Why can't humans hear high frequencies?

Related questions

1. What causes tinnitus to get louder?
2. Can humans hear below 20hz?
3. How can I test my hearing?
4. What vitamins help hearing?
5. Can something be so loud it kills you?
6. What frequency can kill a human?
7. Is ultrasonic sound harmful to humans?
8. Do cats know their names?
9. How far can a cat hear?
10. What vitamin deficiency causes ringing in the ears?

Tags

1. #oscillates
2. #pitch
3. #resulting
4. #eardrums
5. #consider
6. #sound
7. #sounds
8. #whistles
9. #canines
10. #evolved
11. #frequency
12. #which
13. #because
14. #detect
15. #higher