If you have tinnitus, 75dB is not the cause. Unless it is 75dB real continuous and for hours. But even then that will usually only be a short term loss. Like when you get out of the car after a long trip, the road noise means you need a few hours to get your fine hearing back.
At 18 you should only be hearing ringing after a 105dB rock concert. Even then it should be gone by the next day. But tinnitus can have many different causes, and even be totally unrelated to loud sound exposure. Drugs like aspirin, and even ibuprofen can cause it, although again it should take a lot over a long time. I gave myself tinnitus one time by taking a boatload of aspirin for a bad burn. Point being, do a little research, maybe even see a doctor.
At 18 you should only be hearing ringing after a 105dB rock concert. Even then it should be gone by the next day. But tinnitus can have many different causes, and even be totally unrelated to loud sound exposure. Drugs like aspirin, and even ibuprofen can cause it, although again it should take a lot over a long time. I gave myself tinnitus one time by taking a boatload of aspirin for a bad burn. Point being, do a little research, maybe even see a doctor.