It's mostly dependent on age and sex. You're born with a hearing range of about 20 Hz to 20 kHz. It's really hard to lose hearing on the low end, it's most likely your sub that can't do it, but the high-end decreases by age, and it's faster for males. I'm only 25, and my hearing tops out at 17 kHz, which is normal for a male of my age, and is the same as my mother's hearing limits. Adult males usually hear up to around 14 kHz.