I feel difficult to (can't) hear whispers/low frequency sounds. 2-3 years ago I can hear that low frequency sounds too. Now, can hear all moderate, high frequency sounds and regular conversations. I keep on headphones with maximum sound for more than 2 hours a day and sometimes it may vary from few minutes to 6 hours in a day. I also work in a manufacturing plant, full of high frequency sound from machines dynamics. What is the solution for this problem? I hope to hear low frequency sounds too.