibrate more, so the brain can interpret that as well.
The retina detects light and the optical nerve sends the signal to the brain.
Brain sends signal through spinal cord to nerves. Nerves contract which muscle to move and sends a message back to the brain. BOOM! Movement.
Crude sounds are formed into speech through a complex process involving the brain, vocal cords, lungs, mouth, and throat. The brain sends signals to the vocal cords to vibrate and produce sound, which is then shaped by the mouth and throat into specific sounds and words. This process allows us to create and communicate in a wide variety of languages and dialects.
The brain.
Retina
sensory neurons
When you want to move a muscle, your brain sends a message out to the muscle you want to move, and the muscle sends a message back to your brain that your moving it and where.