Also damage means that you still hear those frequencies but only at higher volume so you may hear a dog whistle but not if its too quiet or far away hence the tinnitus
In most cases each ear has damage at different frequencies so used together they can hear sort of okay but because of the imbalance of hearing signals coming into the brain you have a tinnitus recreating those left and right poor frequencies separately and mixing it back amplified into the brain
That's why the tinnitus seems louder than the actual hearing loss