Throughout the day I have been losing more low frequency hearing, and I really don't know why whatsoever (possibly road noise?), but it could be the earplugs I am wearing. I wear deep fitting foam earplugs which are great for external sounds. They also seem to minimize the occlusion effect to some degree. I am very careful to fit them in and take them out slowly. The problem is, fitting them tightly may present a positive pressure gradient which could be bad, and they can make 60+ low frequency decibel sounds when fitting them. I'm also not so sure they are accounting for occlusion effect. When I talk louder, for instance, I don't hear loudness in my head but I certainly feel it in my sinuses and it HURTS and hurts my head. Furthermore, on two occasions when I have gently pulled them out, I have had a loud wishy washy humming sound in the left ear which feels like a blood rush, which has lasted and dampened low and high frequency hearing. They have even caused a negative pressure gradient in my eustachian tubes. Am I damaging my own hearing with these earplugs???