Why Do People Hear Different Sounds?

just curious...........

why do we all seem to perceive different sounds/volumes?

ie I have a constant shhhhhhhhhh centrally........hiss/ring in my right ear........and eeeeeeee intermittently in both ears.....

is the noise correlated with the underlying cause/trigger of the t?

 

I've read high pitched is related to hearing loss... But really I have no idea.

I have a high pitched shhhhhhhhh sound in both ears