A bunch of nerves that are connected to your spine also connect to your brain and sends it the info we need and sends out other information throughout your body
Loud noise can damage cells and membranes in the cochlea. Listening to loud noise for a long time can overwork hair cells in the ear, which can cause these cells to die. The hearing loss progresses as long as the exposure continues. Harmful effects might continue even after noise exposure has stopped.
The answer is 50%.
From the 'National Affairs' website, they conducted a study where they found that less than 20% of couples who married in 1950 ended up divorced, about 50% of couples who married in 1970 did.
And in regards to the basic unit of society question; the answer would be family. Family is the basic unit of society as it forms community and is the nucleus of civilisation.